Merge branch 'feature/btc-native-send' into fix/multisig-first-signer-deep-link

# Conflicts:
#	feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/BridgeFragment.kt
#	feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/BridgeViewModel.kt
#	feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/di/BridgeModule.kt

.github/scripts/run_balances_test.sh

@@ -35,7 +35,7 @@ t.start()
 
 def run():
   os.system('adb wait-for-device')
-  p = sp.Popen('adb shell am instrument -w -m -e debug false -e class "io.novafoundation.nova.balances.BalancesIntegrationTest" io.pezkuwichain.wallet.debug.test/io.qameta.allure.android.runners.AllureAndroidJUnitRunner',
+  p = sp.Popen('adb shell am instrument -w -m -e debug false -e package "io.novafoundation.nova.balances" io.pezkuwichain.wallet.debug.test/io.qameta.allure.android.runners.AllureAndroidJUnitRunner',
                shell=True, stdout=sp.PIPE, stderr=sp.PIPE, stdin=sp.PIPE)
   return p.communicate()
 success = re.compile(r'OK \(\d+ tests\)')

.github/workflows/balances_test.yml

@@ -1,6 +1,7 @@
 name: Run balances tests
 
 on:
+  pull_request:
   workflow_dispatch:
   schedule:
     - cron: '0 */8 * * *'
@@ -43,13 +44,50 @@ jobs:
           sudo udevadm control --reload-rules
           sudo udevadm trigger --name-match=kvm
 
+      - name: AVD cache
+        uses: actions/cache@v4
+        id: avd-cache
+        with:
+          path: |
+            ~/.android/avd/*
+            ~/.android/adb*
+          key: avd-29-nexus6-x86_64-v1
+
+      - name: Create AVD and generate snapshot for caching
+        if: steps.avd-cache.outputs.cache-hit != 'true'
+        uses: reactivecircus/android-emulator-runner@v2
+        with:
+          disable-animations: false
+          profile: Nexus 6
+          api-level: 29
+          arch: x86_64
+          force-avd-creation: false
+          emulator-options: -no-window -gpu swiftshader_indirect -noaudio -no-boot-anim -camera-back none
+          script: echo "Generated AVD snapshot for caching."
+
       - name: Run tests
+        id: run-tests-attempt-1
+        continue-on-error: true
         uses: reactivecircus/android-emulator-runner@v2
         with:
           disable-animations: true
           profile: Nexus 6
           api-level: 29
           arch: x86_64
+          force-avd-creation: false
+          emulator-options: -no-window -gpu swiftshader_indirect -no-snapshot-save -noaudio -no-boot-anim
+          script: .github/scripts/run_balances_test.sh
+
+      - name: Run tests (retry - reactivecircus/android-emulator-runner flakes on SDK download/emulator boot)
+        if: steps.run-tests-attempt-1.outcome == 'failure'
+        uses: reactivecircus/android-emulator-runner@v2
+        with:
+          disable-animations: true
+          profile: Nexus 6
+          api-level: 29
+          arch: x86_64
+          force-avd-creation: false
+          emulator-options: -no-window -gpu swiftshader_indirect -no-snapshot-save -noaudio -no-boot-anim
           script: .github/scripts/run_balances_test.sh
 
       - uses: actions/upload-artifact@v4

.github/workflows/install/action.yml

@@ -18,7 +18,27 @@ runs:
     - name: Install NDK
       run: |
         SDKMANAGER=$(find ${ANDROID_SDK_ROOT}/cmdline-tools -name sdkmanager -type f 2>/dev/null | head -1)
-        echo "y" | sudo ${SDKMANAGER} --install "ndk;26.1.10909125" --sdk_root=${ANDROID_SDK_ROOT}
+        NDK_PACKAGE="ndk;26.1.10909125"
+
+        # sdkmanager's download of the ~1GB NDK zip from Google's CDN occasionally comes back truncated/corrupted
+        # ("Error on ZipFile unknown archive") with no built-in retry, taking down the whole build for a purely
+        # transient network blip. Retry with cleanup between attempts: sdkmanager can otherwise resume from the
+        # same corrupted partial file instead of re-fetching, making a naive retry fail identically every time.
+        for attempt in 1 2 3; do
+          echo "NDK install attempt $attempt/3"
+          if echo "y" | sudo ${SDKMANAGER} --install "$NDK_PACKAGE" --sdk_root=${ANDROID_SDK_ROOT}; then
+            echo "NDK installed successfully"
+            exit 0
+          fi
+
+          echo "Attempt $attempt failed - clearing any partial/corrupted download before retrying"
+          sudo rm -rf "${ANDROID_SDK_ROOT}/ndk/26.1.10909125"
+          sudo find "${ANDROID_SDK_ROOT}" -maxdepth 1 -name "tmp*" -exec rm -rf {} +
+          sleep 10
+        done
+
+        echo "NDK install failed after 3 attempts"
+        exit 1
       shell: bash
 
     - name: Set ndk.dir in local.properties

app/build.gradle

@@ -324,6 +324,7 @@ dependencies {
     androidTestImplementation androidTestRunnerDep
     androidTestImplementation androidTestRulesDep
     androidTestImplementation androidJunitDep
+    androidTestImplementation scalarsConverterDep
 
     androidTestImplementation allureKotlinModel
     androidTestImplementation allureKotlinCommons

app/src/androidTest/java/io/novafoundation/nova/balances/PezkuwiFullArchitectureBalancesTest.kt

@@ -0,0 +1,154 @@
+package io.novafoundation.nova.balances
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import com.google.gson.Gson
+import io.novafoundation.nova.common.di.FeatureUtils
+import io.novafoundation.nova.common.utils.fromJson
+import io.novafoundation.nova.core.model.CryptoType
+import io.novafoundation.nova.core_db.dao.AssetDao
+import io.novafoundation.nova.core_db.dao.ChainAssetDao
+import io.novafoundation.nova.core_db.dao.MetaAccountDao
+import io.novafoundation.nova.core_db.di.DbApi
+import io.novafoundation.nova.core_db.model.chain.account.MetaAccountLocal
+import io.novafoundation.nova.feature_assets.di.AssetsFeatureApi
+import io.novafoundation.nova.runtime.BuildConfig.TEST_ASSETS_URL
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.ss58.SS58Encoder.toAccountId
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeoutOrNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.net.URL
+import kotlin.time.Duration.Companion.seconds
+
+private data class AssetFixture(val chainId: String, val chainName: String, val assetId: Int, val symbol: String)
+private data class AssetsFixtureFile(val account: String, val assets: List<AssetFixture>)
+
+/**
+ * Exercises the ACTUAL production balance-sync pipeline (BalancesUpdateSystem -> AssetCache/AssetDao) end to
+ * end, unlike [BalancesIntegrationTest] which bypasses it entirely via a direct low-level storage query. This
+ * is meant to answer one question with hard evidence, not speculation: for a real, well-funded mainnet Founder
+ * account, does the app's real, running background sync ever write an `assets` cache row for every asset in
+ * wallet-utils' pezkuwi_assets_for_testBalance.json (HEZ/PEZ/USDT/DOT/ETH/BTC across Pezkuwi's chains) - not
+ * just the native balance on one chain, which is all the older [BalancesIntegrationTest] fixture covers.
+ *
+ * A single watch-only account is created and selected once, so a single BalancesUpdateSystem run has to
+ * successfully sync every asset in the fixture - this is what actually caught the 2026-07-09 HEZ-on-Asset-Hub
+ * silent sync failure (5 of 6 assets on that chain synced fine; only HEZ silently never did).
+ *
+ * BalancesUpdateSystem.start() is a cold flow - in production it's only ever collected by RootInteractor,
+ * which is wired to the root Activity/ViewModel lifecycle. A bare instrumented test never launches that
+ * Activity, so we collect it ourselves here via the same AssetsFeatureApi.updateSystem instance the real app
+ * uses, instead of relying on app UI lifecycle to start it.
+ *
+ * If this test fails, the standard per-updater error logs already wired into BalancesUpdateSystem/
+ * FullSyncPaymentUpdater/NativeAssetBalance/StatemineAssetBalance show exactly which decision branch or
+ * exception is responsible - not another layer of inference from silence.
+ */
+class PezkuwiFullArchitectureBalancesTest {
+
+    // Standard BIP44 Ethereum derivation (m/44'/60'/0'/0/0) from the same already-verified Founder mnemonic
+    // used for the substrate address below - this is exactly what Nova/Pezkuwi Wallet's own unified account
+    // creation derives when a single seed produces both a substrate and an Ethereum account. No dedicated
+    // "founder EVM wallet" record exists anywhere else, so this is the correct, non-fabricated way to get a
+    // real EVM address to test USDT-on-Ethereum sync with - it doesn't need to hold any balance, since this
+    // test only asserts a row gets written (see below), not that the balance is non-zero.
+    private val founderEthereumAddress = "0x1aa2EA1292c62BdC6E49E0C12134263efc73713A"
+    private val ethereumChainId = "eip155:1"
+
+    private val context = ApplicationProvider.getApplicationContext<Context>()
+
+    private val dbApi = FeatureUtils.getFeature<DbApi>(context, DbApi::class.java)
+    private val metaAccountDao = dbApi.metaAccountDao()
+    private val assetDao: AssetDao = dbApi.provideAssetDao()
+    private val chainAssetDao: ChainAssetDao = dbApi.chainAssetDao()
+
+    private val assetsFeatureApi = FeatureUtils.getFeature<AssetsFeatureApi>(context, AssetsFeatureApi::class.java)
+
+    @Test
+    fun testPezkuwiEcosystemAssetsActuallySync() = runBlocking {
+        val fixture: AssetsFixtureFile = Gson().fromJson(URL(TEST_ASSETS_URL).readText())
+
+        val updateSystemJob = launch { assetsFeatureApi.updateSystem.start().collect {} }
+
+        try {
+            val metaId = insertAndSelectWatchAccount(metaAccountDao, fixture.account, founderEthereumAddress)
+
+            // Ethereum's USDT isn't in the JSON fixture because its assetId isn't a fixed, known integer like
+            // Substrate assets - EvmAssetsSyncService computes it as a hash of the ERC20 contract address at
+            // sync time (see chainAssetIdOfErc20Token()), so it has to be resolved dynamically here instead of
+            // hardcoded. This closes out the third of the three originally-reported symptoms (Tron disabled,
+            // Pezkuwi tokens missing, USDT on Polkadot AH/Ethereum missing) - the first two are already covered
+            // by the fixture-driven assets above.
+            val ethereumUsdtAssetId = withTimeoutOrNull(30.seconds) {
+                var assetId: Int? = null
+                while (assetId == null) {
+                    assetId = chainAssetDao.getEnabledAssets()
+                        .firstOrNull { it.chainId == ethereumChainId && it.symbol == "USDT" }
+                        ?.id
+                    if (assetId == null) delay(2.seconds)
+                }
+                assetId
+            }
+            assertTrue(
+                "USDT was never registered as an enabled asset on Ethereum (chainId=$ethereumChainId) within 30s - " +
+                    "EvmAssetsSyncService may have failed to sync from EVM_ASSETS_URL.",
+                ethereumUsdtAssetId != null
+            )
+
+            val stillMissing = (
+                fixture.assets +
+                    AssetFixture(ethereumChainId, "Ethereum", ethereumUsdtAssetId!!, "USDT")
+                ).toMutableList()
+
+            withTimeoutOrNull(120.seconds) {
+                while (stillMissing.isNotEmpty()) {
+                    val found = stillMissing.filter { asset ->
+                        assetDao.getAsset(metaId, asset.chainId, asset.assetId) != null
+                    }
+                    stillMissing.removeAll(found)
+                    if (stillMissing.isNotEmpty()) delay(2.seconds)
+                }
+            }
+
+            assertTrue(
+                "No `assets` row was ever written for: ${stillMissing.joinToString { "${it.symbol} on ${it.chainName}" }} " +
+                    "(metaId=$metaId) within 120s, out of ${fixture.assets.size + 1} total. The real BalancesUpdateSystem " +
+                    "pipeline never completed a sync for these - check the standard FullSyncPaymentUpdater/" +
+                    "NativeAssetBalance/StatemineAssetBalance/EvmErc20AssetBalance error logs in logcat.",
+                stillMissing.isEmpty()
+            )
+        } finally {
+            updateSystemJob.cancel()
+        }
+    }
+
+    private suspend fun insertAndSelectWatchAccount(dao: MetaAccountDao, substrateAddress: String, ethereumAddress: String): Long {
+        val accountId = substrateAddress.toAccountId()
+        val evmAddress = ethereumAddress.removePrefix("0x").fromHex()
+
+        val metaAccount = MetaAccountLocal(
+            substratePublicKey = accountId,
+            substrateCryptoType = CryptoType.SR25519,
+            substrateAccountId = accountId,
+            ethereumPublicKey = null,
+            ethereumAddress = evmAddress,
+            name = "PezkuwiFullArchitectureBalancesTest",
+            parentMetaId = null,
+            isSelected = false,
+            position = 0,
+            type = MetaAccountLocal.Type.WATCH_ONLY,
+            status = MetaAccountLocal.Status.ACTIVE,
+            globallyUniqueId = MetaAccountLocal.generateGloballyUniqueId(),
+            typeExtras = null
+        )
+
+        val metaId = dao.insertMetaAccount(metaAccount)
+        dao.selectMetaAccount(metaId)
+
+        return metaId
+    }
+}

app/src/androidTest/java/io/novafoundation/nova/balances/TronBalancesIntegrationTest.kt

@@ -0,0 +1,97 @@
+package io.novafoundation.nova.balances
+
+import io.novafoundation.nova.common.utils.tronAddressToAccountId
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.RealTronGridApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.RetrofitTronGridApi
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.runBlocking
+import okhttp3.OkHttpClient
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import retrofit2.HttpException
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
+import retrofit2.converter.scalars.ScalarsConverterFactory
+import java.math.BigInteger
+
+/**
+ * Tron is a REST API (TronGrid), not a Substrate runtime - it has no ChainConnection/RuntimeProvider and isn't
+ * reachable through [BalancesIntegrationTest]'s chainRegistry-based mechanism at all. This exercises the exact
+ * same [io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi] the production app uses for
+ * balance reads (see TronNativeAssetBalance/Trc20AssetBalance), just via a standalone Retrofit client instead of
+ * the full DI graph, since TronGridApi isn't exposed through a public feature API for tests to reach.
+ *
+ * Test account is the mainnet Founder's Tron address, verified live via TronGrid's public API on 2026-07-09 to
+ * hold a substantial non-zero balance of both native TRX and TRC-20 USDT - not a guessed or empty account.
+ */
+class TronBalancesIntegrationTest {
+
+    private val testAddress = "TDGZ4GfvCRe1d8oksj8fBD77ZHw4bkCPBA"
+    private val usdtContractAddress = "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"
+    private val baseUrl = "https://api.trongrid.io"
+
+    // A real wallet that received exactly 5 USDT-TRC20 (2026-07-11) and has NEVER had any native TRX/other
+    // on-chain activity - confirmed live to have no Account object at all (`/v1/accounts` returns `data: []`)
+    // despite genuinely holding the token (`balanceOf` correctly returns 5000000). Regression coverage for the
+    // exact bug this uncovered: fetchTrc20Balance used to read through `/v1/accounts` and silently returned 0
+    // for any address in this state, well after it was live and had already deceived a real user mid-transfer.
+    private val unactivatedHolderAddress = "TUdvwdGeqcag51XkhgRK21KmhH2qw37LZG"
+    private val unactivatedHolderExpectedUsdtBalance = BigInteger.valueOf(5_000_000L)
+
+    private val maxAmount = BigInteger.valueOf(10).pow(30)
+
+    private val tronGridApi = run {
+        val retrofit = Retrofit.Builder()
+            .client(OkHttpClient.Builder().build())
+            .baseUrl(baseUrl)
+            .addConverterFactory(ScalarsConverterFactory.create())
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+
+        RealTronGridApi(retrofit.create(RetrofitTronGridApi::class.java))
+    }
+
+    // TronGrid's public (no API key) endpoint rate-limits aggressively, and this test now runs on every PR
+    // (see balances_test.yml) in addition to its own 2 calls back-to-back - a bare 429 previously failed the
+    // whole run for a transient, infrastructure-level reason unrelated to whether the wallet's code is correct.
+    // Retry with backoff instead of just tolerating the flake.
+    private suspend fun <T> retryOn429(maxAttempts: Int = 4, block: suspend () -> T): T {
+        repeat(maxAttempts - 1) { attempt ->
+            try {
+                return block()
+            } catch (e: HttpException) {
+                if (e.code() != 429) throw e
+                delay(2_000L * (attempt + 1))
+            }
+        }
+        return block()
+    }
+
+    @Test
+    fun testNativeTrxBalanceLoading() = runBlocking {
+        val freeBalance = retryOn429 { tronGridApi.fetchNativeBalance(baseUrl, testAddress) }
+
+        assertTrue("TRX balance: $freeBalance is less than $maxAmount", maxAmount > freeBalance)
+        assertTrue("TRX balance: $freeBalance is greater than 0", BigInteger.ZERO < freeBalance)
+    }
+
+    @Test
+    fun testTrc20UsdtBalanceLoading() = runBlocking {
+        val freeBalance = retryOn429 { tronGridApi.fetchTrc20Balance(baseUrl, testAddress.tronAddressToAccountId(), usdtContractAddress) }
+
+        assertTrue("USDT-TRC20 balance: $freeBalance is less than $maxAmount", maxAmount > freeBalance)
+        assertTrue("USDT-TRC20 balance: $freeBalance is greater than 0", BigInteger.ZERO < freeBalance)
+    }
+
+    @Test
+    fun testTrc20BalanceLoadingForNeverActivatedHolder() = runBlocking {
+        val freeBalance = retryOn429 {
+            tronGridApi.fetchTrc20Balance(baseUrl, unactivatedHolderAddress.tronAddressToAccountId(), usdtContractAddress)
+        }
+
+        assertTrue(
+            "USDT-TRC20 balance for a never-activated holder: expected $unactivatedHolderExpectedUsdtBalance, got $freeBalance",
+            freeBalance == unactivatedHolderExpectedUsdtBalance
+        )
+    }
+}

build.gradle

@@ -1,7 +1,7 @@
 buildscript {
     ext {
         // App version
-        versionName = '1.1.1'
+        versionName = '1.1.2'
         versionCode = 1
 
         applicationId = "io.pezkuwichain.wallet"

common/src/main/java/io/novafoundation/nova/common/data/secrets/v2/MetaAccountSecrets.kt

@@ -28,6 +28,9 @@ object MetaAccountSecrets : Schema<MetaAccountSecrets>() {
 
     val TronKeypair by schema(KeyPairSchema).optional()
     val TronDerivationPath by string().optional()
+
+    val BitcoinKeypair by schema(KeyPairSchema).optional()
+    val BitcoinDerivationPath by string().optional()
 }
 
 object ChainAccountSecrets : Schema<ChainAccountSecrets>() {
@@ -47,6 +50,8 @@ fun MetaAccountSecrets(
     ethereumDerivationPath: String? = null,
     tronKeypair: Keypair? = null,
     tronDerivationPath: String? = null,
+    bitcoinKeypair: Keypair? = null,
+    bitcoinDerivationPath: String? = null,
 ): EncodableStruct<MetaAccountSecrets> = MetaAccountSecrets { secrets ->
     secrets[Entropy] = entropy
     secrets[SubstrateSeed] = substrateSeed
@@ -75,6 +80,15 @@ fun MetaAccountSecrets(
         }
     }
     secrets[TronDerivationPath] = tronDerivationPath
+
+    secrets[BitcoinKeypair] = bitcoinKeypair?.let {
+        KeyPairSchema { keypair ->
+            keypair[PublicKey] = it.publicKey
+            keypair[PrivateKey] = it.privateKey
+            keypair[Nonce] = null // bitcoin uses secp256k1 (like ethereum/tron), so nonce is always null
+        }
+    }
+    secrets[BitcoinDerivationPath] = bitcoinDerivationPath
 }
 
 fun ChainAccountSecrets(
@@ -103,6 +117,9 @@ val EncodableStruct<MetaAccountSecrets>.ethereumDerivationPath
 val EncodableStruct<MetaAccountSecrets>.tronDerivationPath
     get() = get(MetaAccountSecrets.TronDerivationPath)
 
+val EncodableStruct<MetaAccountSecrets>.bitcoinDerivationPath
+    get() = get(MetaAccountSecrets.BitcoinDerivationPath)
+
 val EncodableStruct<MetaAccountSecrets>.entropy
     get() = get(MetaAccountSecrets.Entropy)
 
@@ -118,6 +135,9 @@ val EncodableStruct<MetaAccountSecrets>.ethereumKeypair
 val EncodableStruct<MetaAccountSecrets>.tronKeypair
     get() = get(MetaAccountSecrets.TronKeypair)
 
+val EncodableStruct<MetaAccountSecrets>.bitcoinKeypair
+    get() = get(MetaAccountSecrets.BitcoinKeypair)
+
 val EncodableStruct<ChainAccountSecrets>.derivationPath
     get() = get(ChainAccountSecrets.DerivationPath)
 

common/src/main/java/io/novafoundation/nova/common/data/secrets/v2/SecretStoreV2.kt

@@ -156,20 +156,28 @@ val AccountSecrets.isChainAccountSecrets
 suspend fun SecretStoreV2.getMetaAccountKeypair(
     metaId: Long,
     isEthereum: Boolean,
+    isTron: Boolean = false,
+    isBitcoin: Boolean = false,
 ): Keypair = withContext(Dispatchers.Default) {
     val secrets = getMetaAccountSecrets(metaId) ?: noMetaSecrets(metaId)
 
-    mapMetaAccountSecretsToKeypair(secrets, isEthereum)
+    mapMetaAccountSecretsToKeypair(secrets, isEthereum, isTron, isBitcoin)
 }
 
 fun mapMetaAccountSecretsToKeypair(
     secrets: EncodableStruct<MetaAccountSecrets>,
     ethereum: Boolean,
+    tron: Boolean = false,
+    bitcoin: Boolean = false,
 ): Keypair {
-    val keypairStruct = if (ethereum) {
+    // Tron and Bitcoin both reuse Ethereum's secp256k1 curve but derive their own keypair under a different
-        secrets[MetaAccountSecrets.EthereumKeypair] ?: noEthereumSecret()
+    // SLIP-44 path - each must be checked before `ethereum`, not folded into it, or that account would get
-    } else {
+    // signed with the wrong (Ethereum) private key.
-        secrets[MetaAccountSecrets.SubstrateKeypair]
+    val keypairStruct = when {
+        tron -> secrets[MetaAccountSecrets.TronKeypair] ?: noTronSecret()
+        bitcoin -> secrets[MetaAccountSecrets.BitcoinKeypair] ?: noBitcoinSecret()
+        ethereum -> secrets[MetaAccountSecrets.EthereumKeypair] ?: noEthereumSecret()
+        else -> secrets[MetaAccountSecrets.SubstrateKeypair]
     }
 
     return mapKeypairStructToKeypair(keypairStruct)
@@ -178,8 +186,11 @@ fun mapMetaAccountSecretsToKeypair(
 fun mapMetaAccountSecretsToDerivationPath(
     secrets: EncodableStruct<MetaAccountSecrets>,
     ethereum: Boolean,
+    bitcoin: Boolean = false,
 ): String? {
-    return if (ethereum) {
+    return if (bitcoin) {
+        secrets[MetaAccountSecrets.BitcoinDerivationPath]
+    } else if (ethereum) {
         secrets[MetaAccountSecrets.EthereumDerivationPath]
     } else {
         secrets[MetaAccountSecrets.SubstrateDerivationPath]
@@ -198,6 +209,10 @@ private fun noChainSecrets(metaId: Long, accountId: ByteArray): Nothing {
 
 private fun noEthereumSecret(): Nothing = error("No ethereum keypair found")
 
+private fun noBitcoinSecret(): Nothing = error("No bitcoin keypair found")
+
+private fun noTronSecret(): Nothing = error("No tron keypair found")
+
 fun mapKeypairStructToKeypair(struct: EncodableStruct<KeyPairSchema>): Keypair {
     return Keypair(
         publicKey = struct[KeyPairSchema.PublicKey],

common/src/main/java/io/novafoundation/nova/common/utils/Bech32.kt

@@ -0,0 +1,164 @@
+package io.novafoundation.nova.common.utils
+
+/**
+ * Bech32 (BIP173) / Bech32m (BIP350) codec, hand-implemented since no such library is currently on this
+ * project's classpath (same rationale as [Base58]/[Base58Check] for Tron - this is a deterministic text
+ * encoding, not a secret-dependent cryptographic primitive).
+ *
+ * Direct port of the reference algorithm in BIP173/BIP350's `segwit_addr.py`. Cross-checked against BIP173's
+ * and BIP350's official test vectors - see [Bech32Test].
+ */
+object Bech32 {
+
+    private const val CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+    private const val BECH32_CONST = 1L
+    private const val BECH32M_CONST = 0x2bc830a3L
+
+    enum class Encoding(val const: Long) {
+        BECH32(BECH32_CONST),
+        BECH32M(BECH32M_CONST)
+    }
+
+    data class Decoded(val hrp: String, val values: IntArray, val encoding: Encoding)
+
+    private fun polymod(values: IntArray): Long {
+        val gen = longArrayOf(0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3)
+        var chk = 1L
+        for (v in values) {
+            val b = (chk ushr 25)
+            chk = (chk and 0x1ffffff) shl 5 xor v.toLong()
+            for (i in 0 until 5) {
+                if ((b ushr i) and 1L == 1L) {
+                    chk = chk xor gen[i]
+                }
+            }
+        }
+        return chk
+    }
+
+    private fun hrpExpand(hrp: String): IntArray {
+        val lower = hrp.map { (it.code ushr 5) }
+        val upper = hrp.map { (it.code and 31) }
+        return (lower + listOf(0) + upper).toIntArray()
+    }
+
+    private fun createChecksum(hrp: String, data: IntArray, encoding: Encoding): IntArray {
+        val values = hrpExpand(hrp) + data + IntArray(6)
+        val mod = polymod(values) xor encoding.const
+        return IntArray(6) { i -> ((mod ushr (5 * (5 - i))) and 31).toInt() }
+    }
+
+    fun encode(hrp: String, data: IntArray, encoding: Encoding): String {
+        val checksum = createChecksum(hrp, data, encoding)
+        val combined = data + checksum
+        return hrp + "1" + combined.map { CHARSET[it] }.joinToString("")
+    }
+
+    fun decode(input: String): Decoded {
+        require(input.length in 8..90) { "Bech32 string has invalid length: ${input.length}" }
+        require(input == input.lowercase() || input == input.uppercase()) { "Bech32 string is mixed case: $input" }
+
+        val lower = input.lowercase()
+        val separatorIndex = lower.lastIndexOf('1')
+        require(separatorIndex >= 1) { "Bech32 string is missing separator '1': $input" }
+        require(separatorIndex + 7 <= lower.length) { "Bech32 data part too short: $input" }
+
+        val hrp = lower.substring(0, separatorIndex)
+        val dataPart = lower.substring(separatorIndex + 1)
+
+        val values = IntArray(dataPart.length)
+        for ((i, c) in dataPart.withIndex()) {
+            val v = CHARSET.indexOf(c)
+            require(v >= 0) { "Invalid Bech32 character: '$c' in $input" }
+            values[i] = v
+        }
+
+        val checksumValue = polymod(hrpExpand(hrp) + values)
+        val encoding = when (checksumValue) {
+            BECH32_CONST -> Encoding.BECH32
+            BECH32M_CONST -> Encoding.BECH32M
+            else -> throw IllegalArgumentException("Invalid Bech32/Bech32m checksum: $input")
+        }
+
+        return Decoded(hrp, values.copyOfRange(0, values.size - 6), encoding)
+    }
+
+    /**
+     * Regroups bits between arbitrary group sizes (e.g. 8-bit bytes <-> 5-bit Bech32 words). Direct port of
+     * BIP173's `convertbits`.
+     */
+    fun convertBits(data: IntArray, fromBits: Int, toBits: Int, pad: Boolean): IntArray? {
+        var acc = 0
+        var bits = 0
+        val ret = mutableListOf<Int>()
+        val maxV = (1 shl toBits) - 1
+        val maxAcc = (1 shl (fromBits + toBits - 1)) - 1
+
+        for (value in data) {
+            if (value < 0 || (value ushr fromBits) != 0) return null
+
+            acc = ((acc shl fromBits) or value) and maxAcc
+            bits += fromBits
+            while (bits >= toBits) {
+                bits -= toBits
+                ret.add((acc ushr bits) and maxV)
+            }
+        }
+
+        if (pad) {
+            if (bits > 0) ret.add((acc shl (toBits - bits)) and maxV)
+        } else if (bits >= fromBits || ((acc shl (toBits - bits)) and maxV) != 0) {
+            return null
+        }
+
+        return ret.toIntArray()
+    }
+}
+
+/**
+ * Segwit address encoding/decoding (BIP173 witness v0, BIP350 witness v1+/Bech32m) on top of the raw [Bech32]
+ * codec above. Only witness version 0 (P2WPKH/P2WSH) is actually used by this app today (native SegWit only -
+ * Taproot/witness v1 is explicitly out of scope for now), but decode handles both since a user could paste any
+ * valid segwit address.
+ */
+object SegwitAddress {
+
+    fun encode(hrp: String, witnessVersion: Int, witnessProgram: ByteArray): String {
+        require(witnessVersion in 0..16) { "Invalid witness version: $witnessVersion" }
+        require(witnessProgram.size in 2..40) { "Invalid witness program length: ${witnessProgram.size}" }
+
+        val programWords = Bech32.convertBits(witnessProgram.map { it.toInt() and 0xff }.toIntArray(), 8, 5, true)
+            ?: throw IllegalArgumentException("Failed to convert witness program to 5-bit words")
+
+        val encoding = if (witnessVersion == 0) Bech32.Encoding.BECH32 else Bech32.Encoding.BECH32M
+
+        return Bech32.encode(hrp, intArrayOf(witnessVersion) + programWords, encoding)
+    }
+
+    data class Decoded(val witnessVersion: Int, val witnessProgram: ByteArray)
+
+    fun decode(expectedHrp: String, address: String): Decoded {
+        val (hrp, values, encoding) = Bech32.decode(address)
+        require(hrp == expectedHrp) { "Unexpected HRP: expected $expectedHrp, got $hrp" }
+        require(values.isNotEmpty()) { "Empty Bech32 data part: $address" }
+
+        val witnessVersion = values[0]
+        val expectedEncoding = if (witnessVersion == 0) Bech32.Encoding.BECH32 else Bech32.Encoding.BECH32M
+        require(encoding == expectedEncoding) {
+            "Witness version $witnessVersion requires ${expectedEncoding.name} but address used ${encoding.name}: $address"
+        }
+
+        val programWords = values.copyOfRange(1, values.size)
+        val programBytes = Bech32.convertBits(programWords, 5, 8, false)
+            ?: throw IllegalArgumentException("Invalid witness program padding: $address")
+
+        require(programBytes.size in 2..40) { "Invalid witness program length: $address" }
+        if (witnessVersion == 0) {
+            require(programBytes.size == 20 || programBytes.size == 32) {
+                "Witness v0 program must be 20 (P2WPKH) or 32 (P2WSH) bytes: $address"
+            }
+        }
+
+        return Decoded(witnessVersion, ByteArray(programBytes.size) { programBytes[it].toByte() })
+    }
+}

common/src/main/java/io/novafoundation/nova/common/utils/BitcoinAddress.kt

@@ -0,0 +1,56 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import org.bouncycastle.jcajce.provider.digest.RIPEMD160
+
+/**
+ * Native SegWit (P2WPKH) Bitcoin address support. Only witness v0 P2WPKH (`bc1q...`) is implemented - Taproot
+ * and legacy/P2SH-SegWit are explicitly out of scope for this phase (see the BTC integration plan).
+ *
+ * Bitcoin's "account id" here is the 20-byte HASH160 of the compressed secp256k1 public key - unlike
+ * Tron/Ethereum (which both derive their account id via keccak256 of the *uncompressed* pubkey), so this is
+ * NOT interchangeable with [tronPublicKeyToAccountId]/`asEthereumPublicKey().toAccountId()` despite all three
+ * using the same underlying secp256k1 keypair machinery.
+ */
+private const val BITCOIN_MAINNET_HRP = "bc"
+
+/** RIPEMD160(SHA256(x)) - the "HASH160" function used throughout Bitcoin for pubkey hashes and script hashes. */
+fun ByteArray.hash160(): ByteArray {
+    val ripemd160 = RIPEMD160.Digest()
+    return ripemd160.digest(this.sha256())
+}
+
+/**
+ * @param compressedPublicKey a 33-byte compressed secp256k1 public key (0x02/0x03 prefix + 32-byte x-coordinate).
+ */
+fun ByteArray.bitcoinPublicKeyToAccountId(): AccountId {
+    require(size == 33) { "Bitcoin native SegWit requires a compressed (33-byte) public key, got $size bytes" }
+
+    return hash160()
+}
+
+/** P2WPKH scriptPubKey: `OP_0 <20-byte-push> <hash160>`, i.e. `0x00 0x14 <20 bytes>`. */
+fun AccountId.toP2wpkhScriptPubKey(): ByteArray {
+    require(size == 20) { "Bitcoin account id (HASH160) must be 20 bytes, got $size" }
+
+    return byteArrayOf(0x00, 0x14) + this
+}
+
+fun AccountId.toBitcoinAddress(): String {
+    require(size == 20) { "Bitcoin account id (HASH160) must be 20 bytes, got $size" }
+
+    return SegwitAddress.encode(BITCOIN_MAINNET_HRP, witnessVersion = 0, witnessProgram = this)
+}
+
+fun String.bitcoinAddressToAccountId(): AccountId {
+    val decoded = SegwitAddress.decode(BITCOIN_MAINNET_HRP, this)
+    require(decoded.witnessVersion == 0 && decoded.witnessProgram.size == 20) {
+        "Not a native SegWit P2WPKH address: $this"
+    }
+
+    return decoded.witnessProgram
+}
+
+fun String.isValidBitcoinAddress(): Boolean = runCatching { bitcoinAddressToAccountId() }.isSuccess
+
+fun emptyBitcoinAccountId() = ByteArray(20) { 1 }

common/src/main/java/io/novafoundation/nova/common/utils/BitcoinDestinationAddress.kt

@@ -0,0 +1,79 @@
+package io.novafoundation.nova.common.utils
+
+private const val P2PKH_VERSION = 0x00
+private const val P2SH_VERSION = 0x05
+
+/**
+ * Any Bitcoin address this wallet can SEND to - a strict superset of what it can derive/receive as its own
+ * address (native SegWit only, see `BitcoinAddress.kt`). Needed because a real exchange withdrawal address was
+ * confirmed live to be P2SH (`3...`), which this app's original native-SegWit-only `isValidBitcoinAddress()`
+ * rejected outright, blocking the send with a misleading "QR can't be decoded" error (the QR was fine - a bare
+ * P2SH address - the address TYPE just wasn't recognized as a valid destination at all).
+ *
+ * Deliberately kept separate from [bitcoinAddressToAccountId]/[AccountId] - that function's 20-byte output feeds
+ * generic multi-chain code (`Chain.accountIdOf`) that assumes every account id is THIS wallet's own P2WPKH
+ * shape. Silently reusing it for a P2SH/P2PKH recipient would produce a 20-byte hash with no type tag, and
+ * downstream code would wrap it in the wrong (P2WPKH) scriptPubKey - sending funds to an address that doesn't
+ * match what was actually asked for. [BitcoinDestination] carries its type through to [toScriptPubKey] instead.
+ */
+sealed class BitcoinDestination {
+
+    data class NativeSegwit(val witnessProgram: ByteArray) : BitcoinDestination()
+
+    data class P2sh(val scriptHash: ByteArray) : BitcoinDestination()
+
+    data class P2pkh(val pubKeyHash: ByteArray) : BitcoinDestination()
+}
+
+fun String.decodeBitcoinDestination(): BitcoinDestination {
+    runCatching {
+        val decoded = SegwitAddress.decode("bc", this)
+        if (decoded.witnessVersion == 0 && decoded.witnessProgram.size == 20) {
+            return BitcoinDestination.NativeSegwit(decoded.witnessProgram)
+        }
+    }
+
+    // Base58Check itself is chain-agnostic (see TronAddress.kt) - a Bitcoin legacy address is 1 version byte +
+    // 20-byte hash, same shape as Tron's own address, just a different version byte and no fixed prefix meaning.
+    val decoded = Base58Check.decode(this)
+    require(decoded.size == 21) { "Not a valid Bitcoin legacy address: $this" }
+
+    val version = decoded[0].toInt() and 0xff
+    val hash = decoded.copyOfRange(1, decoded.size)
+
+    return when (version) {
+        P2PKH_VERSION -> BitcoinDestination.P2pkh(hash)
+        P2SH_VERSION -> BitcoinDestination.P2sh(hash)
+        else -> error("Unsupported Bitcoin address version byte: $version")
+    }
+}
+
+fun String.isValidBitcoinDestinationAddress(): Boolean = runCatching { decodeBitcoinDestination() }.isSuccess
+
+/**
+ * The raw 20-byte hash underlying any destination type, with its type tag dropped - safe ONLY for consumers
+ * that treat it as an opaque identicon/display seed (e.g. `Chain.accountIdOf` and, downstream, address icon
+ * generation) and never feed it back into [toScriptPubKey] or re-encode it as an address. Real transaction
+ * construction must keep using [decodeBitcoinDestination]/[toScriptPubKey] directly, which keep the type.
+ */
+val BitcoinDestination.hash: ByteArray
+    get() = when (this) {
+        is BitcoinDestination.NativeSegwit -> witnessProgram
+        is BitcoinDestination.P2sh -> scriptHash
+        is BitcoinDestination.P2pkh -> pubKeyHash
+    }
+
+/**
+ * @return the scriptPubKey a transaction output must use to actually pay this destination - P2SH/P2PKH have
+ * different script shapes from this wallet's own P2WPKH (see [toP2wpkhScriptPubKey]), despite all three being a
+ * "20-byte hash wrapped in a short script."
+ */
+fun BitcoinDestination.toScriptPubKey(): ByteArray = when (this) {
+    is BitcoinDestination.NativeSegwit -> byteArrayOf(0x00, 0x14) + witnessProgram
+
+    // OP_HASH160 <20-byte-push> OP_EQUAL
+    is BitcoinDestination.P2sh -> byteArrayOf(0xa9.toByte(), 0x14) + scriptHash + byteArrayOf(0x87.toByte())
+
+    // OP_DUP OP_HASH160 <20-byte-push> OP_EQUALVERIFY OP_CHECKSIG
+    is BitcoinDestination.P2pkh -> byteArrayOf(0x76, 0xa9.toByte(), 0x14) + pubKeyHash + byteArrayOf(0x88.toByte(), 0xac.toByte())
+}

common/src/main/java/io/novafoundation/nova/common/utils/BitcoinTransaction.kt

@@ -0,0 +1,170 @@
+package io.novafoundation.nova.common.utils
+
+import java.io.ByteArrayOutputStream
+
+/** SHA256(SHA256(x)) - Bitcoin's standard "double SHA256", used for both txids and the BIP143 sighash. */
+fun ByteArray.sha256d(): ByteArray = sha256().sha256()
+
+/** Bitcoin's variable-length integer ("CompactSize") encoding, used throughout raw transaction serialization. */
+fun Long.toBitcoinVarInt(): ByteArray {
+    require(this >= 0) { "VarInt cannot encode a negative value: $this" }
+    val out = ByteArrayOutputStream()
+    when {
+        this < 0xfd -> out.write(toInt())
+        this <= 0xffff -> {
+            out.write(0xfd)
+            out.write(toInt() and 0xff)
+            out.write((toInt() ushr 8) and 0xff)
+        }
+        this <= 0xffffffffL -> {
+            out.write(0xfe)
+            for (i in 0..3) out.write(((this ushr (8 * i)) and 0xff).toInt())
+        }
+        else -> {
+            out.write(0xff)
+            for (i in 0..7) out.write(((this ushr (8 * i)) and 0xff).toInt())
+        }
+    }
+    return out.toByteArray()
+}
+
+private fun Int.toLeBytes(byteCount: Int): ByteArray = ByteArray(byteCount) { i -> ((this ushr (8 * i)) and 0xff).toByte() }
+
+private fun Long.toLeBytes(byteCount: Int): ByteArray = ByteArray(byteCount) { i -> ((this ushr (8 * i)) and 0xff).toByte() }
+
+/**
+ * A single UTXO being spent, in the form needed to build and sign a transaction.
+ *
+ * @param txid the previous transaction's id in standard (RPC/explorer-display) byte order - this class reverses
+ * it internally to the on-wire/internal order raw transactions actually use (see [reversedTxid]).
+ */
+data class BitcoinInput(
+    val txid: ByteArray,
+    val vout: Int,
+    val valueSat: Long,
+    val sequence: Long = 0xfffffffdL, // RBF-signaling (BIP125), matching the exchange's proven, already-live choice
+) {
+    init {
+        require(txid.size == 32) { "txid must be 32 bytes, got ${txid.size}" }
+    }
+
+    fun reversedTxid(): ByteArray = txid.reversedArray()
+}
+
+data class BitcoinOutput(
+    val valueSat: Long,
+    val scriptPubKey: ByteArray,
+)
+
+/**
+ * Builds and signs native SegWit (P2WPKH-only) Bitcoin transactions using BIP143 sighashes - hand-implemented
+ * since no Bitcoin transaction library (bitcoinj/PSBT/etc.) is on this project's classpath (same rationale as
+ * [Bech32]/[DerSignature]). Verified byte-for-byte against BIP143's official "Native P2WPKH" worked example,
+ * including the fully serialized signed transaction - see [BitcoinTransactionTest].
+ */
+object BitcoinTransaction {
+
+    private const val SIGHASH_ALL = 1
+
+    /** P2PKH-shaped "scriptCode" BIP143 requires for a P2WPKH input - see BIP143's "Specification" section. */
+    private fun p2wpkhScriptCode(accountId: ByteArray): ByteArray {
+        require(accountId.size == 20)
+        val script = byteArrayOf(0x76.toByte(), 0xa9.toByte(), 0x14) + accountId + byteArrayOf(0x88.toByte(), 0xac.toByte())
+        return 25L.toBitcoinVarInt() + script
+    }
+
+    private fun serializeOutpoint(input: BitcoinInput): ByteArray = input.reversedTxid() + input.vout.toLeBytes(4)
+
+    private fun hashPrevouts(inputs: List<BitcoinInput>): ByteArray =
+        inputs.fold(ByteArray(0)) { acc, input -> acc + serializeOutpoint(input) }.sha256d()
+
+    private fun hashSequence(inputs: List<BitcoinInput>): ByteArray =
+        inputs.fold(ByteArray(0)) { acc, input -> acc + input.sequence.toLeBytes(4) }.sha256d()
+
+    private fun serializeOutput(output: BitcoinOutput): ByteArray =
+        output.valueSat.toLeBytes(8) + output.scriptPubKey.size.toLong().toBitcoinVarInt() + output.scriptPubKey
+
+    private fun hashOutputs(outputs: List<BitcoinOutput>): ByteArray =
+        outputs.fold(ByteArray(0)) { acc, output -> acc + serializeOutput(output) }.sha256d()
+
+    /**
+     * BIP143 sighash preimage + double-SHA256 for signing [inputIndex], which must be a P2WPKH input whose
+     * pubkey hashes to [signingAccountId]. Always uses SIGHASH_ALL, no ANYONECANPAY/NONE/SINGLE - this app never
+     * constructs those.
+     */
+    fun bip143Sighash(
+        version: Int,
+        inputs: List<BitcoinInput>,
+        outputs: List<BitcoinOutput>,
+        inputIndex: Int,
+        signingAccountId: ByteArray,
+        locktime: Int,
+    ): ByteArray {
+        val input = inputs[inputIndex]
+
+        val preimage = version.toLeBytes(4) +
+            hashPrevouts(inputs) +
+            hashSequence(inputs) +
+            serializeOutpoint(input) +
+            p2wpkhScriptCode(signingAccountId) +
+            input.valueSat.toLeBytes(8) +
+            input.sequence.toLeBytes(4) +
+            hashOutputs(outputs) +
+            locktime.toLeBytes(4) +
+            SIGHASH_ALL.toLeBytes(4)
+
+        return preimage.sha256d()
+    }
+
+    /**
+     * @param witnesses one (derSignatureWithoutSighashByte, compressedPublicKey) pair per input, in input order -
+     * every input in this app's transactions is a P2WPKH input from this wallet's own single address, so every
+     * witness has exactly 2 items (signature, pubkey), never a bare key-path/script-path Taproot witness or a
+     * multisig-style stack.
+     */
+    fun serializeSigned(
+        version: Int,
+        inputs: List<BitcoinInput>,
+        outputs: List<BitcoinOutput>,
+        witnesses: List<Pair<ByteArray, ByteArray>>,
+        locktime: Int,
+    ): ByteArray {
+        require(witnesses.size == inputs.size) { "Need exactly one witness per input" }
+
+        val out = ByteArrayOutputStream()
+        out.write(version.toLeBytes(4))
+        out.write(0x00) // segwit marker
+        out.write(0x01) // segwit flag
+        out.write(inputs.size.toLong().toBitcoinVarInt())
+        for (input in inputs) {
+            out.write(input.reversedTxid())
+            out.write(input.vout.toLeBytes(4))
+            out.write(0L.toBitcoinVarInt()) // scriptSig: empty for a native SegWit input
+            out.write(input.sequence.toLeBytes(4))
+        }
+        out.write(outputs.size.toLong().toBitcoinVarInt())
+        for (output in outputs) {
+            out.write(serializeOutput(output))
+        }
+        for ((derSignature, publicKey) in witnesses) {
+            out.write(2L.toBitcoinVarInt()) // 2 witness items: signature, pubkey
+            val sigWithHashType = derSignature + byteArrayOf(SIGHASH_ALL.toByte())
+            out.write(sigWithHashType.size.toLong().toBitcoinVarInt())
+            out.write(sigWithHashType)
+            out.write(publicKey.size.toLong().toBitcoinVarInt())
+            out.write(publicKey)
+        }
+        out.write(locktime.toLeBytes(4))
+
+        return out.toByteArray()
+    }
+
+    /**
+     * Estimated virtual size in vbytes for fee purposes - the same hardcoded heuristic already proven in
+     * production by `pezkuwi-exchange/wallet-service` (`inputs*68 + outputs*31 + 11`), reused here rather than
+     * computing an exact post-signing weight (which would require knowing final DER signature lengths ahead of
+     * time - low-S-normalized DER signatures are 70-72 bytes almost always, making this heuristic accurate to
+     * within a few vbytes in practice).
+     */
+    fun estimateVsize(inputCount: Int, outputCount: Int): Long = inputCount * 68L + outputCount * 31L + 11L
+}

common/src/main/java/io/novafoundation/nova/common/utils/DerSignature.kt

@@ -0,0 +1,62 @@
+package io.novafoundation.nova.common.utils
+
+import java.math.BigInteger
+
+/**
+ * DER-encodes a raw secp256k1 ECDSA (r, s) signature the way Bitcoin's script/witness format requires it -
+ * unlike Tron/Ethereum, which both use a fixed-size compact r(32)+s(32)+v(1) format (see
+ * [io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.RealTronTransactionService]'s
+ * doc-comment for that format), Bitcoin signatures are a variable-length ASN.1 DER `SEQUENCE(INTEGER r, INTEGER
+ * s)`.
+ *
+ * `r`/`s` are taken as raw big-endian unsigned 32-byte values - exactly what
+ * [io.novasama.substrate_sdk_android]'s `SignatureWrapper.Ecdsa` (reached via `SignedRaw.toEcdsaSignatureData()`)
+ * already exposes for Ethereum-style signing, which this app already uses. No new signing call path is needed
+ * for Bitcoin: only this pure, standalone encoding step is new.
+ */
+object DerSignature {
+
+    // secp256k1 curve order n, and n/2 - Bitcoin Core's standardness rules (BIP62) reject a signature whose `s`
+    // is greater than n/2 ("high-S"); wallets are expected to always produce the "low-S" of the two equally
+    // valid (r, s) and (r, n-s) signatures for a given message, or relay nodes/miners may refuse the transaction.
+    private val CURVE_ORDER = BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 16)
+    private val HALF_CURVE_ORDER = CURVE_ORDER.shiftRight(1)
+
+    /**
+     * @param r raw big-endian unsigned 32-byte value
+     * @param s raw big-endian unsigned 32-byte value (will be normalized to low-S if not already)
+     * @return DER-encoded `SEQUENCE(INTEGER r, INTEGER s)`, WITHOUT the trailing sighash-type byte (the caller
+     * appends that when assembling the witness/scriptSig, since it is not part of the DER signature itself).
+     */
+    fun encode(r: ByteArray, s: ByteArray): ByteArray {
+        val rInt = BigInteger(1, r)
+        var sInt = BigInteger(1, s)
+
+        if (sInt > HALF_CURVE_ORDER) {
+            sInt = CURVE_ORDER.subtract(sInt)
+        }
+
+        val rEncoded = encodeInteger(rInt)
+        val sEncoded = encodeInteger(sInt)
+
+        val sequenceBody = rEncoded + sEncoded
+
+        return byteArrayOf(0x30, sequenceBody.size.toDerLength()) + sequenceBody
+    }
+
+    /**
+     * ASN.1 DER INTEGER: tag(0x02) + length + minimal big-endian two's-complement bytes. [BigInteger.toByteArray]
+     * already produces minimal big-endian two's-complement (including the leading 0x00 disambiguation byte when
+     * the high bit of the first byte would otherwise be set, which would make it read as negative) - since
+     * `rInt`/`sInt` are always non-negative here, its output is exactly the DER INTEGER content we need.
+     */
+    private fun encodeInteger(value: BigInteger): ByteArray {
+        val bytes = value.toByteArray()
+        return byteArrayOf(0x02, bytes.size.toDerLength()) + bytes
+    }
+
+    private fun Int.toDerLength(): Byte {
+        require(this in 0..127) { "DER length $this requires long-form encoding, not expected for a 32-byte ECDSA signature" }
+        return toByte()
+    }
+}

common/src/main/java/io/novafoundation/nova/common/utils/TronAddress.kt

@@ -2,6 +2,7 @@ package io.novafoundation.nova.common.utils
 
 import io.novasama.substrate_sdk_android.extensions.asEthereumPublicKey
 import io.novasama.substrate_sdk_android.extensions.toAccountId
+import io.novasama.substrate_sdk_android.extensions.toHexString
 import io.novasama.substrate_sdk_android.runtime.AccountId
 import java.math.BigInteger
 
@@ -113,3 +114,21 @@ fun String.tronAddressToAccountId(): AccountId {
 fun String.isValidTronAddress(): Boolean = runCatching { tronAddressToAccountId() }.isSuccess
 
 fun emptyTronAccountId() = ByteArray(20) { 1 }
+
+/**
+ * Hex form of a Tron address (`0x41` prefix byte ++ accountId, hex-encoded, no `0x` prefix), e.g.
+ * `41a614f803b6fd780986a42c78ec9c7f77e6ded13c`. This is the format TronGrid's `/wallet/` transaction
+ * construction/broadcast endpoints expect when called with `"visible": false` (as opposed to the human-facing
+ * Base58Check form used by the `/v1/accounts/{address}` balance endpoint and by [toTronAddress]).
+ */
+fun AccountId.toTronHexAddress(): String {
+    require(size == 20) { "Tron account id must be 20 bytes, got $size" }
+
+    return byteArrayOf(TRON_ADDRESS_PREFIX_BYTE).toHexString(withPrefix = false) + toHexString(withPrefix = false)
+}
+
+/**
+ * Converts a human-facing Base58Check Tron address (e.g. a TRC20 `contractAddress` from chain config) directly
+ * into the hex form described in [toTronHexAddress].
+ */
+fun String.tronAddressToHexAddress(): String = tronAddressToAccountId().toTronHexAddress()

common/src/main/res/values/strings.xml

@@ -355,6 +355,8 @@
 
     <!-- Bridge Screen -->
     <string name="bridge_title">DOT ↔ HEZ Bridge</string>
+    <string name="bridge_pair_dot_hez">HEZ ⇄ DOT</string>
+    <string name="bridge_pair_usdt">USDT ⇄ USDT.p</string>
     <string name="bridge_you_send">You send</string>
     <string name="bridge_you_receive">You receive (estimated)</string>
     <string name="bridge_exchange_rate">Exchange rate</string>

common/src/test/java/io/novafoundation/nova/common/utils/Bech32Test.kt

@@ -0,0 +1,179 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertThrows
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * All test vectors below are quoted verbatim from the official BIPs (fetched directly from
+ * https://github.com/bitcoin/bips at implementation time), not invented for this test:
+ * - BIP173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki) for Bech32 checksum vectors.
+ * - BIP350 (https://github.com/bitcoin/bips/blob/master/bip-0350.mediawiki) for Bech32m checksum vectors
+ *   and the current (BIP350-superseding-BIP173) segwit address <-> scriptPubKey vectors - BIP173's own
+ *   witness-v1+ vectors used plain Bech32 (since Bech32m didn't exist yet) and are now considered INVALID;
+ *   only BIP173's witness-v0 vectors still apply unchanged under BIP350.
+ */
+class Bech32Test {
+
+    @Test
+    fun `valid Bech32 checksums should decode without throwing`() {
+        val validBech32 = listOf(
+            "A12UEL5L",
+            "a12uel5l",
+            "an83characterlonghumanreadablepartthatcontainsthenumber1andtheexcludedcharactersbio1tt5tgs",
+            "abcdef1qpzry9x8gf2tvdw0s3jn54khce6mua7lmqqqxw",
+            "11qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqc8247j",
+            "split1checkupstagehandshakeupstreamerranterredcaperred2y9e3w",
+            "?1ezyfcl"
+        )
+
+        for (address in validBech32) {
+            val decoded = Bech32.decode(address)
+            assertEquals("$address should decode as Bech32 (not Bech32m)", Bech32.Encoding.BECH32, decoded.encoding)
+        }
+    }
+
+    @Test
+    fun `valid Bech32m checksums should decode without throwing`() {
+        val validBech32m = listOf(
+            "A1LQFN3A",
+            "a1lqfn3a",
+            "an83characterlonghumanreadablepartthatcontainsthetheexcludedcharactersbioandnumber11sg7hg6",
+            "abcdef1l7aum6echk45nj3s0wdvt2fg8x9yrzpqzd3ryx",
+            "11llllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllludsr8",
+            "split1checkupstagehandshakeupstreamerranterredcaperredlc445v",
+            "?1v759aa"
+        )
+
+        for (address in validBech32m) {
+            val decoded = Bech32.decode(address)
+            assertEquals("$address should decode as Bech32m (not Bech32)", Bech32.Encoding.BECH32M, decoded.encoding)
+        }
+    }
+
+    @Test
+    fun `mixed case Bech32 string should be rejected`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            Bech32.decode("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sL5k7")
+        }
+    }
+
+    // --- Segwit address <-> scriptPubKey (BIP350's updated table) ---
+
+    private fun expectedWitnessVersionAndProgram(scriptPubKeyHex: String): Pair<Int, ByteArray> {
+        val script = scriptPubKeyHex.fromHex()
+        val versionByte = script[0].toInt() and 0xff
+        val witnessVersion = if (versionByte == 0) 0 else versionByte - 0x50
+        val programLength = script[1].toInt() and 0xff
+        val program = script.copyOfRange(2, 2 + programLength)
+        return witnessVersion to program
+    }
+
+    @Test
+    fun `known mainnet P2WPKH address should decode to the documented scriptPubKey`() {
+        val address = "BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4"
+        val (expectedVersion, expectedProgram) = expectedWitnessVersionAndProgram("0014751e76e8199196d454941c45d1b3a323f1433bd6")
+
+        val decoded = SegwitAddress.decode("bc", address)
+
+        assertEquals(expectedVersion, decoded.witnessVersion)
+        assertTrue(decoded.witnessProgram.contentEquals(expectedProgram))
+    }
+
+    @Test
+    fun `known testnet P2WSH address should decode to the documented scriptPubKey`() {
+        val address = "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7"
+        val (expectedVersion, expectedProgram) =
+            expectedWitnessVersionAndProgram("00201863143c14c5166804bd19203356da136c985678cd4d27a1b8c6329604903262")
+
+        val decoded = SegwitAddress.decode("tb", address)
+
+        assertEquals(expectedVersion, decoded.witnessVersion)
+        assertTrue(decoded.witnessProgram.contentEquals(expectedProgram))
+    }
+
+    @Test
+    fun `known testnet P2WPKH address (all-zero-ish program) should decode correctly`() {
+        val address = "tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy"
+        val (expectedVersion, expectedProgram) =
+            expectedWitnessVersionAndProgram("0020000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433")
+
+        val decoded = SegwitAddress.decode("tb", address)
+
+        assertEquals(expectedVersion, decoded.witnessVersion)
+        assertTrue(decoded.witnessProgram.contentEquals(expectedProgram))
+    }
+
+    @Test
+    fun `known witness v1 taproot-style address (Bech32m) should decode correctly`() {
+        val address = "bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y"
+        val (expectedVersion, expectedProgram) = expectedWitnessVersionAndProgram(
+            "5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6"
+        )
+
+        val decoded = SegwitAddress.decode("bc", address)
+
+        assertEquals(1, expectedVersion)
+        assertEquals(expectedVersion, decoded.witnessVersion)
+        assertTrue(decoded.witnessProgram.contentEquals(expectedProgram))
+    }
+
+    @Test
+    fun `P2WPKH encode should reproduce the exact known mainnet address (lowercase)`() {
+        val (_, program) = expectedWitnessVersionAndProgram("0014751e76e8199196d454941c45d1b3a323f1433bd6")
+
+        val encoded = SegwitAddress.encode("bc", witnessVersion = 0, witnessProgram = program)
+
+        assertEquals("BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4".lowercase(), encoded)
+    }
+
+    @Test
+    fun `encode-decode should round trip for a fresh 20-byte P2WPKH program`() {
+        val program = "0011223344556677889900112233445566778899".fromHex()
+        assertEquals(20, program.size)
+
+        val address = SegwitAddress.encode("bc", witnessVersion = 0, witnessProgram = program)
+        val decoded = SegwitAddress.decode("bc", address)
+
+        assertEquals(0, decoded.witnessVersion)
+        assertTrue(decoded.witnessProgram.contentEquals(program))
+    }
+
+    @Test
+    fun `invalid checksum should be rejected`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            SegwitAddress.decode("bc", "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5")
+        }
+    }
+
+    @Test
+    fun `wrong hrp should be rejected`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            SegwitAddress.decode("bc", "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7")
+        }
+    }
+
+    @Test
+    fun `invalid program length should be rejected`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            SegwitAddress.decode("bc", "bc1rw5uspcuh")
+        }
+    }
+
+    @Test
+    fun `witness v0 with wrong program length per BIP141 should be rejected`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            SegwitAddress.decode("bc", "BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P")
+        }
+    }
+
+    @Test
+    fun `witness v0 encoded with Bech32m instead of Bech32 should be rejected (BIP350)`() {
+        assertThrows(IllegalArgumentException::class.java) {
+            SegwitAddress.decode("bc", "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kemeawh")
+        }
+    }
+}

common/src/test/java/io/novafoundation/nova/common/utils/BitcoinAddressTest.kt

@@ -0,0 +1,98 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * [knownAccountId]/[knownAddress] is BIP173/BIP350's official segwit address test vector
+ * (BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4 <-> scriptPubKey 0014751e76e8199196d454941c45d1b3a323f1433bd6,
+ * fetched directly from https://github.com/bitcoin/bips at implementation time) - an independently-verifiable,
+ * real-world test vector, not invented for this test. [knownPublicKey] is BIP143's official Native P2WPKH
+ * example pubkey, whose HASH160 is independently confirmed (via Bech32AddressTest and BitcoinTransactionTest)
+ * to equal a *different* known account id - used here only to test [hash160]/[bitcoinPublicKeyToAccountId] in
+ * isolation from address encoding.
+ */
+class BitcoinAddressTest {
+
+    private val knownAccountId = "751e76e8199196d454941c45d1b3a323f1433bd6".fromHex()
+    private val knownAddress = "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4"
+
+    private val knownPublicKey = "025476c2e83188368da1ff3e292e7acafcdb3566bb0ad253f62fc70f07aeee6357".fromHex()
+    private val knownPublicKeyAccountId = "1d0f172a0ecb48aee1be1f2687d2963ae33f71a1".fromHex()
+
+    @Test
+    fun `accountId to address should produce the known BIP173 address`() {
+        assertEquals(knownAddress, knownAccountId.toBitcoinAddress())
+    }
+
+    @Test
+    fun `address to accountId should decode the known BIP173 address back to the known bytes`() {
+        assertTrue(knownAddress.bitcoinAddressToAccountId().contentEquals(knownAccountId))
+    }
+
+    @Test
+    fun `accountId to address and back should round trip`() {
+        val decodedBack = knownAccountId.toBitcoinAddress().bitcoinAddressToAccountId()
+        assertTrue(decodedBack.contentEquals(knownAccountId))
+    }
+
+    @Test
+    fun `compressed public key to accountId should match the known BIP143 hash160`() {
+        assertTrue(knownPublicKey.bitcoinPublicKeyToAccountId().contentEquals(knownPublicKeyAccountId))
+    }
+
+    @Test
+    fun `uncompressed (65-byte) public key should be rejected`() {
+        val uncompressed = ByteArray(65)
+        try {
+            uncompressed.bitcoinPublicKeyToAccountId()
+            org.junit.Assert.fail("Expected an IllegalArgumentException for a non-33-byte public key")
+        } catch (e: IllegalArgumentException) {
+            // expected
+        }
+    }
+
+    @Test
+    fun `toP2wpkhScriptCode should produce OP_0 push-20 the account id`() {
+        val scriptPubKey = knownAccountId.toP2wpkhScriptPubKey()
+
+        assertEquals("0014751e76e8199196d454941c45d1b3a323f1433bd6", scriptPubKey.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `isValidBitcoinAddress should accept the known good address`() {
+        assertTrue(knownAddress.isValidBitcoinAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinAddress should reject a corrupted checksum`() {
+        val corrupted = "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5"
+        assertFalse(corrupted.isValidBitcoinAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinAddress should reject a testnet address`() {
+        assertFalse("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7".isValidBitcoinAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinAddress should reject a Tron address`() {
+        assertFalse("TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t".isValidBitcoinAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinAddress should reject a P2WSH (32-byte program) address as not P2WPKH`() {
+        assertFalse("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y".isValidBitcoinAddress())
+    }
+
+    @Test
+    fun `hash160 known test vector should match independently-verified value`() {
+        // hash160("hello") independently cross-checked via Python's hashlib (ripemd160(sha256(b"hello"))) at
+        // implementation time - a different library from this project's BouncyCastle, not just self-consistency.
+        assertEquals("b6a9c8c230722b7c748331a8b450f05566dc7d0f", "hello".toByteArray().hash160().toHexString(withPrefix = false))
+    }
+}

common/src/test/java/io/novafoundation/nova/common/utils/BitcoinDestinationAddressTest.kt

@@ -0,0 +1,99 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Test vectors:
+ * - [genesisP2pkhAddress] is Satoshi's genesis coinbase address - real, independently-verifiable, its hash160
+ *   cross-checked via Python's hashlib/base58 at implementation time.
+ * - [okxWithdrawalAddress] is a real address confirmed live: an OKX BTC withdrawal QR, whose bare (non-BIP21)
+ *   content this app's original native-SegWit-only address validation rejected outright, producing a misleading
+ *   "QR can't be decoded" error - the actual bug this file's code fixes.
+ */
+class BitcoinDestinationAddressTest {
+
+    private val genesisP2pkhAddress = "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"
+    private val genesisP2pkhHash160 = "62e907b15cbf27d5425399ebf6f0fb50ebb88f18"
+
+    private val piVanityP2shAddress = "3P14159f73E4gFr7JterCCQh9QjiTjiZrG"
+
+    private val okxWithdrawalAddress = "3QBsCZAv5hsZSrDpTcQYEqd82TdA8Qr3g9"
+    private val okxWithdrawalHash160 = "f6c78c3a049bfa34ed05b22ca9515414cdcb46d1"
+
+    private val nativeSegwitAddress = "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4"
+    private val nativeSegwitAccountId = "751e76e8199196d454941c45d1b3a323f1433bd6"
+
+    @Test
+    fun `should decode a known P2PKH address to the correct hash160`() {
+        val destination = genesisP2pkhAddress.decodeBitcoinDestination()
+
+        assertTrue(destination is BitcoinDestination.P2pkh)
+        assertEquals(genesisP2pkhHash160, (destination as BitcoinDestination.P2pkh).pubKeyHash.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `should decode a known P2SH address to a P2sh destination`() {
+        val destination = piVanityP2shAddress.decodeBitcoinDestination()
+
+        assertTrue(destination is BitcoinDestination.P2sh)
+    }
+
+    @Test
+    fun `should decode the real OKX withdrawal address to the correct P2SH hash160`() {
+        val destination = okxWithdrawalAddress.decodeBitcoinDestination()
+
+        assertTrue(destination is BitcoinDestination.P2sh)
+        assertEquals(okxWithdrawalHash160, (destination as BitcoinDestination.P2sh).scriptHash.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `should still decode a native segwit address as NativeSegwit`() {
+        val destination = nativeSegwitAddress.decodeBitcoinDestination()
+
+        assertTrue(destination is BitcoinDestination.NativeSegwit)
+        assertEquals(nativeSegwitAccountId, (destination as BitcoinDestination.NativeSegwit).witnessProgram.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `isValidBitcoinDestinationAddress should accept P2PKH, P2SH and native segwit`() {
+        assertTrue(genesisP2pkhAddress.isValidBitcoinDestinationAddress())
+        assertTrue(piVanityP2shAddress.isValidBitcoinDestinationAddress())
+        assertTrue(okxWithdrawalAddress.isValidBitcoinDestinationAddress())
+        assertTrue(nativeSegwitAddress.isValidBitcoinDestinationAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinDestinationAddress should reject a corrupted checksum`() {
+        assertFalse("1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNb".isValidBitcoinDestinationAddress())
+    }
+
+    @Test
+    fun `isValidBitcoinDestinationAddress should reject a Tron address`() {
+        assertFalse("TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t".isValidBitcoinDestinationAddress())
+    }
+
+    @Test
+    fun `P2SH destination should produce OP_HASH160 push-20 OP_EQUAL scriptPubKey`() {
+        val destination = okxWithdrawalAddress.decodeBitcoinDestination()
+
+        assertEquals("a914${okxWithdrawalHash160}87", destination.toScriptPubKey().toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `P2PKH destination should produce OP_DUP OP_HASH160 push-20 OP_EQUALVERIFY OP_CHECKSIG scriptPubKey`() {
+        val destination = genesisP2pkhAddress.decodeBitcoinDestination()
+
+        assertEquals("76a914${genesisP2pkhHash160}88ac", destination.toScriptPubKey().toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `NativeSegwit destination should produce OP_0 push-20 scriptPubKey`() {
+        val destination = nativeSegwitAddress.decodeBitcoinDestination()
+
+        assertEquals("0014$nativeSegwitAccountId", destination.toScriptPubKey().toHexString(withPrefix = false))
+    }
+}

common/src/test/java/io/novafoundation/nova/common/utils/BitcoinTransactionTest.kt

@@ -0,0 +1,92 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+/**
+ * Verified byte-for-byte against BIP143's official "Native P2WPKH" worked example
+ * (https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki, fetched directly at implementation time) -
+ * every intermediate value below (hashPrevouts/hashSequence/hashOutputs/preimage/sighash/signed tx) is quoted
+ * verbatim from that document, not invented for this test.
+ *
+ * The two inputs' txids are given here in the conventional *display* order (reversed from on-wire order) - the
+ * same order a REST API like mempool.space returns - to exercise [BitcoinInput.reversedTxid]'s reversal for
+ * real, rather than pre-reversing them and bypassing that logic.
+ */
+class BitcoinTransactionTest {
+
+    // BIP143 doc's wire-order txids, reversed here once (by hand, offline) to get the display-order string a
+    // real API would hand back - see this test class's doc comment.
+    private val input0Txid = "9f96ade4b41d5433f4eda31e1738ec2b36f6e7d1420d94a6af99801a88f7f7ff".fromHex()
+    private val input1Txid = "8ac60eb9575db5b2d987e29f301b5b819ea83a5c6579d282d189cc04b8e151ef".fromHex()
+
+    // sequence is the *value* that gets LE-encoded, NOT the wire bytes - the doc shows input 0's on-wire
+    // sequence bytes as "eeffffff", which as a little-endian integer is 0xffffffee, not 0xeeffffff (a
+    // transcription of this exact off-by-reversal was caught by a failing CI run before this fix).
+    private val input0 = BitcoinInput(txid = input0Txid, vout = 0, valueSat = 625_000_000L, sequence = 0xffffffeeL)
+    private val input1 = BitcoinInput(txid = input1Txid, vout = 1, valueSat = 600_000_000L, sequence = 0xffffffffL)
+
+    private val output0 = BitcoinOutput(
+        valueSat = 112_340_000L,
+        scriptPubKey = "76a9148280b37df378db99f66f85c95a783a76ac7a6d5988ac".fromHex()
+    )
+    private val output1 = BitcoinOutput(
+        valueSat = 223_450_000L,
+        scriptPubKey = "76a9143bde42dbee7e4dbe6a21b2d50ce2f0167faa815988ac".fromHex()
+    )
+
+    private val signingAccountId = "1d0f172a0ecb48aee1be1f2687d2963ae33f71a1".fromHex()
+    private val publicKey = "025476c2e83188368da1ff3e292e7acafcdb3566bb0ad253f62fc70f07aeee6357".fromHex()
+
+    @Test
+    fun `hash160 of the known public key should match the known account id`() {
+        assertEquals(signingAccountId.toHexString(withPrefix = false), publicKey.hash160().toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `bip143Sighash should match the known sighash for signing input 1`() {
+        val sighash = BitcoinTransaction.bip143Sighash(
+            version = 1,
+            inputs = listOf(input0, input1),
+            outputs = listOf(output0, output1),
+            inputIndex = 1,
+            signingAccountId = signingAccountId,
+            locktime = 0x11,
+        )
+
+        assertEquals("c37af31116d1b27caf68aae9e3ac82f1477929014d5b917657d0eb49478cb670", sighash.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `serializeSigned should produce the exact expected bytes for a single-input all-P2WPKH transaction`() {
+        // Hand-verified (not from a BIP143 vector, since BIP143's own worked example mixes a legacy P2PK input
+        // with the P2WPKH one - this app only ever builds all-P2WPKH transactions since it only ever spends
+        // from its own single P2WPKH address). Expected hex was independently computed byte-by-byte from this
+        // function's own documented format (version/marker/flag/varints/witness) rather than copied from here.
+        val txidWire = "0a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f9".fromHex()
+        val txidDisplay = txidWire.reversedArray() // what a mempool.space-style API would actually return
+
+        val input = BitcoinInput(txid = txidDisplay, vout = 3, valueSat = 100_000L, sequence = 0xfffffffdL)
+        val output = BitcoinOutput(valueSat = 90_000L, scriptPubKey = "0014".fromHex() + "2222222222222222222222222222222222222222".fromHex())
+        val derSignature = "3006020101020101".fromHex()
+        val dummyPubKey = "0246e14bb0d93c0d64c265dd6b0eeeba6b9bd94aa88ce74aa302cf1cb8fdff9b6a".fromHex()
+
+        val signed = BitcoinTransaction.serializeSigned(
+            version = 2,
+            inputs = listOf(input),
+            outputs = listOf(output),
+            witnesses = listOf(derSignature to dummyPubKey),
+            locktime = 0,
+        )
+
+        val expected = "020000000001010a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90300000000fdffffff01905f01000000000016001422222222222222222222222222222222222222220209300602010102010101210246e14bb0d93c0d64c265dd6b0eeeba6b9bd94aa88ce74aa302cf1cb8fdff9b6a00000000"
+        assertEquals(expected, signed.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `estimateVsize should match the exchange's proven heuristic formula`() {
+        assertEquals(1 * 68L + 2 * 31L + 11L, BitcoinTransaction.estimateVsize(inputCount = 1, outputCount = 2))
+    }
+}

common/src/test/java/io/novafoundation/nova/common/utils/DerSignatureTest.kt

@@ -0,0 +1,72 @@
+package io.novafoundation.nova.common.utils
+
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import java.math.BigInteger
+
+class DerSignatureTest {
+
+    private val curveOrder = BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 16)
+
+    private fun ByteArray.pad32() = ByteArray(32 - size) + this
+
+    @Test
+    fun `small r and high-bit s should each get a leading zero byte per DER minimal-integer rule`() {
+        // r = 1 (0x01, high bit clear -> no padding needed), s = 128 (0x80, high bit set -> needs 0x00 prefix
+        // so it isn't misread as a negative two's-complement integer). Manually verified expected DER bytes.
+        val r = BigInteger.valueOf(1).toByteArray().pad32()
+        val s = BigInteger.valueOf(128).toByteArray().pad32() // 128 < half-curve-order, so no low-S flip happens
+
+        val der = DerSignature.encode(r, s)
+
+        assertEquals("30070201010202" + "0080", der.toHexString(withPrefix = false))
+    }
+
+    @Test
+    fun `high-S signature should be normalized to low-S per BIP62`() {
+        val r = BigInteger.valueOf(42).toByteArray().pad32()
+        val highS = curveOrder.subtract(BigInteger.ONE) // curveOrder - 1: definitely > halfCurveOrder
+        val s = highS.toByteArray().let { if (it.size > 32) it.copyOfRange(it.size - 32, it.size) else it }.pad32()
+
+        val der = DerSignature.encode(r, s)
+
+        // Expect the DER-encoded s to equal curveOrder - highS == 1, not the original high-S value.
+        val expectedNormalizedS = curveOrder.subtract(highS)
+        assertEquals(BigInteger.ONE, expectedNormalizedS)
+
+        // Extract the s component back out of the DER bytes to check it against the expected normalized value.
+        val rLen = der[3].toInt()
+        val sTagIndex = 4 + rLen
+        val sLen = der[sTagIndex + 1].toInt()
+        val sBytes = der.copyOfRange(sTagIndex + 2, sTagIndex + 2 + sLen)
+        assertEquals(expectedNormalizedS, BigInteger(1, sBytes))
+    }
+
+    @Test
+    fun `already-low-S signature should be left unchanged`() {
+        val r = BigInteger.valueOf(7).toByteArray().pad32()
+        val lowS = BigInteger.valueOf(12345)
+        val s = lowS.toByteArray().pad32()
+
+        val der = DerSignature.encode(r, s)
+
+        val rLen = der[3].toInt()
+        val sTagIndex = 4 + rLen
+        val sLen = der[sTagIndex + 1].toInt()
+        val sBytes = der.copyOfRange(sTagIndex + 2, sTagIndex + 2 + sLen)
+        assertEquals(lowS, BigInteger(1, sBytes))
+    }
+
+    @Test
+    fun `DER output should start with SEQUENCE tag and correct overall length`() {
+        val r = "0011223344556677889900112233445566778899aabbccddeeff0011223344".fromHex()
+        val s = "1122334455667788990011223344556677889900112233445566778899aabb".fromHex()
+
+        val der = DerSignature.encode(r, s)
+
+        assertEquals(0x30.toByte(), der[0])
+        assertEquals(der.size - 2, der[1].toInt())
+    }
+}

common/src/test/java/io/novafoundation/nova/common/utils/TronAddressTest.kt

@@ -44,6 +44,18 @@ class TronAddressTest {
         assertTrue(decodedBack.contentEquals(accountId))
     }
 
+    @Test
+    fun `toTronHexAddress should produce the known hex form`() {
+        val accountId = knownTronAddressHex.fromHex().copyOfRange(1, 21)
+
+        assertEquals(knownTronAddressHex, accountId.toTronHexAddress())
+    }
+
+    @Test
+    fun `tronAddressToHexAddress should produce the known hex form directly from a Base58 address`() {
+        assertEquals(knownTronAddressHex, knownTronAddress.tronAddressToHexAddress())
+    }
+
     @Test
     fun `isValidTronAddress should accept known good address`() {
         assertTrue(knownTronAddress.isValidTronAddress())

core-db/src/androidTest/java/io/novafoundation/nova/core_db/dao/Helpers.kt

@@ -58,6 +58,7 @@ fun chainOf(
     isTestNet = false,
     isEthereumBased = false,
     isTronBased = false,
+    isBitcoinBased = false,
     hasCrowdloans = false,
     additional = "",
     governance = "governance",

core-db/src/main/java/io/novafoundation/nova/core_db/AppDatabase.kt

@@ -94,6 +94,7 @@ import io.novafoundation.nova.core_db.migrations.AddStakingTypeToTotalRewards_44
 import io.novafoundation.nova.core_db.migrations.AddSwapOption_48_49
 import io.novafoundation.nova.core_db.migrations.AddTransactionVersionToRuntime_50_51
 import io.novafoundation.nova.core_db.migrations.AddTransferApisTable_29_30
+import io.novafoundation.nova.core_db.migrations.AddBitcoinSupport_74_75
 import io.novafoundation.nova.core_db.migrations.AddTronSupport_73_74
 import io.novafoundation.nova.core_db.migrations.AddTypeExtrasToMetaAccount_68_69
 import io.novafoundation.nova.core_db.migrations.AddVersioningToGovernanceDapps_32_33
@@ -167,7 +168,7 @@ import io.novafoundation.nova.core_db.model.operation.SwapTypeLocal
 import io.novafoundation.nova.core_db.model.operation.TransferTypeLocal
 
 @Database(
-    version = 74,
+    version = 75,
     entities = [
         AccountLocal::class,
         NodeLocal::class,
@@ -273,6 +274,7 @@ abstract class AppDatabase : RoomDatabase() {
                     .addMigrations(AddTypeExtrasToMetaAccount_68_69, AddMultisigCalls_69_70, AddMultisigSupportFlag_70_71)
                     .addMigrations(AddGifts_71_72, AddFieldsToContributions)
                     .addMigrations(AddTronSupport_73_74)
+                    .addMigrations(AddBitcoinSupport_74_75)
                     .build()
             }
             return instance!!

core-db/src/main/java/io/novafoundation/nova/core_db/dao/ChainDao.kt

@@ -164,7 +164,12 @@ abstract class ChainDao {
 
     // ------- Queries ------
 
-    @Query("SELECT * FROM chains")
+    // ORDER BY rowid: without an explicit order, SQLite gives no guarantee about row order for `SELECT *`.
+    // The merged chains.json lists Pezkuwi's own chains first (see wallet-utils' merge_chains()), and that
+    // order is what gets inserted first on initial sync - rowid tracks insertion order, so ordering by it
+    // means Pezkuwi's chains reliably register/connect first instead of being interleaved unpredictably
+    // among the ~90+ Nova-inherited chains, where they could otherwise end up processed last.
+    @Query("SELECT * FROM chains ORDER BY rowid")
     @Transaction
     abstract suspend fun getJoinChainInfo(): List<JoinedChainInfo>
 
@@ -172,7 +177,7 @@ abstract class ChainDao {
     @Transaction
     abstract suspend fun getAllChainIds(): List<String>
 
-    @Query("SELECT * FROM chains")
+    @Query("SELECT * FROM chains ORDER BY rowid")
     @Transaction
     abstract fun joinChainInfoFlow(): Flow<List<JoinedChainInfo>>
 

core-db/src/main/java/io/novafoundation/nova/core_db/migrations/74_75_AddBitcoinSupport.kt

@@ -0,0 +1,14 @@
+package io.novafoundation.nova.core_db.migrations
+
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+
+val AddBitcoinSupport_74_75 = object : Migration(74, 75) {
+
+    override fun migrate(db: SupportSQLiteDatabase) {
+        db.execSQL("ALTER TABLE chains ADD COLUMN isBitcoinBased INTEGER NOT NULL DEFAULT 0")
+
+        db.execSQL("ALTER TABLE meta_accounts ADD COLUMN bitcoinPublicKey BLOB")
+        db.execSQL("ALTER TABLE meta_accounts ADD COLUMN bitcoinAddress BLOB")
+    }
+}

core-db/src/main/java/io/novafoundation/nova/core_db/model/chain/ChainLocal.kt

@@ -23,6 +23,8 @@ data class ChainLocal(
     val isEthereumBased: Boolean,
     @ColumnInfo(defaultValue = "0")
     val isTronBased: Boolean,
+    @ColumnInfo(defaultValue = "0")
+    val isBitcoinBased: Boolean,
     val isTestNet: Boolean,
     @ColumnInfo(defaultValue = "1")
     val hasSubstrateRuntime: Boolean,

core-db/src/main/java/io/novafoundation/nova/core_db/model/chain/account/MetaAccountLocal.kt

@@ -39,6 +39,8 @@ class MetaAccountLocal(
     val typeExtras: SerializedJson?,
     val tronPublicKey: ByteArray? = null,
     val tronAddress: ByteArray? = null,
+    val bitcoinPublicKey: ByteArray? = null,
+    val bitcoinAddress: ByteArray? = null,
 ) {
 
     enum class Status {
@@ -59,6 +61,9 @@ class MetaAccountLocal(
             const val TRON_PUBKEY = "tronPublicKey"
             const val TRON_ADDRESS = "tronAddress"
 
+            const val BITCOIN_PUBKEY = "bitcoinPublicKey"
+            const val BITCOIN_ADDRESS = "bitcoinAddress"
+
             const val NAME = "name"
             const val IS_SELECTED = "isSelected"
             const val POSITION = "position"
@@ -74,6 +79,62 @@ class MetaAccountLocal(
     fun addEvmAccount(
         ethereumPublicKey: ByteArray,
         ethereumAddress: ByteArray,
+    ): MetaAccountLocal {
+        return MetaAccountLocal(
+            substratePublicKey = substratePublicKey,
+            substrateCryptoType = substrateCryptoType,
+            substrateAccountId = substrateAccountId,
+            ethereumPublicKey = ethereumPublicKey,
+            ethereumAddress = ethereumAddress,
+            name = name,
+            parentMetaId = parentMetaId,
+            isSelected = isSelected,
+            position = position,
+            type = type,
+            status = status,
+            globallyUniqueId = globallyUniqueId,
+            typeExtras = typeExtras,
+            tronPublicKey = tronPublicKey,
+            tronAddress = tronAddress,
+            bitcoinPublicKey = bitcoinPublicKey,
+            bitcoinAddress = bitcoinAddress,
+        ).also {
+            it.id = id
+        }
+    }
+
+    // We do not use copy as we need explicitly set id
+    fun addBitcoinAccount(
+        bitcoinPublicKey: ByteArray,
+        bitcoinAddress: ByteArray,
+    ): MetaAccountLocal {
+        return MetaAccountLocal(
+            substratePublicKey = substratePublicKey,
+            substrateCryptoType = substrateCryptoType,
+            substrateAccountId = substrateAccountId,
+            ethereumPublicKey = ethereumPublicKey,
+            ethereumAddress = ethereumAddress,
+            name = name,
+            parentMetaId = parentMetaId,
+            isSelected = isSelected,
+            position = position,
+            type = type,
+            status = status,
+            globallyUniqueId = globallyUniqueId,
+            typeExtras = typeExtras,
+            tronPublicKey = tronPublicKey,
+            tronAddress = tronAddress,
+            bitcoinPublicKey = bitcoinPublicKey,
+            bitcoinAddress = bitcoinAddress,
+        ).also {
+            it.id = id
+        }
+    }
+
+    // We do not use copy as we need explicitly set id
+    fun addTronAccount(
+        tronPublicKey: ByteArray,
+        tronAddress: ByteArray,
     ): MetaAccountLocal {
         return MetaAccountLocal(
             substratePublicKey = substratePublicKey,
@@ -109,6 +170,8 @@ class MetaAccountLocal(
         if (!ethereumAddress.contentEquals(other.ethereumAddress)) return false
         if (!tronPublicKey.contentEquals(other.tronPublicKey)) return false
         if (!tronAddress.contentEquals(other.tronAddress)) return false
+        if (!bitcoinPublicKey.contentEquals(other.bitcoinPublicKey)) return false
+        if (!bitcoinAddress.contentEquals(other.bitcoinAddress)) return false
         if (name != other.name) return false
         if (parentMetaId != other.parentMetaId) return false
         if (isSelected != other.isSelected) return false
@@ -130,6 +193,8 @@ class MetaAccountLocal(
         result = 31 * result + (ethereumAddress?.contentHashCode() ?: 0)
         result = 31 * result + (tronPublicKey?.contentHashCode() ?: 0)
         result = 31 * result + (tronAddress?.contentHashCode() ?: 0)
+        result = 31 * result + (bitcoinPublicKey?.contentHashCode() ?: 0)
+        result = 31 * result + (bitcoinAddress?.contentHashCode() ?: 0)
         result = 31 * result + name.hashCode()
         result = 31 * result + (parentMetaId?.hashCode() ?: 0)
         result = 31 * result + isSelected.hashCode()

feature-account-api/src/main/java/io/novafoundation/nova/feature_account_api/data/model/Fee.kt

@@ -63,6 +63,31 @@ class SubstrateFee(
     override val asset: Chain.Asset
 ) : Fee
 
+/**
+ * Fee for a Bitcoin transaction, denominated in sats: `feeRate (sat/vB) * estimated vsize` - see
+ * `RealBitcoinTransactionService` for how both are derived. The network only ever collects what miners include
+ * in a block, which is exactly this amount (unlike account-model chains, a Bitcoin fee is not a cap/estimate
+ * that gets partially refunded - it is the literal difference between input and output values).
+ */
+class BitcoinFee(
+    override val amount: BigInteger,
+    override val submissionOrigin: SubmissionOrigin,
+    override val asset: Chain.Asset
+) : Fee
+
+/**
+ * Fee for a Tron transaction (native TRX or TRC-20), always denominated in TRX (sun), regardless of which asset
+ * is being sent - Tron has no separate "gas token" concept, network resources (bandwidth/energy) are always
+ * burned as TRX. [amount] is this client's own estimate of that burn (see `RealTronTransactionService`); the
+ * network only ever burns what it actually uses, so the real cost can be lower, but never higher than what this
+ * client authorized via `fee_limit` when submitting.
+ */
+class TronFee(
+    override val amount: BigInteger,
+    override val submissionOrigin: SubmissionOrigin,
+    override val asset: Chain.Asset
+) : Fee
+
 class SubstrateFeeBase(
     override val amount: BigInteger,
     override val asset: Chain.Asset

feature-account-api/src/main/java/io/novafoundation/nova/feature_account_api/data/secrets/SecretStoreExt.kt

@@ -25,14 +25,14 @@ suspend fun SecretStoreV2.getAccountSecrets(
 
 fun AccountSecrets.keypair(chain: Chain): Keypair {
     return fold(
-        left = { mapMetaAccountSecretsToKeypair(it, ethereum = chain.isEthereumBased) },
+        left = { mapMetaAccountSecretsToKeypair(it, ethereum = chain.isEthereumBased, bitcoin = chain.isBitcoinBased) },
         right = { mapChainAccountSecretsToKeypair(it) }
     )
 }
 
 fun AccountSecrets.derivationPath(chain: Chain): String? {
     return fold(
-        left = { mapMetaAccountSecretsToDerivationPath(it, ethereum = chain.isEthereumBased) },
+        left = { mapMetaAccountSecretsToDerivationPath(it, ethereum = chain.isEthereumBased, bitcoin = chain.isBitcoinBased) },
         right = { it[ChainAccountSecrets.DerivationPath] }
     )
 }

feature-account-api/src/main/java/io/novafoundation/nova/feature_account_api/domain/model/MetaAccount.kt

@@ -52,6 +52,10 @@ interface LightMetaAccount {
      */
     val tronAddress: ByteArray?
     val tronPublicKey: ByteArray?
+
+    /** Bitcoin account id (HASH160 of the compressed pubkey - see [io.novafoundation.nova.common.utils.hash160]). */
+    val bitcoinAddress: ByteArray?
+    val bitcoinPublicKey: ByteArray?
     val isSelected: Boolean
     val name: String
     val type: Type
@@ -90,6 +94,8 @@ fun LightMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) = object : LightMetaAccount {
     override val id: Long = id
     override val globallyUniqueId: String = globallyUniqueId
@@ -100,6 +106,8 @@ fun LightMetaAccount(
     override val ethereumPublicKey: ByteArray? = ethereumPublicKey
     override val tronAddress: ByteArray? = tronAddress
     override val tronPublicKey: ByteArray? = tronPublicKey
+    override val bitcoinAddress: ByteArray? = bitcoinAddress
+    override val bitcoinPublicKey: ByteArray? = bitcoinPublicKey
     override val isSelected: Boolean = isSelected
     override val name: String = name
     override val type: LightMetaAccount.Type = type

feature-account-impl/build.gradle

@@ -13,6 +13,16 @@ android {
     buildFeatures {
         viewBinding true
     }
+
+    testOptions {
+        unitTests {
+            // android.util.Log.* throws "Method ... not mocked" by default in plain JVM unit tests (no real
+            // Android framework, no Robolectric) - TronAddressBackfillMigrationTest is the first test in this
+            // module to exercise code that calls Log.d/Log.e. This makes those stubbed calls return harmless
+            // defaults instead of throwing, which is what the framework's own stubs are meant for in this context.
+            returnDefaultValues = true
+        }
+    }
 }
 
 dependencies {

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/cloudBackup/RealLocalAccountsCloudBackupFacade.kt

@@ -7,6 +7,8 @@ import io.novafoundation.nova.common.data.secrets.v2.KeyPairSchema
 import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
 import io.novafoundation.nova.common.data.secrets.v2.SecretStoreV2
 import io.novafoundation.nova.common.data.secrets.v2.derivationPath
+import io.novafoundation.nova.common.data.secrets.v2.bitcoinDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.bitcoinKeypair
 import io.novafoundation.nova.common.data.secrets.v2.entropy
 import io.novafoundation.nova.common.data.secrets.v2.ethereumDerivationPath
 import io.novafoundation.nova.common.data.secrets.v2.ethereumKeypair
@@ -17,6 +19,8 @@ import io.novafoundation.nova.common.data.secrets.v2.publicKey
 import io.novafoundation.nova.common.data.secrets.v2.seed
 import io.novafoundation.nova.common.data.secrets.v2.substrateDerivationPath
 import io.novafoundation.nova.common.data.secrets.v2.substrateKeypair
+import io.novafoundation.nova.common.data.secrets.v2.tronDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.tronKeypair
 import io.novafoundation.nova.common.utils.filterNotNull
 import io.novafoundation.nova.common.utils.findById
 import io.novafoundation.nova.common.utils.mapToSet
@@ -90,6 +94,8 @@ class RealLocalAccountsCloudBackupFacade(
             substrate = baseSecrets.getSubstrateBackupSecrets(),
             ethereum = baseSecrets.getEthereumBackupSecrets(),
             chainAccounts = emptyList(),
+            bitcoin = baseSecrets.getBitcoinBackupSecrets(),
+            tron = baseSecrets.getTronBackupSecrets(),
         )
 
         return CloudBackup(
@@ -357,6 +363,8 @@ class RealLocalAccountsCloudBackupFacade(
             substrate = prepareSubstrateBackupSecrets(baseSecrets, joinedMetaAccountInfo),
             ethereum = baseSecrets.getEthereumBackupSecrets(),
             chainAccounts = chainAccountsFromChainSecrets + chainAccountFromAdditionalSecrets,
+            bitcoin = baseSecrets.getBitcoinBackupSecrets(),
+            tron = baseSecrets.getTronBackupSecrets(),
         )
     }
 
@@ -466,7 +474,11 @@ class RealLocalAccountsCloudBackupFacade(
             substrateKeyPair = substrate?.keypair?.toLocalKeyPair() ?: return null,
             substrateDerivationPath = substrate?.derivationPath,
             ethereumKeypair = ethereum?.keypair?.toLocalKeyPair(),
-            ethereumDerivationPath = ethereum?.derivationPath
+            ethereumDerivationPath = ethereum?.derivationPath,
+            bitcoinKeypair = bitcoin?.keypair?.toLocalKeyPair(),
+            bitcoinDerivationPath = bitcoin?.derivationPath,
+            tronKeypair = tron?.keypair?.toLocalKeyPair(),
+            tronDerivationPath = tron?.derivationPath
         )
     }
 
@@ -479,6 +491,24 @@ class RealLocalAccountsCloudBackupFacade(
         )
     }
 
+    private fun EncodableStruct<MetaAccountSecrets>?.getBitcoinBackupSecrets(): CloudBackup.WalletPrivateInfo.BitcoinSecrets? {
+        if (this == null) return null
+
+        return CloudBackup.WalletPrivateInfo.BitcoinSecrets(
+            keypair = bitcoinKeypair?.toBackupKeypairSecrets() ?: return null,
+            derivationPath = bitcoinDerivationPath
+        )
+    }
+
+    private fun EncodableStruct<MetaAccountSecrets>?.getTronBackupSecrets(): CloudBackup.WalletPrivateInfo.TronSecrets? {
+        if (this == null) return null
+
+        return CloudBackup.WalletPrivateInfo.TronSecrets(
+            keypair = tronKeypair?.toBackupKeypairSecrets() ?: return null,
+            derivationPath = tronDerivationPath
+        )
+    }
+
     private fun EncodableStruct<MetaAccountSecrets>?.getSubstrateBackupSecrets(): CloudBackup.WalletPrivateInfo.SubstrateSecrets? {
         if (this == null) return null
 
@@ -520,7 +550,11 @@ class RealLocalAccountsCloudBackupFacade(
             ethereumPublicKey = metaAccount.ethereumPublicKey,
             name = metaAccount.name,
             type = metaAccount.type.toBackupWalletType() ?: return null,
-            chainAccounts = chainAccounts.mapToSet { chainAccount -> chainAccount.toBackupPublicChainAccount(chainsById) }
+            chainAccounts = chainAccounts.mapToSet { chainAccount -> chainAccount.toBackupPublicChainAccount(chainsById) },
+            bitcoinAddress = metaAccount.bitcoinAddress,
+            bitcoinPublicKey = metaAccount.bitcoinPublicKey,
+            tronAddress = metaAccount.tronAddress,
+            tronPublicKey = metaAccount.tronPublicKey,
         )
     }
 
@@ -542,7 +576,11 @@ class RealLocalAccountsCloudBackupFacade(
             isSelected = isSelected,
             position = accountPosition,
             status = MetaAccountLocal.Status.ACTIVE,
-            typeExtras = null
+            typeExtras = null,
+            bitcoinAddress = bitcoinAddress,
+            bitcoinPublicKey = bitcoinPublicKey,
+            tronAddress = tronAddress,
+            tronPublicKey = tronPublicKey,
         ).also {
             if (localIdOverwrite != null) {
                 it.id = localIdOverwrite

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/mappers/AccountMappers.kt

@@ -65,6 +65,8 @@ class AccountMappers(
                     ethereumPublicKey = ethereumPublicKey,
                     tronAddress = tronAddress,
                     tronPublicKey = tronPublicKey,
+                    bitcoinAddress = bitcoinAddress,
+                    bitcoinPublicKey = bitcoinPublicKey,
                     isSelected = isSelected,
                     name = name,
                     status = mapMetaAccountStateFromLocal(status),
@@ -82,6 +84,8 @@ class AccountMappers(
                     ethereumPublicKey = ethereumPublicKey,
                     tronAddress = tronAddress,
                     tronPublicKey = tronPublicKey,
+                    bitcoinAddress = bitcoinAddress,
+                    bitcoinPublicKey = bitcoinPublicKey,
                     isSelected = isSelected,
                     name = name,
                     type = type,
@@ -101,6 +105,8 @@ class AccountMappers(
                     ethereumPublicKey = ethereumPublicKey,
                     tronAddress = tronAddress,
                     tronPublicKey = tronPublicKey,
+                    bitcoinAddress = bitcoinAddress,
+                    bitcoinPublicKey = bitcoinPublicKey,
                     isSelected = isSelected,
                     name = name,
                     type = type,
@@ -119,6 +125,8 @@ class AccountMappers(
                     ethereumPublicKey = ethereumPublicKey,
                     tronAddress = tronAddress,
                     tronPublicKey = tronPublicKey,
+                    bitcoinAddress = bitcoinAddress,
+                    bitcoinPublicKey = bitcoinPublicKey,
                     isSelected = isSelected,
                     name = name,
                     type = type,
@@ -138,6 +146,8 @@ class AccountMappers(
                     ethereumPublicKey = ethereumPublicKey,
                     tronAddress = tronAddress,
                     tronPublicKey = tronPublicKey,
+                    bitcoinAddress = bitcoinAddress,
+                    bitcoinPublicKey = bitcoinPublicKey,
                     isSelected = isSelected,
                     name = name,
                     type = type,
@@ -165,6 +175,8 @@ class AccountMappers(
                         ethereumPublicKey = ethereumPublicKey,
                         tronAddress = tronAddress,
                         tronPublicKey = tronPublicKey,
+                        bitcoinAddress = bitcoinAddress,
+                        bitcoinPublicKey = bitcoinPublicKey,
                         isSelected = isSelected,
                         name = name,
                         status = mapMetaAccountStateFromLocal(status),
@@ -183,6 +195,8 @@ class AccountMappers(
                         ethereumPublicKey = ethereumPublicKey,
                         tronAddress = tronAddress,
                         tronPublicKey = tronPublicKey,
+                        bitcoinAddress = bitcoinAddress,
+                        bitcoinPublicKey = bitcoinPublicKey,
                         chainAccounts = chainAccounts,
                         isSelected = isSelected,
                         name = name,

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/repository/datasource/AccountDataSourceImpl.kt

@@ -30,6 +30,8 @@ import io.novafoundation.nova.feature_account_impl.data.mappers.AccountMappers
 import io.novafoundation.nova.feature_account_impl.data.mappers.mapMetaAccountTypeToLocal
 import io.novafoundation.nova.feature_account_impl.data.mappers.mapMetaAccountWithBalanceFromLocal
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.AccountDataMigration
+import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.BitcoinAddressBackfillMigration
+import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.TronAddressBackfillMigration
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.model.ChainAccountInsertionData
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.model.MetaAccountInsertionData
 import io.novafoundation.nova.runtime.ext.accountIdOf
@@ -64,15 +66,40 @@ class AccountDataSourceImpl(
     private val secretsMetaAccountLocalFactory: SecretsMetaAccountLocalFactory,
     secretStoreV1: SecretStoreV1,
     accountDataMigration: AccountDataMigration,
+    tronAddressBackfillMigration: TronAddressBackfillMigration,
+    bitcoinAddressBackfillMigration: BitcoinAddressBackfillMigration,
 ) : AccountDataSource, SecretStoreV1 by secretStoreV1 {
 
     init {
-        migrateIfNeeded(accountDataMigration)
+        // Run sequentially in one coroutine, not as independent launches - the Tron/Bitcoin backfills read
-    }
+        // accounts/secrets that the legacy migration may still be in the middle of writing for very old
+        // (pre-MetaAccount) installs, and separate GlobalScope.launch calls give no ordering guarantee
+        // relative to each other.
+        async {
+            Log.d("AccountDataSourceImpl", "migrations block starting")
 
-    private fun migrateIfNeeded(migration: AccountDataMigration) = async {
+            if (accountDataMigration.migrationNeeded()) {
-        if (migration.migrationNeeded()) {
+                accountDataMigration.migrate(::saveSecuritySource)
-            migration.migrate(::saveSecuritySource)
+            }
+
+            Log.d("AccountDataSourceImpl", "about to run tronAddressBackfillMigration")
+
+            tronAddressBackfillMigration.migrate()
+
+            Log.d("AccountDataSourceImpl", "about to run bitcoinAddressBackfillMigration")
+
+            bitcoinAddressBackfillMigration.migrate()
+
+            Log.d("AccountDataSourceImpl", "migrations block done")
+
+            metaAccountDao.getMetaAccounts().forEach {
+                Log.d(
+                    "TronDiag",
+                    "metaId=${it.id} name=${it.name} type=${it.type} isSelected=${it.isSelected} " +
+                        "tronAddress=${it.tronAddress?.joinToString("") { b -> "%02x".format(b) } ?: "NULL"} " +
+                        "tronPublicKey=${if (it.tronPublicKey != null) "present(${it.tronPublicKey!!.size}B)" else "NULL"}"
+                )
+            }
         }
     }
 

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/repository/datasource/SecretsMetaAccountLocalFactory.kt

@@ -2,6 +2,7 @@ package io.novafoundation.nova.feature_account_impl.data.repository.datasource
 
 import io.novafoundation.nova.common.data.secrets.v2.KeyPairSchema
 import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
+import io.novafoundation.nova.common.utils.bitcoinPublicKeyToAccountId
 import io.novafoundation.nova.common.utils.substrateAccountId
 import io.novafoundation.nova.common.utils.tronPublicKeyToAccountId
 import io.novafoundation.nova.core.model.CryptoType
@@ -31,6 +32,7 @@ class RealSecretsMetaAccountLocalFactory : SecretsMetaAccountLocalFactory {
         val substratePublicKey = secrets[MetaAccountSecrets.SubstrateKeypair][KeyPairSchema.PublicKey]
         val ethereumPublicKey = secrets[MetaAccountSecrets.EthereumKeypair]?.get(KeyPairSchema.PublicKey)
         val tronPublicKey = secrets[MetaAccountSecrets.TronKeypair]?.get(KeyPairSchema.PublicKey)
+        val bitcoinPublicKey = secrets[MetaAccountSecrets.BitcoinKeypair]?.get(KeyPairSchema.PublicKey)
 
         return MetaAccountLocal(
             substratePublicKey = substratePublicKey,
@@ -47,7 +49,13 @@ class RealSecretsMetaAccountLocalFactory : SecretsMetaAccountLocalFactory {
             globallyUniqueId = MetaAccountLocal.generateGloballyUniqueId(),
             typeExtras = null,
             tronPublicKey = tronPublicKey,
-            tronAddress = tronPublicKey?.tronPublicKeyToAccountId()
+            tronAddress = tronPublicKey?.tronPublicKeyToAccountId(),
+            bitcoinPublicKey = bitcoinPublicKey,
+            // Bip32EcdsaKeypairFactory already yields a compressed (33-byte) public key (confirmed against
+            // substrate-sdk-android's own source: ECDSAUtils.derivePublicKey -> compressedPublicKeyFromPrivate),
+            // which is exactly the format both BIP143 (P2WPKH) and bitcoinPublicKeyToAccountId() require - no
+            // extra compression/decompression step needed here, unlike Ethereum's uncompressed-key derivation.
+            bitcoinAddress = bitcoinPublicKey?.bitcoinPublicKeyToAccountId()
         )
     }
 }

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/repository/datasource/migration/BitcoinAddressBackfillMigration.kt

@@ -0,0 +1,119 @@
+package io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration
+
+import android.util.Log
+import io.novafoundation.nova.common.data.secrets.v2.ChainAccountSecrets
+import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
+import io.novafoundation.nova.common.data.secrets.v2.SecretStoreV2
+import io.novafoundation.nova.common.data.secrets.v2.bitcoinDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.bitcoinKeypair
+import io.novafoundation.nova.common.data.secrets.v2.entropy
+import io.novafoundation.nova.common.data.secrets.v2.ethereumDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.ethereumKeypair
+import io.novafoundation.nova.common.data.secrets.v2.mapKeypairStructToKeypair
+import io.novafoundation.nova.common.data.secrets.v2.seed
+import io.novafoundation.nova.common.data.secrets.v2.substrateDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.substrateKeypair
+import io.novafoundation.nova.common.data.secrets.v2.tronDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.tronKeypair
+import io.novafoundation.nova.common.utils.bitcoinPublicKeyToAccountId
+import io.novafoundation.nova.core_db.dao.MetaAccountDao
+import io.novafoundation.nova.core_db.dao.updateMetaAccount
+import io.novafoundation.nova.core_db.model.chain.account.MetaAccountLocal
+import io.novafoundation.nova.feature_account_impl.data.secrets.AccountSecretsFactory
+import io.novafoundation.nova.feature_account_impl.data.secrets.BITCOIN_DEFAULT_DERIVATION_PATH
+import io.novasama.substrate_sdk_android.encrypt.mnemonic.MnemonicCreator
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+private const val TAG = "BitcoinAddressBackfill"
+
+/**
+ * Idempotent, per-account backfill for accounts that don't yet have a Bitcoin keypair - mirrors
+ * [TronAddressBackfillMigration]'s exact design (see that class for the full rationale): any account created
+ * before Bitcoin support existed has no `MetaAccountSecrets.BitcoinKeypair`/`meta_accounts.bitcoinAddress` yet,
+ * and this fills it in from the account's own mnemonic without requiring re-import.
+ *
+ * Deliberately has NO "have I already run once" flag, for the same reason as the Tron migration: a one-shot
+ * flag that gets set even when backfill legitimately still didn't produce a key (e.g. a since-fixed bug kept
+ * re-losing it) would permanently strand that account. This is cheap to call for an account that doesn't need
+ * it, so it just runs unconditionally on every app start.
+ *
+ * Only touches accounts that are `Type.SECRETS` (mnemonic-derived) and still hold their `Entropy` in
+ * [SecretStoreV2] - same restriction as the Tron migration, for the same reason (watch-only/Ledger/Json/
+ * multisig/proxied accounts and raw-seed imports never had a Bitcoin-capable mnemonic to derive from).
+ */
+class BitcoinAddressBackfillMigration(
+    private val secretStoreV2: SecretStoreV2,
+    private val metaAccountDao: MetaAccountDao,
+    private val accountSecretsFactory: AccountSecretsFactory,
+) {
+
+    suspend fun migrate() = withContext(Dispatchers.Default) {
+        val secretsAccounts = metaAccountDao.getMetaAccounts().filter { it.type == MetaAccountLocal.Type.SECRETS }
+        Log.d(TAG, "migrate() starting - ${secretsAccounts.size} SECRETS-type account(s): ${secretsAccounts.map { it.id }}")
+
+        secretsAccounts.forEach { account ->
+            try {
+                backfillIfNeeded(account)
+            } catch (e: Throwable) {
+                Log.e(TAG, "backfill failed for metaId=${account.id}, continuing with remaining accounts", e)
+            }
+        }
+
+        Log.d(TAG, "migrate() done")
+    }
+
+    private suspend fun backfillIfNeeded(account: MetaAccountLocal) {
+        val secrets = secretStoreV2.getMetaAccountSecrets(account.id)
+        if (secrets == null) {
+            Log.d(TAG, "metaId=${account.id}: no stored secrets at all (watch-only/Ledger/etc) - skipping")
+            return
+        }
+        val entropy = secrets.entropy
+        if (entropy == null) {
+            Log.d(TAG, "metaId=${account.id}: no entropy (raw-seed import, not a mnemonic) - skipping")
+            return
+        }
+        if (secrets.bitcoinKeypair != null) {
+            Log.d(TAG, "metaId=${account.id}: already has a BitcoinKeypair - skipping")
+            return
+        }
+        val substrateCryptoType = account.substrateCryptoType
+        if (substrateCryptoType == null) {
+            Log.d(TAG, "metaId=${account.id}: substrateCryptoType is null - skipping")
+            return
+        }
+
+        Log.d(TAG, "metaId=${account.id}: deriving Bitcoin keypair")
+
+        val mnemonic = MnemonicCreator.fromEntropy(entropy).words
+
+        val bitcoinChainSecrets = accountSecretsFactory.chainAccountSecrets(
+            derivationPath = BITCOIN_DEFAULT_DERIVATION_PATH,
+            accountSource = AccountSecretsFactory.AccountSource.Mnemonic(substrateCryptoType, mnemonic),
+            isEthereum = true
+        ).secrets
+
+        val bitcoinKeypair = mapKeypairStructToKeypair(bitcoinChainSecrets[ChainAccountSecrets.Keypair])
+
+        val updatedSecrets = MetaAccountSecrets(
+            substrateKeyPair = mapKeypairStructToKeypair(secrets.substrateKeypair),
+            entropy = secrets.entropy,
+            substrateSeed = secrets.seed,
+            substrateDerivationPath = secrets.substrateDerivationPath,
+            ethereumKeypair = secrets.ethereumKeypair?.let(::mapKeypairStructToKeypair),
+            ethereumDerivationPath = secrets.ethereumDerivationPath,
+            tronKeypair = secrets.tronKeypair?.let(::mapKeypairStructToKeypair),
+            tronDerivationPath = secrets.tronDerivationPath,
+            bitcoinKeypair = bitcoinKeypair,
+            bitcoinDerivationPath = BITCOIN_DEFAULT_DERIVATION_PATH
+        )
+
+        secretStoreV2.putMetaAccountSecrets(account.id, updatedSecrets)
+
+        val bitcoinAccountId = bitcoinKeypair.publicKey.bitcoinPublicKeyToAccountId()
+        metaAccountDao.updateMetaAccount(account.id) { it.addBitcoinAccount(bitcoinKeypair.publicKey, bitcoinAccountId) }
+
+        Log.d(TAG, "metaId=${account.id}: backfilled successfully, bitcoinAddress set (${bitcoinAccountId.size} bytes)")
+    }
+}

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/repository/datasource/migration/TronAddressBackfillMigration.kt

@@ -0,0 +1,128 @@
+package io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration
+
+import android.util.Log
+import io.novafoundation.nova.common.data.secrets.v2.ChainAccountSecrets
+import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
+import io.novafoundation.nova.common.data.secrets.v2.SecretStoreV2
+import io.novafoundation.nova.common.data.secrets.v2.entropy
+import io.novafoundation.nova.common.data.secrets.v2.ethereumDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.ethereumKeypair
+import io.novafoundation.nova.common.data.secrets.v2.mapKeypairStructToKeypair
+import io.novafoundation.nova.common.data.secrets.v2.seed
+import io.novafoundation.nova.common.data.secrets.v2.substrateDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.substrateKeypair
+import io.novafoundation.nova.common.data.secrets.v2.tronKeypair
+import io.novafoundation.nova.common.utils.tronPublicKeyToAccountId
+import io.novafoundation.nova.core_db.dao.MetaAccountDao
+import io.novafoundation.nova.core_db.dao.updateMetaAccount
+import io.novafoundation.nova.core_db.model.chain.account.MetaAccountLocal
+import io.novafoundation.nova.feature_account_impl.data.secrets.AccountSecretsFactory
+import io.novafoundation.nova.feature_account_impl.data.secrets.TRON_DEFAULT_DERIVATION_PATH
+import io.novasama.substrate_sdk_android.encrypt.mnemonic.MnemonicCreator
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+private const val TAG = "TronAddressBackfill"
+
+/**
+ * Idempotent, per-account backfill for accounts that don't yet have a Tron keypair - both accounts created
+ * before Tron support existed, AND accounts whose Tron keypair was lost some other way (e.g. the cloud-backup
+ * schema round trip that used to silently drop it before every wallet had a `tron` field to serialize into -
+ * see CloudBackup.kt). `73_74_AddTronSupport` (the migration that added `meta_accounts.tronPublicKey`/
+ * `tronAddress`) is, like every other migration in this codebase, pure `ALTER TABLE` - it never derives a value
+ * for pre-existing rows.
+ *
+ * Deliberately has NO "have I already run once" flag: an earlier version of this class gated itself behind a
+ * one-shot SharedPreferences flag, which meant that once it ran and marked itself done - even for an account
+ * that legitimately still lacked a Tron keypair afterwards (e.g. because a *different*, since-fixed bug kept
+ * re-losing it) - it would never run again for that account, ever, on that install. [backfillIfNeeded] is cheap
+ * to call for an account that doesn't need it (a handful of null-checks, no derivation), so this just runs
+ * unconditionally on every app start instead: self-healing by construction, no stuck-flag failure mode possible.
+ *
+ * Only touches accounts that are:
+ * - `Type.SECRETS` (mnemonic-derived) - watch-only/Ledger/Json/multisig/proxied accounts never had a
+ *   Tron-capable mnemonic and are correctly left with `tronAddress == null` forever, same as they already are
+ *   for Ethereum.
+ * - still holding their `Entropy` in [SecretStoreV2] - an account imported from a raw seed/keypair rather than
+ *   a mnemonic has no entropy either and is likewise correctly left alone.
+ * - missing a `TronKeypair` - i.e. not already backfilled and not created after Tron support shipped.
+ *
+ * The Tron keypair is derived via [AccountSecretsFactory.chainAccountSecrets] with `isEthereum = true` (Tron
+ * reuses the exact same secp256k1/BIP32 derivation as Ethereum, just under its own SLIP-44 coin-type-195 path -
+ * see that class's own doc comment) at [TRON_DEFAULT_DERIVATION_PATH], the same call this codebase's own
+ * `metaAccountSecrets()` makes for a fresh account - so a backfilled account ends up with byte-for-byte the
+ * same Tron address it would have gotten had it been created today, not a separately-reimplemented derivation.
+ */
+class TronAddressBackfillMigration(
+    private val secretStoreV2: SecretStoreV2,
+    private val metaAccountDao: MetaAccountDao,
+    private val accountSecretsFactory: AccountSecretsFactory,
+) {
+
+    suspend fun migrate() = withContext(Dispatchers.Default) {
+        val secretsAccounts = metaAccountDao.getMetaAccounts().filter { it.type == MetaAccountLocal.Type.SECRETS }
+        Log.d(TAG, "migrate() starting - ${secretsAccounts.size} SECRETS-type account(s): ${secretsAccounts.map { it.id }}")
+
+        secretsAccounts.forEach { account ->
+            try {
+                backfillIfNeeded(account)
+            } catch (e: Throwable) {
+                Log.e(TAG, "backfill failed for metaId=${account.id}, continuing with remaining accounts", e)
+            }
+        }
+
+        Log.d(TAG, "migrate() done")
+    }
+
+    private suspend fun backfillIfNeeded(account: MetaAccountLocal) {
+        val secrets = secretStoreV2.getMetaAccountSecrets(account.id)
+        if (secrets == null) {
+            Log.d(TAG, "metaId=${account.id}: no stored secrets at all (watch-only/Ledger/etc) - skipping")
+            return
+        }
+        val entropy = secrets.entropy
+        if (entropy == null) {
+            Log.d(TAG, "metaId=${account.id}: no entropy (raw-seed import, not a mnemonic) - skipping")
+            return
+        }
+        if (secrets.tronKeypair != null) {
+            Log.d(TAG, "metaId=${account.id}: already has a TronKeypair - skipping")
+            return
+        }
+        val substrateCryptoType = account.substrateCryptoType
+        if (substrateCryptoType == null) {
+            Log.d(TAG, "metaId=${account.id}: substrateCryptoType is null - skipping")
+            return
+        }
+
+        Log.d(TAG, "metaId=${account.id}: deriving Tron keypair")
+
+        val mnemonic = MnemonicCreator.fromEntropy(entropy).words
+
+        val tronChainSecrets = accountSecretsFactory.chainAccountSecrets(
+            derivationPath = TRON_DEFAULT_DERIVATION_PATH,
+            accountSource = AccountSecretsFactory.AccountSource.Mnemonic(substrateCryptoType, mnemonic),
+            isEthereum = true
+        ).secrets
+
+        val tronKeypair = mapKeypairStructToKeypair(tronChainSecrets[ChainAccountSecrets.Keypair])
+
+        val updatedSecrets = MetaAccountSecrets(
+            substrateKeyPair = mapKeypairStructToKeypair(secrets.substrateKeypair),
+            entropy = secrets.entropy,
+            substrateSeed = secrets.seed,
+            substrateDerivationPath = secrets.substrateDerivationPath,
+            ethereumKeypair = secrets.ethereumKeypair?.let(::mapKeypairStructToKeypair),
+            ethereumDerivationPath = secrets.ethereumDerivationPath,
+            tronKeypair = tronKeypair,
+            tronDerivationPath = TRON_DEFAULT_DERIVATION_PATH
+        )
+
+        secretStoreV2.putMetaAccountSecrets(account.id, updatedSecrets)
+
+        val tronAccountId = tronKeypair.publicKey.tronPublicKeyToAccountId()
+        metaAccountDao.updateMetaAccount(account.id) { it.addTronAccount(tronKeypair.publicKey, tronAccountId) }
+
+        Log.d(TAG, "metaId=${account.id}: backfilled successfully, tronAddress set (${tronAccountId.size} bytes)")
+    }
+}

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/secrets/AccountSecretsFactory.kt

@@ -34,6 +34,14 @@ import kotlinx.coroutines.withContext
  */
 const val TRON_DEFAULT_DERIVATION_PATH = "//44//195//0/0/0"
 
+/**
+ * BIP84 purpose (native SegWit), SLIP-44 coin type 0 (Bitcoin). Deliberately `//84//...`, not `//44//...` -
+ * this app only supports native SegWit (bech32 `bc1q...`) addresses, not legacy/P2SH-SegWit, so the derivation
+ * path signals that choice the same way real Bitcoin wallets do. Not user-configurable yet - always derived at
+ * this fixed path (single address, no HD address-index rotation).
+ */
+const val BITCOIN_DEFAULT_DERIVATION_PATH = "//84//0//0/0/0"
+
 class AccountSecretsFactory(
     private val JsonDecoder: JsonDecoder
 ) {
@@ -131,6 +139,7 @@ class AccountSecretsFactory(
         ethereumDerivationPath: String?,
         accountSource: AccountSource,
         tronDerivationPath: String? = TRON_DEFAULT_DERIVATION_PATH,
+        bitcoinDerivationPath: String? = BITCOIN_DEFAULT_DERIVATION_PATH,
     ): Result<MetaAccountSecrets> = withContext(Dispatchers.Default) {
         val (substrateSecrets, substrateCryptoType) = chainAccountSecrets(
             derivationPath = substrateDerivationPath,
@@ -157,6 +166,16 @@ class AccountSecretsFactory(
             Bip32EcdsaKeypairFactory.generate(seed = seed, junctions = decodedTronDerivationPath?.junctions.orEmpty())
         }
 
+        // Bitcoin (native SegWit) also reuses the exact same secp256k1/BIP32 keypair generation as Ethereum/Tron -
+        // only the SLIP-44 coin type (0) and BIP84 purpose differ. See BITCOIN_DEFAULT_DERIVATION_PATH's doc.
+        val bitcoinKeypair = accountSource.castOrNull<AccountSource.Mnemonic>()?.let {
+            val decodedBitcoinDerivationPath = decodeDerivationPath(bitcoinDerivationPath, ethereum = true)
+
+            val seed = deriveSeed(it.mnemonic, password = decodedBitcoinDerivationPath?.password, ethereum = true).seed
+
+            Bip32EcdsaKeypairFactory.generate(seed = seed, junctions = decodedBitcoinDerivationPath?.junctions.orEmpty())
+        }
+
         val secrets = MetaAccountSecrets(
             entropy = substrateSecrets[ChainAccountSecrets.Entropy],
             substrateSeed = substrateSecrets[ChainAccountSecrets.Seed],
@@ -165,7 +184,9 @@ class AccountSecretsFactory(
             ethereumKeypair = ethereumKeypair,
             ethereumDerivationPath = ethereumDerivationPath,
             tronKeypair = tronKeypair,
-            tronDerivationPath = tronDerivationPath
+            tronDerivationPath = tronDerivationPath,
+            bitcoinKeypair = bitcoinKeypair,
+            bitcoinDerivationPath = bitcoinDerivationPath,
         )
 
         Result(secrets = secrets, cryptoType = substrateCryptoType)

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/data/signer/secrets/SecretsSigner.kt

@@ -142,11 +142,15 @@ class SecretsSigner(
     private suspend fun getKeypair(accountId: AccountId): Keypair {
         val chainsById = chainRegistry.chainsById()
         val multiChainEncryption = metaAccount.multiChainEncryptionFor(accountId, chainsById)!!
+        val isTronBased = metaAccount.tronAddress?.contentEquals(accountId) == true
+        val isBitcoinBased = metaAccount.bitcoinAddress?.contentEquals(accountId) == true
 
         return secretStoreV2.getKeypair(
             metaAccount = metaAccount,
             accountId = accountId,
-            isEthereumBased = multiChainEncryption is MultiChainEncryption.Ethereum
+            isEthereumBased = multiChainEncryption is MultiChainEncryption.Ethereum,
+            isTronBased = isTronBased,
+            isBitcoinBased = isBitcoinBased
         )
     }
 
@@ -159,11 +163,13 @@ class SecretsSigner(
     private suspend fun SecretStoreV2.getKeypair(
         metaAccount: MetaAccount,
         accountId: AccountId,
-        isEthereumBased: Boolean
+        isEthereumBased: Boolean,
+        isTronBased: Boolean = false,
+        isBitcoinBased: Boolean = false,
     ) = if (hasChainSecrets(metaAccount.id, accountId)) {
         getChainAccountKeypair(metaAccount.id, accountId)
     } else {
-        getMetaAccountKeypair(metaAccount.id, isEthereumBased)
+        getMetaAccountKeypair(metaAccount.id, isEthereumBased, isTronBased, isBitcoinBased)
     }
 
     /**
@@ -173,6 +179,12 @@ class SecretsSigner(
         return when {
             substrateAccountId.contentEquals(accountId) -> substrateCryptoType?.let(MultiChainEncryption.Companion::substrateFrom)
             ethereumAccountId().contentEquals(accountId) -> MultiChainEncryption.Ethereum
+            // Tron and Bitcoin both reuse the exact same secp256k1 signing scheme as Ethereum - they just have
+            // their own accountId (different SLIP-44 derivation path), so neither matches ethereumAccountId()
+            // above and was falling through to the chainAccounts lookup, which doesn't cover them either ->
+            // null -> NPE on `!!`.
+            tronAddress?.contentEquals(accountId) == true -> MultiChainEncryption.Ethereum
+            bitcoinAddress?.contentEquals(accountId) == true -> MultiChainEncryption.Ethereum
             else -> {
                 val chainAccount = chainAccounts.values.firstOrNull { it.accountId.contentEquals(accountId) } ?: return null
                 val cryptoType = chainAccount.cryptoType ?: return null

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/di/AccountFeatureModule.kt

@@ -104,6 +104,8 @@ import io.novafoundation.nova.feature_account_impl.data.repository.datasource.Ac
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.RealSecretsMetaAccountLocalFactory
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.SecretsMetaAccountLocalFactory
 import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.AccountDataMigration
+import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.BitcoinAddressBackfillMigration
+import io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration.TronAddressBackfillMigration
 import io.novafoundation.nova.feature_account_impl.data.secrets.AccountSecretsFactory
 import io.novafoundation.nova.feature_account_impl.data.signer.signingContext.SigningContextFactory
 import io.novafoundation.nova.feature_account_impl.di.AccountFeatureModule.BindsModule
@@ -402,10 +404,12 @@ class AccountFeatureModule {
         nodeDao: NodeDao,
         secretStoreV1: SecretStoreV1,
         accountDataMigration: AccountDataMigration,
+        tronAddressBackfillMigration: TronAddressBackfillMigration,
         metaAccountDao: MetaAccountDao,
         secretsMetaAccountLocalFactory: SecretsMetaAccountLocalFactory,
         secretStoreV2: SecretStoreV2,
         accountMappers: AccountMappers,
+        bitcoinAddressBackfillMigration: BitcoinAddressBackfillMigration,
     ): AccountDataSource {
         return AccountDataSourceImpl(
             preferences,
@@ -416,10 +420,22 @@ class AccountFeatureModule {
             secretStoreV2,
             secretsMetaAccountLocalFactory,
             secretStoreV1,
-            accountDataMigration
+            accountDataMigration,
+            tronAddressBackfillMigration,
+            bitcoinAddressBackfillMigration
         )
     }
 
+    @Provides
+    @FeatureScope
+    fun provideBitcoinAddressBackfillMigration(
+        secretStoreV2: SecretStoreV2,
+        metaAccountDao: MetaAccountDao,
+        accountSecretsFactory: AccountSecretsFactory,
+    ): BitcoinAddressBackfillMigration {
+        return BitcoinAddressBackfillMigration(secretStoreV2, metaAccountDao, accountSecretsFactory)
+    }
+
     @Provides
     fun provideNodeHostValidator() = NodeHostValidator()
 
@@ -439,6 +455,16 @@ class AccountFeatureModule {
         return AccountDataMigration(preferences, encryptedPreferences, accountDao)
     }
 
+    @Provides
+    @FeatureScope
+    fun provideTronAddressBackfillMigration(
+        secretStoreV2: SecretStoreV2,
+        metaAccountDao: MetaAccountDao,
+        accountSecretsFactory: AccountSecretsFactory,
+    ): TronAddressBackfillMigration {
+        return TronAddressBackfillMigration(secretStoreV2, metaAccountDao, accountSecretsFactory)
+    }
+
     @Provides
     @FeatureScope
     fun provideExternalAccountActions(

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/DefaultMetaAccount.kt

@@ -24,6 +24,8 @@ open class DefaultMetaAccount(
     override val parentMetaId: Long?,
     override val tronAddress: ByteArray? = null,
     override val tronPublicKey: ByteArray? = null,
+    override val bitcoinAddress: ByteArray? = null,
+    override val bitcoinPublicKey: ByteArray? = null,
 ) : MetaAccount {
 
     override suspend fun supportsAddingChainAccount(chain: Chain): Boolean {
@@ -34,6 +36,7 @@ open class DefaultMetaAccount(
         return when {
             hasChainAccountIn(chain.id) -> true
             chain.isTronBased -> tronAddress != null
+            chain.isBitcoinBased -> bitcoinAddress != null
             chain.isEthereumBased -> ethereumAddress != null
             else -> substrateAccountId != null
         }
@@ -43,6 +46,7 @@ open class DefaultMetaAccount(
         return when {
             hasChainAccountIn(chain.id) -> chainAccounts.getValue(chain.id).accountId
             chain.isTronBased -> tronAddress
+            chain.isBitcoinBased -> bitcoinAddress
             chain.isEthereumBased -> ethereumAddress
             else -> substrateAccountId
         }
@@ -52,6 +56,7 @@ open class DefaultMetaAccount(
         return when {
             hasChainAccountIn(chain.id) -> chainAccounts.getValue(chain.id).publicKey
             chain.isTronBased -> tronPublicKey
+            chain.isBitcoinBased -> bitcoinPublicKey
             chain.isEthereumBased -> ethereumPublicKey
             else -> substratePublicKey
         }

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/GenericLedgerMetaAccount.kt

@@ -24,6 +24,8 @@ class GenericLedgerMetaAccount(
     private val supportedGenericLedgerChains: Set<ChainId>,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -39,7 +41,9 @@ class GenericLedgerMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ) {
 
     override suspend fun supportsAddingChainAccount(chain: Chain): Boolean {

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/LegacyLedgerMetaAccount.kt

@@ -24,6 +24,8 @@ class LegacyLedgerMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -39,7 +41,9 @@ class LegacyLedgerMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ) {
 
     override suspend fun supportsAddingChainAccount(chain: Chain): Boolean {

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/MultisigMetaAccount.kt

@@ -30,6 +30,8 @@ class RealMultisigMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -45,7 +47,9 @@ class RealMultisigMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ),
     MultisigMetaAccount {
 

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/PolkadotVaultMetaAccount.kt

@@ -22,6 +22,8 @@ class PolkadotVaultMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -37,10 +39,12 @@ class PolkadotVaultMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ) {
 
     override suspend fun supportsAddingChainAccount(chain: Chain): Boolean {
-        return !chain.isEthereumBased && !chain.isTronBased
+        return !chain.isEthereumBased && !chain.isTronBased && !chain.isBitcoinBased
     }
 }

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/RealProxiedMetaAccount.kt

@@ -24,6 +24,8 @@ internal class RealProxiedMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -39,7 +41,9 @@ internal class RealProxiedMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ),
     ProxiedMetaAccount {
 

feature-account-impl/src/main/java/io/novafoundation/nova/feature_account_impl/domain/account/model/RealSecretsMetaAccount.kt

@@ -25,6 +25,8 @@ class RealSecretsMetaAccount(
     parentMetaId: Long?,
     tronAddress: ByteArray? = null,
     tronPublicKey: ByteArray? = null,
+    bitcoinAddress: ByteArray? = null,
+    bitcoinPublicKey: ByteArray? = null,
 ) : DefaultMetaAccount(
     id = id,
     globallyUniqueId = globallyUniqueId,
@@ -40,7 +42,9 @@ class RealSecretsMetaAccount(
     chainAccounts = chainAccounts,
     parentMetaId = parentMetaId,
     tronAddress = tronAddress,
-    tronPublicKey = tronPublicKey
+    tronPublicKey = tronPublicKey,
+    bitcoinAddress = bitcoinAddress,
+    bitcoinPublicKey = bitcoinPublicKey
 ),
     SecretsMetaAccount {
 
@@ -49,7 +53,10 @@ class RealSecretsMetaAccount(
             hasChainAccountIn(chain.id) -> {
                 val cryptoType = chainAccounts.getValue(chain.id).cryptoType ?: return null
 
-                if (chain.isEthereumBased) {
+                // Tron and Bitcoin both reuse the same secp256k1 keypair/signing as Ethereum - see
+                // RealTronTransactionService/RealBitcoinTransactionService's use of
+                // Signer.sign(MultiChainEncryption.Ethereum, ...).
+                if (chain.isEthereumBased || chain.isTronBased || chain.isBitcoinBased) {
                     MultiChainEncryption.Ethereum
                 } else {
                     MultiChainEncryption.substrateFrom(cryptoType)
@@ -58,6 +65,10 @@ class RealSecretsMetaAccount(
 
             chain.isEthereumBased -> MultiChainEncryption.Ethereum
 
+            chain.isTronBased -> MultiChainEncryption.Ethereum
+
+            chain.isBitcoinBased -> MultiChainEncryption.Ethereum
+
             else -> substrateCryptoType?.let(MultiChainEncryption.Companion::substrateFrom)
         }
     }

feature-account-impl/src/test/java/io/novafoundation/nova/feature_account_impl/data/cloudBackup/RealLocalAccountsCloudBackupFacadeTest.kt

@@ -7,6 +7,8 @@ import io.novafoundation.nova.common.data.secrets.v2.ChainAccountSecrets
 import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
 import io.novafoundation.nova.common.data.secrets.v2.SecretStoreV2
 import io.novafoundation.nova.common.data.secrets.v2.entropy
+import io.novafoundation.nova.common.data.secrets.v2.tronDerivationPath
+import io.novafoundation.nova.common.data.secrets.v2.tronKeypair
 import io.novafoundation.nova.core.model.CryptoType
 import io.novafoundation.nova.core_db.dao.MetaAccountDao
 import io.novafoundation.nova.core_db.model.chain.account.ChainAccountLocal
@@ -536,6 +538,64 @@ class RealLocalAccountsCloudBackupFacadeTest {
         verifyEvent(expectedEvent)
     }
 
+    // Regression test for a wallet's Tron address/keypair being silently dropped on a cloud backup round trip:
+    // WalletPublicInfo/WalletPrivateInfo had no tron field at all until this fix, so a backup written from a
+    // wallet that genuinely had a Tron address, once applied back to local (e.g. after "clear all data" +
+    // restore, or on a fresh install created via the cloud-backup-first-wallet flow), landed with
+    // tronAddress/tronPublicKey/tronKeypair = null - found via real-device testing, not by this test.
+    @Test
+    fun shouldApplyAddAccountDiffWithTronSecrets() = runBlocking {
+        LocalAccountsMocker.setupMocks(metaAccountDao) {}
+        SecretStoreMocker.setupMocks(secretStore) {}
+
+        allChainsAreEvm(false)
+
+        val localBackup = buildTestCloudBackup {
+            publicData { }
+            privateData { }
+        }
+
+        val bytes32 = bytes32of(0)
+        val tronAddressBytes = bytes20of(1)
+        val tronDerivationPath = "//44//195//0/0/0"
+
+        val cloudBackup = buildTestCloudBackup {
+            publicData {
+                wallet(walletUUid(0)) {
+                    substrateAccountId(bytes32)
+                    substrateCryptoType(CryptoType.SR25519)
+                    substratePublicKey(bytes32)
+
+                    tronPublicKey(bytes32)
+                    tronAddress(tronAddressBytes)
+                }
+            }
+
+            privateData {
+                wallet(walletUUid(0)) {
+                    entropy(bytes32)
+
+                    substrate {
+                        seed(bytes32)
+                        keypair(KeyPairSecrets(bytes32, bytes32, bytes32))
+                    }
+
+                    tron {
+                        derivationPath(tronDerivationPath)
+                        keypair(KeyPairSecrets(bytes32, bytes32, nonce = null))
+                    }
+                }
+            }
+        }
+
+        val diff = localBackup.localVsCloudDiff(cloudBackup, BackupDiffStrategy.overwriteLocal())
+
+        facade.applyBackupDiff(diff, cloudBackup)
+
+        verify(metaAccountDao).insertMetaAccount(metaAccountWithTronAddress(tronAddressBytes))
+        verify(secretStore).putMetaAccountSecrets(eq(0), metaAccountSecretsWithTronDerivationPath(tronDerivationPath))
+    }
+
     @Test
     fun shouldApplyRemoveAccountDiff(): Unit = runBlocking {
         allChainsAreEvm(false)
@@ -1205,6 +1265,14 @@ class RealLocalAccountsCloudBackupFacadeTest {
         return argThat { it.globallyUniqueId == id }
     }
 
+    private fun metaAccountWithTronAddress(tronAddress: ByteArray): MetaAccountLocal {
+        return argThat { it.tronAddress.contentEquals(tronAddress) }
+    }
+
+    private fun metaAccountSecretsWithTronDerivationPath(derivationPath: String): EncodableStruct<MetaAccountSecrets> {
+        return argThat { it.tronDerivationPath == derivationPath && it.tronKeypair != null }
+    }
+
     private suspend fun verifyNoAdditionalSecretsInserted() {
         verify(secretStore, never()).putAdditionalMetaAccountSecret(anyLong(), any(), any())
     }

feature-account-impl/src/test/java/io/novafoundation/nova/feature_account_impl/data/repository/datasource/migration/TronAddressBackfillMigrationTest.kt

@@ -0,0 +1,192 @@
+package io.novafoundation.nova.feature_account_impl.data.repository.datasource.migration
+
+import io.novafoundation.nova.common.data.secrets.v2.KeyPairSchema
+import io.novafoundation.nova.common.data.secrets.v2.MetaAccountSecrets
+import io.novafoundation.nova.common.data.secrets.v2.SecretStoreV2
+import io.novafoundation.nova.common.data.secrets.v2.mapKeypairStructToKeypair
+import io.novafoundation.nova.common.data.secrets.v2.tronKeypair
+import io.novafoundation.nova.common.utils.invoke
+import io.novafoundation.nova.common.utils.tronAddressToAccountId
+import io.novafoundation.nova.common.utils.tronPublicKeyToAccountId
+import io.novafoundation.nova.core.model.CryptoType
+import io.novafoundation.nova.core_db.dao.MetaAccountDao
+import io.novafoundation.nova.core_db.model.chain.account.MetaAccountLocal
+import io.novafoundation.nova.feature_account_impl.data.secrets.AccountSecretsFactory
+import io.novasama.substrate_sdk_android.encrypt.json.JsonDecoder
+import io.novasama.substrate_sdk_android.encrypt.mnemonic.MnemonicCreator
+import io.novasama.substrate_sdk_android.scale.EncodableStruct
+import kotlinx.coroutines.runBlocking
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatcher
+import org.mockito.Mock
+import org.mockito.Mockito
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+import org.mockito.junit.MockitoJUnitRunner
+
+// Same guaranteed-non-null-return wrappers as RealTronTransactionServiceTest, and for the same reason: the
+// shared test_shared eq()/any() helpers crash with "eq(...) must not be null" once Mockito's genuinely-null
+// runtime return flows into a Kotlin non-null-typed parameter - see that test's class doc for the full writeup.
+private fun <T> eq(value: T): T = Mockito.eq(value) ?: value
+
+@Suppress("UNCHECKED_CAST")
+private fun <T> any(): T {
+    Mockito.any<T>()
+    return null as T
+}
+
+@Suppress("UNCHECKED_CAST")
+private fun <T> argThat(matcher: (T) -> Boolean): T {
+    Mockito.argThat(ArgumentMatcher<T> { matcher(it) })
+    return null as T
+}
+
+private fun <T> whenever(methodCall: T?) = Mockito.`when`(methodCall)
+
+/**
+ * This is the money-safety-critical half of the Tron backfill fix (see TronAddressBackfillMigration's class
+ * doc for the full context): a wrong derivation here would silently give a pre-existing wallet a Tron address
+ * it does NOT actually control, or fail to skip an account it shouldn't touch. Uses a real (non-mocked)
+ * AccountSecretsFactory so the actual BIP32/secp256k1 derivation math runs for real, and asserts against the
+ * same live-TronGrid-cross-validated reference address TronDerivationTest already established for the standard
+ * BIP39 test mnemonic, so this test and that one are pinned to the same known-good vector.
+ */
+@RunWith(MockitoJUnitRunner::class)
+class TronAddressBackfillMigrationTest {
+
+    @Mock
+    lateinit var secretStoreV2: SecretStoreV2
+
+    @Mock
+    lateinit var metaAccountDao: MetaAccountDao
+
+    @Mock
+    lateinit var jsonDecoder: JsonDecoder
+
+    private lateinit var subject: TronAddressBackfillMigration
+
+    private val testMnemonic = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+    private val expectedTronAccountId = "TUEZSdKsoDHQMeZwihtdoBiN46zxhGWYdH".tronAddressToAccountId()
+
+    @Before
+    fun setup() {
+        // Real factory, not a mock - the whole point of this test is to exercise the actual derivation.
+        val accountSecretsFactory = AccountSecretsFactory(jsonDecoder)
+        subject = TronAddressBackfillMigration(secretStoreV2, metaAccountDao, accountSecretsFactory)
+    }
+
+    @Test
+    fun `migrate should derive and persist the well-known reference Tron address for a pre-existing mnemonic account`(): Unit = runBlocking {
+        val account = secretsAccount(id = 42, substrateCryptoType = CryptoType.SR25519)
+        val secrets = accountSecrets(entropy = MnemonicCreator.fromWords(testMnemonic).entropy, tronKeypair = null)
+
+        whenever(metaAccountDao.getMetaAccounts()).thenReturn(listOf(account))
+        whenever(metaAccountDao.getMetaAccount(eq(42L))).thenReturn(account)
+        whenever(secretStoreV2.getMetaAccountSecrets(eq(42L))).thenReturn(secrets)
+
+        subject.migrate()
+
+        verify(metaAccountDao).updateMetaAccount(
+            argThat<MetaAccountLocal> { updated ->
+                updated.id == 42L && updated.tronAddress.contentEquals(expectedTronAccountId)
+            }
+        )
+
+        verify(secretStoreV2).putMetaAccountSecrets(
+            eq(42L),
+            argThat<EncodableStruct<MetaAccountSecrets>> { updatedSecrets ->
+                val tronKeypairStruct = updatedSecrets.tronKeypair
+                tronKeypairStruct != null &&
+                    mapKeypairStructToKeypair(tronKeypairStruct).publicKey.tronPublicKeyToAccountId().contentEquals(expectedTronAccountId)
+            }
+        )
+    }
+
+    @Test
+    fun `migrate should skip an account that already has a Tron keypair`(): Unit = runBlocking {
+        val account = secretsAccount(id = 7, substrateCryptoType = CryptoType.SR25519)
+        val existingTronKeypair = KeyPairSchema { keypair ->
+            keypair[KeyPairSchema.PublicKey] = ByteArray(33) { 9 }
+            keypair[KeyPairSchema.PrivateKey] = ByteArray(32) { 8 }
+            keypair[KeyPairSchema.Nonce] = null
+        }
+        val secrets = accountSecrets(entropy = MnemonicCreator.fromWords(testMnemonic).entropy, tronKeypair = existingTronKeypair)
+
+        whenever(metaAccountDao.getMetaAccounts()).thenReturn(listOf(account))
+        whenever(secretStoreV2.getMetaAccountSecrets(eq(7L))).thenReturn(secrets)
+
+        subject.migrate()
+
+        verify(metaAccountDao, never()).updateMetaAccount(any())
+        // metaId is a primitive Long parameter - same anyBoolean() reasoning applies, use anyLong().
+        verify(secretStoreV2, never()).putMetaAccountSecrets(Mockito.anyLong(), any())
+    }
+
+    @Test
+    fun `migrate should skip an account with no entropy (raw-seed import, not a mnemonic)`(): Unit = runBlocking {
+        val account = secretsAccount(id = 11, substrateCryptoType = CryptoType.SR25519)
+        val secrets = accountSecrets(entropy = null, tronKeypair = null)
+
+        whenever(metaAccountDao.getMetaAccounts()).thenReturn(listOf(account))
+        whenever(secretStoreV2.getMetaAccountSecrets(eq(11L))).thenReturn(secrets)
+
+        subject.migrate()
+
+        verify(metaAccountDao, never()).updateMetaAccount(any())
+        // metaId is a primitive Long parameter - same anyBoolean() reasoning applies, use anyLong().
+        verify(secretStoreV2, never()).putMetaAccountSecrets(Mockito.anyLong(), any())
+    }
+
+    @Test
+    fun `migrate should skip an account with no stored secrets at all (watch-only, Ledger, etc)`(): Unit = runBlocking {
+        val account = secretsAccount(id = 13, substrateCryptoType = CryptoType.SR25519)
+
+        whenever(metaAccountDao.getMetaAccounts()).thenReturn(listOf(account))
+        whenever(secretStoreV2.getMetaAccountSecrets(eq(13L))).thenReturn(null)
+
+        subject.migrate()
+
+        verify(metaAccountDao, never()).updateMetaAccount(any())
+        // metaId is a primitive Long parameter - same anyBoolean() reasoning applies, use anyLong().
+        verify(secretStoreV2, never()).putMetaAccountSecrets(Mockito.anyLong(), any())
+    }
+
+    private fun secretsAccount(id: Long, substrateCryptoType: CryptoType): MetaAccountLocal {
+        return MetaAccountLocal(
+            substratePublicKey = ByteArray(32) { 1 },
+            substrateCryptoType = substrateCryptoType,
+            substrateAccountId = ByteArray(32) { 2 },
+            ethereumPublicKey = null,
+            ethereumAddress = null,
+            name = "Test account",
+            parentMetaId = null,
+            isSelected = true,
+            position = 0,
+            type = MetaAccountLocal.Type.SECRETS,
+            status = MetaAccountLocal.Status.ACTIVE,
+            globallyUniqueId = "test-guid-$id",
+            typeExtras = null
+        ).also { it.id = id }
+    }
+
+    private fun accountSecrets(entropy: ByteArray?, tronKeypair: EncodableStruct<KeyPairSchema>?): EncodableStruct<MetaAccountSecrets> {
+        val dummySubstrateKeypair = KeyPairSchema { keypair ->
+            keypair[KeyPairSchema.PublicKey] = ByteArray(32) { 5 }
+            keypair[KeyPairSchema.PrivateKey] = ByteArray(32) { 6 }
+            keypair[KeyPairSchema.Nonce] = ByteArray(8) { 7 }
+        }
+
+        return MetaAccountSecrets(
+            substrateKeyPair = mapKeypairStructToKeypair(dummySubstrateKeypair),
+            entropy = entropy,
+            substrateSeed = null,
+            substrateDerivationPath = null,
+            ethereumKeypair = null,
+            ethereumDerivationPath = null,
+            tronKeypair = tronKeypair?.let(::mapKeypairStructToKeypair),
+            tronDerivationPath = null
+        )
+    }
+}

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/data/network/BalancesUpdateSystem.kt

@@ -39,12 +39,24 @@ class BalancesUpdateSystem(
     override fun start(): Flow<Updater.SideEffect> {
         return accountUpdateScope.invalidationFlow().flatMapLatest { metaAccount ->
             chainRegistry.currentChains.transformLatestDiffed { chain ->
+                if (chain.isTronBased) {
+                    Log.d(LOG_TAG, "TronDebug: currentChains delivered chain=${chain.id} name=${chain.name}")
+                }
                 emitAll(balancesSync(chain, metaAccount))
             }
         }.flowOn(Dispatchers.Default)
     }
 
     private suspend fun balancesSync(chain: Chain, metaAccount: MetaAccount): Flow<Updater.SideEffect> {
+        if (chain.isTronBased) {
+            Log.d(
+                LOG_TAG,
+                "TronDebug: gate check chain=${chain.id} name=${chain.name} hasAccountIn=${metaAccount.hasAccountIn(chain)} " +
+                    "connectionState=${chain.connectionState} isDisabled=${chain.connectionState.isDisabled} " +
+                    "hasSubstrateRuntime=${chain.hasSubstrateRuntime} canPerformFullSync=${chain.canPerformFullSync()}"
+            )
+        }
+
         return when {
             !metaAccount.hasAccountIn(chain) -> emptyFlow()
             chain.connectionState.isDisabled -> emptyFlow()
@@ -89,6 +101,10 @@ class BalancesUpdateSystem(
                 try {
                     updater.listenForUpdates(subscriptionBuilder, metaAccount).catch { logError(chain, it) }
                 } catch (e: Exception) {
+                    // Was silently swallowed here with zero logging - listenForUpdates() itself is a suspend
+                    // call that can throw synchronously (e.g. FullSyncPaymentUpdater.listenForUpdates() calling
+                    // requireAccountIdIn(chain)), before ever returning a flow for the .catch{} above to guard.
+                    Log.e(LOG_TAG, "listenForUpdates() threw synchronously for ${updater.javaClass.simpleName} in ${chain.name}", e)
                     emptyFlow()
                 }
             }

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/balance/common/mappers/TokenAssetMappers.kt

@@ -6,7 +6,8 @@ import io.novafoundation.nova.common.presentation.AssetIconProvider
 import io.novafoundation.nova.common.presentation.getAssetIconOrFallback
 import io.novafoundation.nova.common.utils.formatting.formatAsChange
 import io.novafoundation.nova.common.utils.orZero
-import io.novafoundation.nova.feature_account_api.data.mappers.mapChainToUi
+import io.novafoundation.nova.feature_account_api.presenatation.chain.ChainUi
+import io.novafoundation.nova.runtime.ext.displayNameWithAssetStandard
 import io.novafoundation.nova.feature_assets.R
 import io.novafoundation.nova.feature_account_api.presenatation.chain.getAssetIconOrFallback
 import io.novafoundation.nova.feature_assets.domain.common.AssetWithNetwork
@@ -90,7 +91,14 @@ class TokenAssetFormatter(
                 group.getId(),
                 mapAssetToAssetModel(it.asset, balance(it.balanceWithOffChain)),
                 assetIconProvider.getAssetIconOrFallback(it.asset.token.configuration),
-                mapChainToUi(it.chain)
+                // Not mapChainToUi() here - this row's subtitle needs to disambiguate which issuance of the
+                // token this is (e.g. "Ethereum (ERC-20)" vs "Tron (TRC-20)"), which a bare chain name alone
+                // doesn't when multiple ecosystems share the same symbol (USDT, USDC, etc.).
+                ChainUi(
+                    id = it.chain.id,
+                    name = it.chain.displayNameWithAssetStandard(),
+                    icon = it.chain.icon
+                )
             )
         }
     }

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/BridgeFragment.kt

@@ -5,11 +5,14 @@ import android.text.TextWatcher
 import android.view.View
 import io.novafoundation.nova.common.base.BaseFragment
 import io.novafoundation.nova.common.di.FeatureUtils
+import io.novafoundation.nova.common.utils.setVisible
+import io.novafoundation.nova.common.view.AlertView
 import io.novafoundation.nova.common.view.setState
 import io.novafoundation.nova.feature_assets.R
 import io.novafoundation.nova.feature_assets.databinding.FragmentBridgeBinding
 import io.novafoundation.nova.feature_assets.di.AssetsFeatureApi
 import io.novafoundation.nova.feature_assets.di.AssetsFeatureComponent
+import io.novafoundation.nova.feature_wallet_api.presentation.mixin.amountChooser.MaxActionAvailability
 
 class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
 
@@ -18,26 +21,29 @@ class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
     override fun initViews() {
         binder.bridgeToolbar.setHomeButtonListener { viewModel.backClicked() }
 
-        // Pair selector
+        binder.bridgeToCard.setEditable(false)
-        binder.bridgePairDotHez.setOnClickListener {
+
-            viewModel.setPair(BridgePair.DOT_HEZ)
+        // Tapping the "from" card opens the pair picker - replaces the old segmented pair buttons
+        binder.bridgeFromCard.setCardClickListener {
+            val options = viewModel.pairOptions.value.orEmpty()
+            if (options.isNotEmpty()) {
+                BridgePairListBottomSheet(requireContext(), options) { selected ->
+                    viewModel.setPair(selected.pair)
+                }.show()
+            }
         }
 
-        binder.bridgePairUsdt.setOnClickListener {
+        // One-tap direction flip - replaces the old segmented direction buttons
-            viewModel.setPair(BridgePair.USDT)
+        binder.bridgeFlipButton.setOnClickListener {
-        }
+            when (viewModel.direction.value) {
-
+                BridgeDirection.DOT_TO_HEZ, BridgeDirection.USDT_TO_WUSDT -> viewModel.setDirectionRight()
-        // Direction toggle
+                BridgeDirection.HEZ_TO_DOT, BridgeDirection.WUSDT_TO_USDT -> viewModel.setDirectionLeft()
-        binder.bridgeDirectionLeft.setOnClickListener {
+                null -> Unit
-            viewModel.setDirectionLeft()
+            }
-        }
-
-        binder.bridgeDirectionRight.setOnClickListener {
-            viewModel.setDirectionRight()
         }
 
         // Amount input
-        binder.bridgeFromAmount.addTextChangedListener(object : TextWatcher {
+        binder.bridgeFromCard.amountInput.addTextChangedListener(object : TextWatcher {
             override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
             override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
             override fun afterTextChanged(s: Editable?) {
@@ -46,6 +52,10 @@ class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
             }
         })
 
+        binder.bridgeFromMaxAmount.setMaxActionAvailability(
+            MaxActionAvailability.Available { viewModel.maxClicked() }
+        )
+
         // Swap button
         binder.bridgeSwapButton.setOnClickListener {
             viewModel.swapClicked()
@@ -74,16 +84,16 @@ class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
     }
 
     override fun subscribe(viewModel: BridgeViewModel) {
-        viewModel.pair.observe { pair ->
+        viewModel.fromCard.observe { model ->
-            updatePairUI(pair)
+            binder.bridgeFromCard.setModel(model)
         }
 
-        viewModel.direction.observe { direction ->
+        viewModel.toCard.observe { model ->
-            updateDirectionUI(direction)
+            binder.bridgeToCard.setModel(model)
         }
 
         viewModel.outputAmount.observe { output ->
-            binder.bridgeToAmount.text = output
+            binder.bridgeToCard.setAmountText(output)
         }
 
         viewModel.exchangeRateText.observe { rate ->
@@ -99,20 +109,18 @@ class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
         }
 
         viewModel.showWarning.observe { show ->
-            binder.bridgeHezToDotWarning.visibility = if (show) View.VISIBLE else View.GONE
+            binder.bridgeWarningAlert.setVisible(show)
         }
 
         viewModel.warningBlocked.observe { blocked ->
-            if (blocked) {
+            binder.bridgeWarningAlert.setStylePreset(
-                binder.bridgeHezToDotWarning.setBackgroundColor(resources.getColor(R.color.error_block_background, null))
+                if (blocked) AlertView.StylePreset.ERROR else AlertView.StylePreset.WARNING
-            } else {
+            )
-                binder.bridgeHezToDotWarning.setBackgroundColor(resources.getColor(R.color.warning_block_background, null))
-            }
         }
 
         viewModel.warningText.observe { text ->
             if (text.isNotEmpty()) {
-                binder.bridgeHezToDotWarning.text = text
+                binder.bridgeWarningAlert.setMessage(text)
             }
         }
 
@@ -136,65 +144,17 @@ class BridgeFragment : BaseFragment<BridgeViewModel, FragmentBridgeBinding>() {
         viewModel.signButtonLabel.observe { label ->
             binder.bridgeSignButton.text = label
         }
-    }
 
-    private fun updatePairUI(pair: BridgePair) {
+        viewModel.maxAmountDisplay.observe { display ->
-        when (pair) {
+            binder.bridgeFromMaxAmount.setMaxAmountDisplay(display)
-            BridgePair.DOT_HEZ -> {
-                binder.bridgePairDotHez.setBackgroundResource(R.drawable.bg_button_primary)
-                binder.bridgePairDotHez.setTextColor(resources.getColor(R.color.text_primary, null))
-                binder.bridgePairUsdt.background = null
-                binder.bridgePairUsdt.setTextColor(resources.getColor(R.color.text_secondary, null))
-            }
-            BridgePair.USDT -> {
-                binder.bridgePairUsdt.setBackgroundResource(R.drawable.bg_button_primary)
-                binder.bridgePairUsdt.setTextColor(resources.getColor(R.color.text_primary, null))
-                binder.bridgePairDotHez.background = null
-                binder.bridgePairDotHez.setTextColor(resources.getColor(R.color.text_secondary, null))
-            }
-        }
-    }
-
-    private fun updateDirectionUI(direction: BridgeDirection) {
-        val isLeft = direction == BridgeDirection.DOT_TO_HEZ || direction == BridgeDirection.USDT_TO_WUSDT
-
-        if (isLeft) {
-            binder.bridgeDirectionLeft.setBackgroundResource(R.drawable.bg_button_primary)
-            binder.bridgeDirectionLeft.setTextColor(resources.getColor(R.color.text_primary, null))
-            binder.bridgeDirectionRight.background = null
-            binder.bridgeDirectionRight.setTextColor(resources.getColor(R.color.text_secondary, null))
-        } else {
-            binder.bridgeDirectionRight.setBackgroundResource(R.drawable.bg_button_primary)
-            binder.bridgeDirectionRight.setTextColor(resources.getColor(R.color.text_primary, null))
-            binder.bridgeDirectionLeft.background = null
-            binder.bridgeDirectionLeft.setTextColor(resources.getColor(R.color.text_secondary, null))
         }
 
-        when (direction) {
+        viewModel.insufficientBalanceError.observe { error ->
-            BridgeDirection.DOT_TO_HEZ -> {
+            binder.bridgeFromCard.setError(error)
-                binder.bridgeDirectionLeft.text = "DOT → HEZ"
+        }
-                binder.bridgeDirectionRight.text = "HEZ → DOT"
+
-                binder.bridgeFromToken.text = "DOT"
+        viewModel.fillAmountEvent.observeEvent { amount ->
-                binder.bridgeToToken.text = "HEZ"
+            binder.bridgeFromCard.amountInput.setText(amount)
-            }
-            BridgeDirection.HEZ_TO_DOT -> {
-                binder.bridgeDirectionLeft.text = "DOT → HEZ"
-                binder.bridgeDirectionRight.text = "HEZ → DOT"
-                binder.bridgeFromToken.text = "HEZ"
-                binder.bridgeToToken.text = "DOT"
-            }
-            BridgeDirection.USDT_TO_WUSDT -> {
-                binder.bridgeDirectionLeft.text = "USDT(Pol) → USDT(Pez)"
-                binder.bridgeDirectionRight.text = "USDT(Pez) → USDT(Pol)"
-                binder.bridgeFromToken.text = "USDT"
-                binder.bridgeToToken.text = "USDT"
-            }
-            BridgeDirection.WUSDT_TO_USDT -> {
-                binder.bridgeDirectionLeft.text = "USDT(Pol) → USDT(Pez)"
-                binder.bridgeDirectionRight.text = "USDT(Pez) → USDT(Pol)"
-                binder.bridgeFromToken.text = "USDT"
-                binder.bridgeToToken.text = "USDT"
-            }
         }
     }
 }

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/BridgePairListBottomSheet.kt

@@ -0,0 +1,68 @@
+package io.novafoundation.nova.feature_assets.presentation.bridge
+
+import android.content.Context
+import android.os.Bundle
+import androidx.recyclerview.widget.DiffUtil
+import coil.ImageLoader
+import io.novafoundation.nova.common.di.FeatureUtils
+import io.novafoundation.nova.common.utils.images.Icon
+import io.novafoundation.nova.common.utils.images.setIconOrMakeGone
+import io.novafoundation.nova.common.utils.inflater
+import io.novafoundation.nova.common.view.bottomSheet.list.dynamic.DynamicListBottomSheet
+import io.novafoundation.nova.common.view.bottomSheet.list.dynamic.DynamicListSheetAdapter
+import io.novafoundation.nova.common.view.bottomSheet.list.dynamic.HolderCreator
+import io.novafoundation.nova.feature_assets.R
+import io.novafoundation.nova.feature_assets.databinding.ItemBridgePairListBinding
+
+data class BridgePairUi(
+    val pair: BridgePair,
+    val icon: Icon,
+    val title: String
+)
+
+class BridgePairListBottomSheet(
+    context: Context,
+    data: List<BridgePairUi>,
+    onClicked: (BridgePairUi) -> Unit
+) : DynamicListBottomSheet<BridgePairUi>(
+    context,
+    Payload(data),
+    BridgePairDiffCallback,
+    onClicked = { _, item -> onClicked(item) }
+) {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        setTitle(R.string.bridge_title)
+    }
+
+    override fun holderCreator(): HolderCreator<BridgePairUi> = {
+        BridgePairListHolder(ItemBridgePairListBinding.inflate(it.inflater(), it, false))
+    }
+}
+
+class BridgePairListHolder(
+    private val binder: ItemBridgePairListBinding
+) : DynamicListSheetAdapter.Holder<BridgePairUi>(binder.root) {
+
+    private val imageLoader: ImageLoader by lazy(LazyThreadSafetyMode.NONE) {
+        FeatureUtils.getCommonApi(binder.root.context).imageLoader()
+    }
+
+    override fun bind(item: BridgePairUi, isSelected: Boolean, handler: DynamicListSheetAdapter.Handler<BridgePairUi>) {
+        binder.itemBridgePairIcon.setIconOrMakeGone(item.icon, imageLoader)
+        binder.itemBridgePairTitle.text = item.title
+        binder.root.setOnClickListener { handler.itemClicked(item) }
+    }
+}
+
+private object BridgePairDiffCallback : DiffUtil.ItemCallback<BridgePairUi>() {
+    override fun areItemsTheSame(oldItem: BridgePairUi, newItem: BridgePairUi): Boolean {
+        return oldItem.pair == newItem.pair
+    }
+
+    override fun areContentsTheSame(oldItem: BridgePairUi, newItem: BridgePairUi): Boolean {
+        return true
+    }
+}

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/BridgeViewModel.kt

@@ -3,9 +3,14 @@ package io.novafoundation.nova.feature_assets.presentation.bridge
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import io.novafoundation.nova.common.base.BaseViewModel
+import io.novafoundation.nova.common.presentation.AssetIconProvider
 import io.novafoundation.nova.common.resources.ResourceManager
+import io.novafoundation.nova.common.utils.Event
+import io.novafoundation.nova.common.utils.images.Icon
 import io.novafoundation.nova.common.view.ButtonState
+import io.novafoundation.nova.feature_account_api.presenatation.chain.getAssetIconOrFallback
 import io.novafoundation.nova.feature_assets.R
+import io.novafoundation.nova.feature_assets.domain.WalletInteractor
 import io.novafoundation.nova.feature_assets.domain.bridge.multisig.BridgeMultisigInteractor
 import io.novafoundation.nova.feature_assets.domain.bridge.multisig.BridgeSignerState
 import io.novafoundation.nova.feature_assets.presentation.AssetsRouter
@@ -13,9 +18,11 @@ import io.novafoundation.nova.feature_assets.presentation.send.amount.SendPayloa
 import io.novafoundation.nova.feature_wallet_api.presentation.model.AssetPayload
 import io.novafoundation.nova.runtime.ext.ChainGeneses
 import io.novafoundation.nova.runtime.ext.addressOf
+import io.novafoundation.nova.runtime.ext.displayNameWithAssetStandard
 import io.novafoundation.nova.runtime.multiNetwork.ChainRegistry
 import io.novasama.substrate_sdk_android.ss58.SS58Encoder.toAccountId
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.json.JSONObject
@@ -27,6 +34,8 @@ class BridgeViewModel(
     private val router: AssetsRouter,
     private val resourceManager: ResourceManager,
     private val chainRegistry: ChainRegistry,
+    private val assetIconProvider: AssetIconProvider,
+    private val walletInteractor: WalletInteractor,
     private val bridgeMultisigInteractor: BridgeMultisigInteractor
 ) : BaseViewModel() {
 
@@ -91,15 +100,37 @@ class BridgeViewModel(
     private val _signButtonLabel = MutableLiveData("")
     val signButtonLabel: LiveData<String> = _signButtonLabel
 
+    private val _fromCard = MutableLiveData<BridgeAssetCardUi>()
+    val fromCard: LiveData<BridgeAssetCardUi> = _fromCard
+
+    private val _toCard = MutableLiveData<BridgeAssetCardUi>()
+    val toCard: LiveData<BridgeAssetCardUi> = _toCard
+
+    private val _pairOptions = MutableLiveData<List<BridgePairUi>>(emptyList())
+    val pairOptions: LiveData<List<BridgePairUi>> = _pairOptions
+
+    private val _maxAmountDisplay = MutableLiveData<String?>(null)
+    val maxAmountDisplay: LiveData<String?> = _maxAmountDisplay
+
+    private val _insufficientBalanceError = MutableLiveData<String?>(null)
+    val insufficientBalanceError: LiveData<String?> = _insufficientBalanceError
+
+    private val _fillAmountEvent = MutableLiveData<Event<String>>()
+    val fillAmountEvent: LiveData<Event<String>> = _fillAmountEvent
+
     private var currentAmount: Double = 0.0
     private var dotToHezRate: Double = FALLBACK_RATE
     private var isHezToDotActive: Boolean = false
     private var isWusdtToUsdtActive: Boolean = false
+    private var availableBalance: BigDecimal = BigDecimal.ZERO
+    private var balanceJob: Job? = null
 
     init {
         fetchExchangeRate()
         fetchBridgeStatus()
         refreshSignerState()
+        updateCards()
+        loadPairOptions()
     }
 
     fun setPair(newPair: BridgePair) {
@@ -113,6 +144,7 @@ class BridgeViewModel(
             updateUI()
             calculateOutput()
             updateWarningState()
+            updateCards()
         }
     }
 
@@ -127,6 +159,7 @@ class BridgeViewModel(
             updateUI()
             calculateOutput()
             updateWarningState()
+            updateCards()
         }
     }
 
@@ -141,15 +174,21 @@ class BridgeViewModel(
             updateUI()
             calculateOutput()
             updateWarningState()
+            updateCards()
         }
     }
 
     fun setAmount(amount: Double) {
         currentAmount = amount
         calculateOutput()
+        updateInsufficientBalanceState()
         updateButtonState()
     }
 
+    fun maxClicked() {
+        _fillAmountEvent.value = Event(availableBalance.stripTrailingZeros().toPlainString())
+    }
+
     fun swapClicked() {
         val dir = _direction.value ?: return
         if (currentAmount <= 0) return
@@ -329,12 +368,21 @@ class BridgeViewModel(
         _buttonState.value = when {
             currentAmount <= 0 -> ButtonState.DISABLED
             currentAmount < minimum -> ButtonState.DISABLED
+            BigDecimal.valueOf(currentAmount) > availableBalance -> ButtonState.DISABLED
             dir == BridgeDirection.HEZ_TO_DOT && !isHezToDotActive -> ButtonState.DISABLED
             dir == BridgeDirection.WUSDT_TO_USDT && !isWusdtToUsdtActive -> ButtonState.DISABLED
             else -> ButtonState.NORMAL
         }
     }
 
+    private fun updateInsufficientBalanceState() {
+        _insufficientBalanceError.value = if (currentAmount > 0 && BigDecimal.valueOf(currentAmount) > availableBalance) {
+            resourceManager.getString(R.string.bridge_insufficient_balance)
+        } else {
+            null
+        }
+    }
+
     fun refreshBridgeStatus() {
         fetchBridgeStatus()
         refreshSignerState()
@@ -388,4 +436,81 @@ class BridgeViewModel(
             }
         }
     }
+
+    private fun updateCards() {
+        val dir = _direction.value ?: return
+
+        // Same chainId/assetId mapping already used by swapClicked() to resolve the origin side -
+        // mirrored here (plus its destination counterpart) purely to display logos/names, no new business rule.
+        val originChainId = when (dir) {
+            BridgeDirection.DOT_TO_HEZ, BridgeDirection.USDT_TO_WUSDT -> POLKADOT_ASSET_HUB_ID
+            BridgeDirection.HEZ_TO_DOT, BridgeDirection.WUSDT_TO_USDT -> PEZKUWI_ASSET_HUB_ID
+        }
+        val destChainId = when (dir) {
+            BridgeDirection.DOT_TO_HEZ, BridgeDirection.USDT_TO_WUSDT -> PEZKUWI_ASSET_HUB_ID
+            BridgeDirection.HEZ_TO_DOT, BridgeDirection.WUSDT_TO_USDT -> POLKADOT_ASSET_HUB_ID
+        }
+        val originAssetId = when (dir) {
+            BridgeDirection.DOT_TO_HEZ, BridgeDirection.HEZ_TO_DOT -> UTILITY_ASSET_ID
+            BridgeDirection.USDT_TO_WUSDT -> POLKADOT_USDT_ASSET_ID
+            BridgeDirection.WUSDT_TO_USDT -> PEZKUWI_USDT_ASSET_ID
+        }
+        val destAssetId = when (dir) {
+            BridgeDirection.DOT_TO_HEZ, BridgeDirection.HEZ_TO_DOT -> UTILITY_ASSET_ID
+            BridgeDirection.USDT_TO_WUSDT -> PEZKUWI_USDT_ASSET_ID
+            BridgeDirection.WUSDT_TO_USDT -> POLKADOT_USDT_ASSET_ID
+        }
+
+        launch {
+            _fromCard.value = cardUiFor(originChainId, originAssetId)
+            _toCard.value = cardUiFor(destChainId, destAssetId)
+        }
+
+        observeOriginBalance(originChainId, originAssetId)
+    }
+
+    private fun observeOriginBalance(chainId: String, assetId: Int) {
+        balanceJob?.cancel()
+        balanceJob = launch {
+            walletInteractor.assetFlow(chainId, assetId).collect { asset ->
+                availableBalance = asset.transferable
+                _maxAmountDisplay.postValue(
+                    "${availableBalance.setScale(6, RoundingMode.DOWN).stripTrailingZeros().toPlainString()} ${asset.token.configuration.symbol.value}"
+                )
+                updateInsufficientBalanceState()
+                updateButtonState()
+            }
+        }
+    }
+
+    private fun loadPairOptions() {
+        launch {
+            val dotHezIcon = cardUiFor(POLKADOT_ASSET_HUB_ID, UTILITY_ASSET_ID).assetIcon
+            val usdtIcon = cardUiFor(POLKADOT_ASSET_HUB_ID, POLKADOT_USDT_ASSET_ID).assetIcon
+
+            _pairOptions.value = listOf(
+                BridgePairUi(BridgePair.DOT_HEZ, dotHezIcon, resourceManager.getString(R.string.bridge_pair_dot_hez)),
+                BridgePairUi(BridgePair.USDT, usdtIcon, resourceManager.getString(R.string.bridge_pair_usdt))
+            )
+        }
+    }
+
+    private suspend fun cardUiFor(chainId: String, assetId: Int): BridgeAssetCardUi {
+        val chain = chainRegistry.getChain(chainId)
+        val asset = chain.assetsById.getValue(assetId)
+
+        return BridgeAssetCardUi(
+            assetIcon = assetIconProvider.getAssetIconOrFallback(asset),
+            chainIconUrl = chain.icon,
+            symbol = asset.symbol.value,
+            chainName = chain.displayNameWithAssetStandard()
+        )
+    }
 }
+
+data class BridgeAssetCardUi(
+    val assetIcon: Icon,
+    val chainIconUrl: String?,
+    val symbol: String,
+    val chainName: String
+)

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/di/BridgeModule.kt

@@ -8,9 +8,11 @@ import dagger.Provides
 import dagger.multibindings.IntoMap
 import io.novafoundation.nova.common.di.viewmodel.ViewModelKey
 import io.novafoundation.nova.common.di.viewmodel.ViewModelModule
+import io.novafoundation.nova.common.presentation.AssetIconProvider
 import io.novafoundation.nova.common.resources.ResourceManager
 import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicService
 import io.novafoundation.nova.feature_account_api.domain.interfaces.SelectedAccountUseCase
+import io.novafoundation.nova.feature_assets.domain.WalletInteractor
 import io.novafoundation.nova.feature_assets.domain.bridge.multisig.BridgeMultisigInteractor
 import io.novafoundation.nova.feature_assets.domain.bridge.multisig.RealBridgeMultisigInteractor
 import io.novafoundation.nova.feature_assets.presentation.AssetsRouter
@@ -40,9 +42,11 @@ class BridgeModule {
         router: AssetsRouter,
         resourceManager: ResourceManager,
         chainRegistry: ChainRegistry,
+        assetIconProvider: AssetIconProvider,
+        walletInteractor: WalletInteractor,
         bridgeMultisigInteractor: BridgeMultisigInteractor
     ): ViewModel {
-        return BridgeViewModel(router, resourceManager, chainRegistry, bridgeMultisigInteractor)
+        return BridgeViewModel(router, resourceManager, chainRegistry, assetIconProvider, walletInteractor, bridgeMultisigInteractor)
     }
 
     @Provides

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/bridge/view/BridgeAssetInputView.kt

@@ -0,0 +1,76 @@
+package io.novafoundation.nova.feature_assets.presentation.bridge.view
+
+import android.content.Context
+import android.util.AttributeSet
+import android.widget.EditText
+import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.core.view.isVisible
+import coil.ImageLoader
+import io.novafoundation.nova.common.di.FeatureUtils
+import io.novafoundation.nova.common.utils.WithContextExtensions
+import io.novafoundation.nova.common.utils.images.asUrlIcon
+import io.novafoundation.nova.common.utils.images.setIconOrMakeGone
+import io.novafoundation.nova.common.utils.inflater
+import io.novafoundation.nova.common.utils.setVisible
+import io.novafoundation.nova.common.view.shape.getInputBackground
+import io.novafoundation.nova.common.view.shape.getInputBackgroundError
+import io.novafoundation.nova.feature_account_api.presenatation.chain.setTokenIcon
+import io.novafoundation.nova.feature_assets.databinding.ViewBridgeAssetInputBinding
+import io.novafoundation.nova.feature_assets.presentation.bridge.BridgeAssetCardUi
+
+class BridgeAssetInputView @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = 0
+) : ConstraintLayout(context, attrs, defStyleAttr),
+    WithContextExtensions by WithContextExtensions(context) {
+
+    private val binder = ViewBridgeAssetInputBinding.inflate(inflater(), this)
+
+    val amountInput: EditText
+        get() = binder.bridgeAssetInputField
+
+    private val imageLoader: ImageLoader by lazy(LazyThreadSafetyMode.NONE) {
+        FeatureUtils.getCommonApi(context).imageLoader()
+    }
+
+    init {
+        binder.bridgeAssetInputContainer.background = context.getInputBackground()
+    }
+
+    fun setCardClickListener(listener: OnClickListener) {
+        binder.bridgeAssetInputContainer.setOnClickListener(listener)
+        binder.bridgeAssetInputChevron.isVisible = true
+    }
+
+    fun setEditable(editable: Boolean) {
+        amountInput.isFocusable = editable
+        amountInput.isFocusableInTouchMode = editable
+        amountInput.isClickable = editable
+        amountInput.isCursorVisible = editable
+    }
+
+    fun setAmountText(text: CharSequence) {
+        if (amountInput.text?.toString() != text.toString()) {
+            amountInput.setText(text)
+        }
+    }
+
+    fun setModel(model: BridgeAssetCardUi) {
+        binder.bridgeAssetInputImage.setTokenIcon(model.assetIcon, imageLoader)
+        binder.bridgeAssetInputToken.text = model.symbol
+        binder.bridgeAssetInputSubtitle.text = model.chainName
+        binder.bridgeAssetInputSubtitleImage.setIconOrMakeGone(model.chainIconUrl?.asUrlIcon(), imageLoader)
+    }
+
+    fun setError(message: String?) {
+        binder.bridgeAssetInputContainer.background = if (message != null) {
+            context.getInputBackgroundError()
+        } else {
+            context.getInputBackground()
+        }
+
+        binder.bridgeAssetInputError.text = message
+        binder.bridgeAssetInputError.setVisible(message != null)
+    }
+}

feature-assets/src/main/java/io/novafoundation/nova/feature_assets/presentation/flow/network/NetworkFlowViewModel.kt

@@ -16,6 +16,7 @@ import io.novafoundation.nova.feature_assets.presentation.flow.network.model.Net
 import io.novafoundation.nova.feature_wallet_api.presentation.formatters.amount.AmountFormatter
 import io.novafoundation.nova.feature_wallet_api.presentation.formatters.amount.formatAmountToAmountModel
 import io.novafoundation.nova.feature_wallet_api.presentation.formatters.amount.model.AmountConfig
+import io.novafoundation.nova.runtime.ext.displayNameWithAssetStandard
 import io.novafoundation.nova.runtime.multiNetwork.ChainRegistry
 import io.novafoundation.nova.runtime.multiNetwork.asset
 import kotlinx.coroutines.flow.Flow
@@ -73,7 +74,7 @@ abstract class NetworkFlowViewModel(
                 NetworkFlowRvItem(
                     it.chain.id,
                     it.asset.token.configuration.id,
-                    it.chain.name,
+                    it.chain.displayNameWithAssetStandard(),
                     it.chain.icon,
                     amountFormatter.formatAmountToAmountModel(
                         amount = getAssetBalance(it).amount,

feature-assets/src/main/res/layout/fragment_bridge.xml

@@ -25,212 +25,65 @@
             android:orientation="vertical"
             android:padding="16dp">
 
-            <!-- Pair Selector -->
             <LinearLayout
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:layout_marginBottom="8dp"
+                android:gravity="center_vertical"
-                android:background="@drawable/bg_primary_list_item"
+                android:orientation="horizontal">
-                android:orientation="horizontal"
-                android:padding="4dp">
 
                 <TextView
-                    android:id="@+id/bridgePairDotHez"
+                    android:id="@+id/bridgeFromLabel"
+                    style="@style/TextAppearance.NovaFoundation.Regular.Footnote"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
                     android:layout_weight="1"
-                    android:background="@drawable/bg_button_primary"
+                    android:text="@string/bridge_you_send"
-                    android:gravity="center"
+                    android:textColor="@color/text_secondary" />
-                    android:padding="10dp"
-                    android:text="DOT / HEZ"
-                    android:textColor="@color/text_primary"
-                    android:textSize="13sp"
-                    android:textStyle="bold" />
 
-                <TextView
+                <io.novafoundation.nova.feature_wallet_api.presentation.view.amount.MaxAmountView
-                    android:id="@+id/bridgePairUsdt"
+                    android:id="@+id/bridgeFromMaxAmount"
-                    android:layout_width="0dp"
+                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
+                    android:layout_height="wrap_content" />
-                    android:layout_weight="1"
-                    android:gravity="center"
-                    android:padding="10dp"
-                    android:text="USDT"
-                    android:textColor="@color/text_secondary"
-                    android:textSize="13sp" />
 
             </LinearLayout>
 
-            <!-- Direction Toggle -->
+            <io.novafoundation.nova.feature_assets.presentation.bridge.view.BridgeAssetInputView
-            <LinearLayout
+                android:id="@+id/bridgeFromCard"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:layout_marginBottom="16dp"
+                android:layout_marginTop="8dp" />
-                android:background="@drawable/bg_primary_list_item"
-                android:orientation="horizontal"
-                android:padding="4dp">
 
-                <TextView
-                    android:id="@+id/bridgeDirectionLeft"
-                    android:layout_width="0dp"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:background="@drawable/bg_button_primary"
-                    android:gravity="center"
-                    android:padding="12dp"
-                    android:text="DOT → HEZ"
-                    android:textColor="@color/text_primary"
-                    android:textSize="14sp"
-                    android:textStyle="bold" />
-
-                <TextView
-                    android:id="@+id/bridgeDirectionRight"
-                    android:layout_width="0dp"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:gravity="center"
-                    android:padding="12dp"
-                    android:text="HEZ → DOT"
-                    android:textColor="@color/text_secondary"
-                    android:textSize="14sp" />
-
-            </LinearLayout>
-
-            <!-- From Section -->
-            <com.google.android.material.card.MaterialCardView
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:layout_marginBottom="8dp"
-                app:cardBackgroundColor="@color/block_background"
-                app:cardCornerRadius="12dp"
-                app:cardElevation="0dp">
-
-                <LinearLayout
-                    android:layout_width="match_parent"
-                    android:layout_height="wrap_content"
-                    android:orientation="vertical"
-                    android:padding="16dp">
-
-                    <TextView
-                        android:id="@+id/bridgeFromLabel"
-                        android:layout_width="wrap_content"
-                        android:layout_height="wrap_content"
-                        android:text="@string/bridge_you_send"
-                        android:textColor="@color/text_secondary"
-                        android:textSize="12sp" />
-
-                    <LinearLayout
-                        android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
-                        android:layout_marginTop="8dp"
-                        android:gravity="center_vertical"
-                        android:orientation="horizontal">
-
-                        <EditText
-                            android:id="@+id/bridgeFromAmount"
-                            android:layout_width="0dp"
-                            android:layout_height="wrap_content"
-                            android:layout_weight="1"
-                            android:background="@null"
-                            android:hint="0.0"
-                            android:inputType="numberDecimal"
-                            android:textColor="@color/text_primary"
-                            android:textColorHint="@color/text_secondary"
-                            android:textSize="32sp"
-                            android:textStyle="bold" />
-
-                        <TextView
-                            android:id="@+id/bridgeFromToken"
-                            android:layout_width="wrap_content"
-                            android:layout_height="wrap_content"
-                            android:text="DOT"
-                            android:textColor="@color/text_primary"
-                            android:textSize="20sp"
-                            android:textStyle="bold" />
-
-                    </LinearLayout>
-
-                    <TextView
-                        android:id="@+id/bridgeFromBalance"
-                        android:layout_width="wrap_content"
-                        android:layout_height="wrap_content"
-                        android:layout_marginTop="4dp"
-                        android:textColor="@color/text_secondary"
-                        android:textSize="12sp"
-                        tools:text="Balance: 10.5 DOT" />
-
-                </LinearLayout>
-
-            </com.google.android.material.card.MaterialCardView>
-
-            <!-- Swap Icon -->
             <ImageView
+                android:id="@+id/bridgeFlipButton"
                 android:layout_width="40dp"
                 android:layout_height="40dp"
                 android:layout_gravity="center"
                 android:layout_marginVertical="4dp"
+                android:background="?attr/selectableItemBackgroundBorderless"
                 android:padding="8dp"
-                android:src="@drawable/ic_bridge"
+                android:scaleType="centerInside"
-                app:tint="@color/icon_secondary" />
+                android:src="@drawable/ic_flip_swap" />
 
-            <!-- To Section -->
+            <TextView
-            <com.google.android.material.card.MaterialCardView
+                android:id="@+id/bridgeToLabel"
+                style="@style/TextAppearance.NovaFoundation.Regular.Footnote"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="4dp"
+                android:text="@string/bridge_you_receive"
+                android:textColor="@color/text_secondary" />
+
+            <io.novafoundation.nova.feature_assets.presentation.bridge.view.BridgeAssetInputView
+                android:id="@+id/bridgeToCard"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:layout_marginBottom="16dp"
+                android:layout_marginTop="8dp" />
-                app:cardBackgroundColor="@color/block_background"
-                app:cardCornerRadius="12dp"
-                app:cardElevation="0dp">
-
-                <LinearLayout
-                    android:layout_width="match_parent"
-                    android:layout_height="wrap_content"
-                    android:orientation="vertical"
-                    android:padding="16dp">
-
-                    <TextView
-                        android:id="@+id/bridgeToLabel"
-                        android:layout_width="wrap_content"
-                        android:layout_height="wrap_content"
-                        android:text="@string/bridge_you_receive"
-                        android:textColor="@color/text_secondary"
-                        android:textSize="12sp" />
-
-                    <LinearLayout
-                        android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
-                        android:layout_marginTop="8dp"
-                        android:gravity="center_vertical"
-                        android:orientation="horizontal">
-
-                        <TextView
-                            android:id="@+id/bridgeToAmount"
-                            android:layout_width="0dp"
-                            android:layout_height="wrap_content"
-                            android:layout_weight="1"
-                            android:text="0.0"
-                            android:textColor="@color/text_primary"
-                            android:textSize="32sp"
-                            android:textStyle="bold" />
-
-                        <TextView
-                            android:id="@+id/bridgeToToken"
-                            android:layout_width="wrap_content"
-                            android:layout_height="wrap_content"
-                            android:text="HEZ"
-                            android:textColor="@color/text_primary"
-                            android:textSize="20sp"
-                            android:textStyle="bold" />
-
-                    </LinearLayout>
-
-                </LinearLayout>
-
-            </com.google.android.material.card.MaterialCardView>
 
             <!-- Rate Info -->
             <com.google.android.material.card.MaterialCardView
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
                 app:cardBackgroundColor="@color/block_background"
                 app:cardCornerRadius="12dp"
                 app:cardElevation="0dp">
@@ -317,18 +170,14 @@
 
             </com.google.android.material.card.MaterialCardView>
 
-            <!-- Warning for HEZ to DOT -->
+            <!-- Warning for HEZ to DOT / USDT liquidity -->
-            <TextView
+            <io.novafoundation.nova.common.view.AlertView
-                android:id="@+id/bridgeHezToDotWarning"
+                android:id="@+id/bridgeWarningAlert"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_marginTop="16dp"
-                android:background="@drawable/bg_warning"
+                android:visibility="gone"
-                android:padding="12dp"
+                app:alertMode="warning" />
-                android:text="@string/bridge_hez_to_dot_note"
-                android:textColor="@color/text_warning"
-                android:textSize="12sp"
-                android:visibility="gone" />
 
             <!-- Multisig signatory-only bridge allowance sign button. Only visible to a wallet
                  that is one of the bridge multisig's 5 known signatories. -->

feature-assets/src/main/res/layout/item_bridge_pair_list.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?attr/selectableItemBackground"
+    android:gravity="center_vertical"
+    android:orientation="horizontal"
+    android:paddingHorizontal="16dp"
+    android:paddingVertical="12dp">
+
+    <ImageView
+        android:id="@+id/itemBridgePairIcon"
+        android:layout_width="32dp"
+        android:layout_height="32dp"
+        android:background="@drawable/bg_token_container"
+        android:scaleType="centerInside"
+        tools:src="@drawable/ic_pezkuwi_logo" />
+
+    <TextView
+        android:id="@+id/itemBridgePairTitle"
+        style="@style/TextAppearance.NovaFoundation.SemiBold.Body"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="12dp"
+        android:textColor="@color/text_primary"
+        tools:text="HEZ ⇄ DOT" />
+
+</LinearLayout>

feature-assets/src/main/res/layout/view_bridge_asset_input.xml

@@ -0,0 +1,124 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout">
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/bridgeAssetInputContainer"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        tools:background="@color/input_background">
+
+        <ImageView
+            android:id="@+id/bridgeAssetInputImage"
+            android:layout_width="40dp"
+            android:layout_height="40dp"
+            android:layout_marginStart="12dp"
+            android:layout_marginTop="16dp"
+            android:layout_marginBottom="16dp"
+            android:background="@drawable/bg_token_container"
+            android:scaleType="centerInside"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent"
+            tools:src="@drawable/ic_token_dot_colored" />
+
+        <ImageView
+            android:id="@+id/bridgeAssetInputSubtitleImage"
+            android:layout_width="12dp"
+            android:layout_height="12dp"
+            android:layout_marginEnd="4dp"
+            app:layout_constraintBottom_toBottomOf="@+id/bridgeAssetInputSubtitle"
+            app:layout_constraintStart_toEndOf="@+id/bridgeAssetInputImageBarrier"
+            app:layout_constraintTop_toTopOf="@+id/bridgeAssetInputSubtitle"
+            tools:src="@drawable/ic_pezkuwi_logo" />
+
+        <androidx.constraintlayout.widget.Barrier
+            android:id="@+id/bridgeAssetInputImageBarrier"
+            android:layout_width="0dp"
+            android:layout_height="match_parent"
+            app:barrierDirection="end"
+            app:barrierMargin="12dp"
+            app:constraint_referenced_ids="bridgeAssetInputImage" />
+
+        <TextView
+            android:id="@+id/bridgeAssetInputToken"
+            style="@style/TextAppearance.NovaFoundation.SemiBold.Body"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="12dp"
+            android:includeFontPadding="false"
+            android:textColor="@color/text_primary"
+            app:layout_constraintBottom_toTopOf="@+id/bridgeAssetInputSubtitle"
+            app:layout_constraintStart_toEndOf="@id/bridgeAssetInputImage"
+            app:layout_constraintTop_toTopOf="parent"
+            app:layout_constraintVertical_chainStyle="packed"
+            tools:text="DOT" />
+
+        <TextView
+            android:id="@+id/bridgeAssetInputSubtitle"
+            style="@style/TextAppearance.NovaFoundation.Regular.Footnote"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="8dp"
+            android:layout_marginTop="4dp"
+            android:includeFontPadding="false"
+            android:textColor="@color/text_secondary"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintStart_toEndOf="@+id/bridgeAssetInputSubtitleImage"
+            app:layout_constraintTop_toBottomOf="@+id/bridgeAssetInputToken"
+            tools:text="Polkadot Asset Hub" />
+
+        <ImageView
+            android:id="@+id/bridgeAssetInputChevron"
+            android:layout_width="20dp"
+            android:layout_height="20dp"
+            android:src="@drawable/ic_chevron_right"
+            android:visibility="gone"
+            app:layout_constraintBottom_toBottomOf="@+id/bridgeAssetInputToken"
+            app:layout_constraintStart_toEndOf="@+id/bridgeAssetInputToken"
+            app:layout_constraintTop_toTopOf="@+id/bridgeAssetInputToken"
+            app:tint="@color/icon_primary" />
+
+        <EditText
+            android:id="@+id/bridgeAssetInputField"
+            style="@style/TextAppearance.NovaFoundation.Regular.Title2"
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:layout_marginStart="16dp"
+            android:background="@null"
+            android:gravity="end"
+            android:hint="0"
+            android:inputType="numberDecimal"
+            android:paddingTop="10dp"
+            android:paddingEnd="16dp"
+            android:paddingBottom="10dp"
+            android:saveEnabled="false"
+            android:textColor="@color/text_primary"
+            android:textColorHint="@color/hint_text"
+            android:textCursorDrawable="@null"
+            android:textStyle="bold"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintHorizontal_bias="1.0"
+            app:layout_constraintStart_toEndOf="@+id/bridgeAssetInputChevron"
+            app:layout_constraintTop_toTopOf="parent"
+            tools:text="4.508614" />
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+    <TextView
+        android:id="@+id/bridgeAssetInputError"
+        style="@style/TextAppearance.NovaFoundation.Regular.Caption1"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:textColor="@color/text_negative"
+        android:visibility="gone"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/bridgeAssetInputContainer" />
+
+</merge>

feature-cloud-backup-api/src/main/java/io/novafoundation/nova/feature_cloud_backup_api/domain/model/CloudBackup.kt

@@ -23,7 +23,19 @@ data class CloudBackup(
         val ethereumPublicKey: ByteArray?,
         val name: String,
         val type: Type,
-        val chainAccounts: Set<ChainAccountInfo>
+        val chainAccounts: Set<ChainAccountInfo>,
+        // All below are nullable and defaulted so that Gson deserializing a backup written before that
+        // particular chain family existed - which has no such field in its JSON at all - lands on null here
+        // rather than failing. Solana has no derivation anywhere in this codebase yet (no native support,
+        // unlike Tron/Bitcoin) - its fields are reserved now purely so that adding that support later never
+        // needs another silent-drop-prone trip through every call site that touches this schema, the way
+        // Tron/Bitcoin did when they were bolted onto a schema that only knew about substrate/ethereum.
+        val tronAddress: ByteArray? = null,
+        val tronPublicKey: ByteArray? = null,
+        val solanaAddress: ByteArray? = null,
+        val solanaPublicKey: ByteArray? = null,
+        val bitcoinAddress: ByteArray? = null,
+        val bitcoinPublicKey: ByteArray? = null,
     ) : Identifiable {
 
         override val identifier: String = walletId
@@ -72,7 +84,13 @@ data class CloudBackup(
                 ethereumPublicKey.contentEquals(other.ethereumPublicKey) &&
                 name == other.name &&
                 type == other.type &&
-                chainAccounts == other.chainAccounts
+                chainAccounts == other.chainAccounts &&
+                tronAddress.contentEquals(other.tronAddress) &&
+                tronPublicKey.contentEquals(other.tronPublicKey) &&
+                solanaAddress.contentEquals(other.solanaAddress) &&
+                solanaPublicKey.contentEquals(other.solanaPublicKey) &&
+                bitcoinAddress.contentEquals(other.bitcoinAddress) &&
+                bitcoinPublicKey.contentEquals(other.bitcoinPublicKey)
         }
 
         override fun hashCode(): Int {
@@ -85,6 +103,12 @@ data class CloudBackup(
             result = 31 * result + name.hashCode()
             result = 31 * result + type.hashCode()
             result = 31 * result + chainAccounts.hashCode()
+            result = 31 * result + (tronAddress?.contentHashCode() ?: 0)
+            result = 31 * result + (tronPublicKey?.contentHashCode() ?: 0)
+            result = 31 * result + (solanaAddress?.contentHashCode() ?: 0)
+            result = 31 * result + (solanaPublicKey?.contentHashCode() ?: 0)
+            result = 31 * result + (bitcoinAddress?.contentHashCode() ?: 0)
+            result = 31 * result + (bitcoinPublicKey?.contentHashCode() ?: 0)
             result = 31 * result + identifier.hashCode()
             return result
         }
@@ -100,6 +124,11 @@ data class CloudBackup(
         val substrate: SubstrateSecrets?,
         val ethereum: EthereumSecrets?,
         val chainAccounts: List<ChainAccountSecrets>,
+        // See the matching comment on WalletPublicInfo: tron/bitcoin are fully wired end to end, solana is a
+        // schema-only reservation until native derivation for it exists.
+        val tron: TronSecrets? = null,
+        val solana: SolanaSecrets? = null,
+        val bitcoin: BitcoinSecrets? = null,
     ) : Identifiable {
 
         override val identifier: String = walletId
@@ -118,6 +147,9 @@ data class CloudBackup(
             if (substrate != other.substrate) return false
             if (ethereum != other.ethereum) return false
             if (chainAccounts != other.chainAccounts) return false
+            if (tron != other.tron) return false
+            if (solana != other.solana) return false
+            if (bitcoin != other.bitcoin) return false
             return identifier == other.identifier
         }
 
@@ -127,6 +159,9 @@ data class CloudBackup(
             result = 31 * result + (substrate?.hashCode() ?: 0)
             result = 31 * result + (ethereum?.hashCode() ?: 0)
             result = 31 * result + chainAccounts.hashCode()
+            result = 31 * result + (tron?.hashCode() ?: 0)
+            result = 31 * result + (solana?.hashCode() ?: 0)
+            result = 31 * result + (bitcoin?.hashCode() ?: 0)
             result = 31 * result + identifier.hashCode()
             return result
         }
@@ -201,6 +236,22 @@ data class CloudBackup(
             val derivationPath: String?,
         )
 
+        data class TronSecrets(
+            val keypair: KeyPairSecrets,
+            val derivationPath: String?,
+        )
+
+        // Reserved shape for when native Solana derivation is added - unused until then, see the class-level comment.
+        data class SolanaSecrets(
+            val keypair: KeyPairSecrets,
+            val derivationPath: String?,
+        )
+
+        data class BitcoinSecrets(
+            val keypair: KeyPairSecrets,
+            val derivationPath: String?,
+        )
+
         data class KeyPairSecrets(
             val publicKey: ByteArray,
             val privateKey: ByteArray,
@@ -234,5 +285,5 @@ data class CloudBackup(
 }
 
 fun CloudBackup.WalletPrivateInfo.isCompletelyEmpty(): Boolean {
-    return entropy == null && substrate == null && ethereum == null && chainAccounts.isEmpty()
+    return entropy == null && substrate == null && ethereum == null && tron == null && bitcoin == null && chainAccounts.isEmpty()
 }

feature-cloud-backup-test/src/main/java/io/novafoundation/feature_cloud_backup_test/CloudBackupBuilder.kt

@@ -7,6 +7,7 @@ import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPrivateInfo.EthereumSecrets
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPrivateInfo.KeyPairSecrets
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPrivateInfo.SubstrateSecrets
+import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPrivateInfo.TronSecrets
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPublicInfo
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPublicInfo.ChainAccountInfo
 import io.novafoundation.nova.feature_cloud_backup_api.domain.model.CloudBackup.WalletPublicInfo.ChainAccountInfo.ChainAccountCryptoType
@@ -99,6 +100,7 @@ class WalletPrivateInfoBuilder(
 
     private var substrate: SubstrateSecrets? = null
     private var ethereum: EthereumSecrets? = null
+    private var tron: TronSecrets? = null
 
     private val chainAccounts = mutableListOf<ChainAccountSecrets>()
 
@@ -114,6 +116,10 @@ class WalletPrivateInfoBuilder(
         ethereum = BackupEthereumSecretsBuilder().apply(builder).build()
     }
 
+    fun tron(builder: BackupTronSecretsBuilder.() -> Unit) {
+        tron = BackupTronSecretsBuilder().apply(builder).build()
+    }
+
     fun chainAccount(accountId: AccountId, builder: (BackupChainAccountSecretsBuilder.() -> Unit)? = null) {
         val element = BackupChainAccountSecretsBuilder(accountId).apply { builder?.invoke(this) }.build()
         chainAccounts.add(element)
@@ -126,6 +132,7 @@ class WalletPrivateInfoBuilder(
             substrate = substrate,
             ethereum = ethereum,
             chainAccounts = chainAccounts,
+            tron = tron,
         )
     }
 }
@@ -173,6 +180,25 @@ class BackupEthereumSecretsBuilder {
     }
 }
 
+@CloudBackupBuildDsl
+class BackupTronSecretsBuilder {
+
+    private var _keypair: KeyPairSecrets? = null
+    private var _derivationPath: String? = null
+
+    fun derivationPath(value: String?) {
+        _derivationPath = value
+    }
+
+    fun keypair(keypair: KeyPairSecrets) {
+        _keypair = keypair
+    }
+
+    fun build(): TronSecrets {
+        return TronSecrets(requireNotNull(_keypair), _derivationPath)
+    }
+}
+
 @CloudBackupBuildDsl
 class BackupChainAccountSecretsBuilder(private val accountId: AccountId) {
 
@@ -223,6 +249,8 @@ class WalletPublicInfoBuilder(
     private var _substrateAccountId: ByteArray? = null
     private var _ethereumPublicKey: ByteArray? = null
     private var _ethereumAddress: ByteArray? = null
+    private var _tronPublicKey: ByteArray? = null
+    private var _tronAddress: ByteArray? = null
     private var _name: String = ""
     private var _isSelected: Boolean = false
     private var _type: WalletPublicInfo.Type = WalletPublicInfo.Type.SECRETS
@@ -252,6 +280,14 @@ class WalletPublicInfoBuilder(
         _ethereumAddress = value
     }
 
+    fun tronPublicKey(value: ByteArray?) {
+        _tronPublicKey = value
+    }
+
+    fun tronAddress(value: ByteArray?) {
+        _tronAddress = value
+    }
+
     fun name(value: String) {
         _name = value
     }
@@ -274,7 +310,9 @@ class WalletPublicInfoBuilder(
             ethereumPublicKey = _ethereumPublicKey,
             name = _name,
             type = _type,
-            chainAccounts = chainAccounts.toSet()
+            chainAccounts = chainAccounts.toSet(),
+            tronAddress = _tronAddress,
+            tronPublicKey = _tronPublicKey,
         )
     }
 }

feature-settings-impl/src/main/java/io/novafoundation/nova/feature_settings_impl/domain/NetworkManagementChainInteractor.kt

@@ -9,6 +9,7 @@ import io.novafoundation.nova.runtime.ext.isCustomNetwork
 import io.novafoundation.nova.runtime.ext.isDisabled
 import io.novafoundation.nova.runtime.ext.isEnabled
 import io.novafoundation.nova.runtime.ext.selectedUnformattedWssNodeUrlOrNull
+import io.novafoundation.nova.runtime.ext.httpNodes
 import io.novafoundation.nova.runtime.ext.wssNodes
 import io.novafoundation.nova.runtime.multiNetwork.ChainRegistry
 import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
@@ -132,7 +133,13 @@ class RealNetworkManagementChainInteractor(
     }
 
     private fun nodesHealthState(chain: Chain, coroutineScope: CoroutineScope): Flow<List<NodeHealthState>> {
-        return chain.nodes.wssNodes().map {
+        // wssNodes() alone leaves an HTTPS-only chain (Tron today - no wss endpoint at all) with an empty list
+        // here, which silently renders as "nothing to show" rather than a real health state - fall back to the
+        // http nodes only when there are no wss ones, since a chain that genuinely has wss nodes should still
+        // prefer testing those.
+        val nodesToCheck = chain.nodes.wssNodes().ifEmpty { chain.nodes.httpNodes() }
+
+        return nodesToCheck.map {
             nodeHealthState(chain, it, coroutineScope)
         }.combine()
     }

feature-settings-impl/src/main/java/io/novafoundation/nova/feature_settings_impl/domain/utils/CustomChainFactory.kt

@@ -125,6 +125,7 @@ class CustomChainFactory(
             types = prefilledChain?.types,
             isEthereumBased = isEthereumBased,
             isTronBased = false,
+            isBitcoinBased = false,
             isTestNet = prefilledChain?.isTestNet.orFalse(),
             source = Chain.Source.CUSTOM,
             hasSubstrateRuntime = hasSubstrateRuntime,

feature-settings-impl/src/main/java/io/novafoundation/nova/feature_settings_impl/presentation/networkManagement/networkList/common/NetworkListAdapterItemFactory.kt

@@ -61,6 +61,12 @@ class RealNetworkListAdapterItemFactory(
     private fun getConnectingState(network: NetworkState): ConnectionStateModel? {
         if (network.chain.isDisabled) return null
 
+        // Tron chains never get a ChainConnection/SocketService (TronGrid is a plain REST API, not
+        // WSS JSON-RPC - see ChainRegistry.registerConnection()), so connectionState is always the
+        // Disconnected default here, never Connected. Treat that as "nothing to show" rather than
+        // falling into the generic "Connecting" state below, which would otherwise spin forever.
+        if (network.chain.isTronBased) return null
+
         return when (network.connectionState) {
             is SocketStateMachine.State.Connected -> null
 

feature-wallet-api/src/main/java/io/novafoundation/nova/feature_wallet_api/data/network/blockhain/assets/tranfers/TransactionExecution.kt

@@ -8,4 +8,8 @@ sealed interface TransactionExecution {
     class Ethereum(val ethereumTransactionExecution: EthereumTransactionExecution) : TransactionExecution
 
     class Substrate(val extrinsicExecutionResult: ExtrinsicExecutionResult) : TransactionExecution
+
+    class Bitcoin(val hash: String) : TransactionExecution
+
+    class Tron(val hash: String) : TransactionExecution
 }

feature-wallet-impl/build.gradle

@@ -27,6 +27,17 @@ android {
     }
     namespace 'io.novafoundation.nova.feature_wallet_impl'
 
+    testOptions {
+        unitTests.all {
+            testLogging {
+                events "failed"
+                exceptionFormat "full"
+                showCauses true
+                showStackTraces true
+            }
+        }
+    }
+
     buildFeatures {
         viewBinding true
     }
@@ -71,6 +82,7 @@ dependencies {
 
     testImplementation jUnitDep
     testImplementation mockitoDep
+    testImplementation project(':test-shared')
 
     implementation substrateSdkDep
 

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/BitcoinApi.kt

@@ -0,0 +1,81 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin
+
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.types.Balance
+import kotlinx.coroutines.delay
+import retrofit2.HttpException
+import java.math.BigInteger
+
+/** A single unspent output, as needed to select inputs and build a transaction. */
+data class BitcoinUtxo(
+    val txid: String,
+    val vout: Int,
+    val valueSat: Long,
+    val confirmed: Boolean,
+)
+
+interface BitcoinApi {
+
+    suspend fun fetchNativeBalance(baseUrl: String, address: String): Balance
+
+    suspend fun fetchUtxos(baseUrl: String, address: String): List<BitcoinUtxo>
+
+    /** sat/vB, mempool.space's ~30-minute-confirmation estimate - a balanced default, neither cheapest nor fastest. */
+    suspend fun fetchRecommendedFeeRateSatPerVbyte(baseUrl: String): Long
+
+    /** @param rawTxHex fully signed raw transaction, hex-encoded. @return the broadcast transaction's txid. */
+    suspend fun broadcastTransaction(baseUrl: String, rawTxHex: String): String
+}
+
+class RealBitcoinApi(
+    private val retrofitApi: RetrofitBitcoinApi
+) : BitcoinApi {
+
+    override suspend fun fetchNativeBalance(baseUrl: String, address: String): Balance {
+        val stats = retryOn429 { retrofitApi.getAddress(addressUrl(baseUrl, address)) }.chainStats
+            ?: return BigInteger.ZERO
+
+        val funded = stats.fundedTxoSum ?: 0L
+        val spent = stats.spentTxoSum ?: 0L
+
+        return (funded - spent).toBigInteger().coerceAtLeast(BigInteger.ZERO)
+    }
+
+    override suspend fun fetchUtxos(baseUrl: String, address: String): List<BitcoinUtxo> {
+        val response = retryOn429 { retrofitApi.getUtxos("${baseUrl.trimEnd('/')}/address/$address/utxo") }
+
+        return response.map { utxo ->
+            BitcoinUtxo(
+                txid = utxo.txid,
+                vout = utxo.vout,
+                valueSat = utxo.value,
+                confirmed = utxo.status?.confirmed == true
+            )
+        }
+    }
+
+    override suspend fun fetchRecommendedFeeRateSatPerVbyte(baseUrl: String): Long {
+        val fees = retryOn429 { retrofitApi.getRecommendedFees("${baseUrl.trimEnd('/')}/v1/fees/recommended") }
+
+        return fees.halfHourFee ?: fees.hourFee ?: fees.fastestFee ?: 1L
+    }
+
+    override suspend fun broadcastTransaction(baseUrl: String, rawTxHex: String): String {
+        return retryOn429 { retrofitApi.broadcastTransaction("${baseUrl.trimEnd('/')}/tx", rawTxHex) }.trim()
+    }
+
+    private fun addressUrl(baseUrl: String, address: String): String {
+        return "${baseUrl.trimEnd('/')}/address/$address"
+    }
+
+    private suspend fun <T> retryOn429(maxAttempts: Int = 4, block: suspend () -> T): T {
+        repeat(maxAttempts - 1) { attempt ->
+            try {
+                return block()
+            } catch (e: HttpException) {
+                if (e.code() != 429) throw e
+                delay(1_000L * (attempt + 1))
+            }
+        }
+        return block()
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/RetrofitBitcoinApi.kt

@@ -0,0 +1,30 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin
+
+import io.novafoundation.nova.common.data.network.UserAgent
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.model.BitcoinAddressResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.model.BitcoinFeeEstimateResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.model.BitcoinUtxoResponse
+import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.Headers
+import retrofit2.http.POST
+import retrofit2.http.Url
+
+interface RetrofitBitcoinApi {
+
+    @GET
+    @Headers(UserAgent.NOVA)
+    suspend fun getAddress(@Url url: String): BitcoinAddressResponse
+
+    @GET
+    @Headers(UserAgent.NOVA)
+    suspend fun getUtxos(@Url url: String): List<BitcoinUtxoResponse>
+
+    @GET
+    @Headers(UserAgent.NOVA)
+    suspend fun getRecommendedFees(@Url url: String): BitcoinFeeEstimateResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun broadcastTransaction(@Url url: String, @Body rawTxHex: String): String
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/model/BitcoinAddressResponse.kt

@@ -0,0 +1,22 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.model
+
+import com.google.gson.annotations.SerializedName
+
+/**
+ * Response shape of mempool.space's `GET /address/{address}`.
+ *
+ * `chainStats` reflects only confirmed on-chain activity; `mempoolStats` (unconfirmed) is deliberately not
+ * used for balance - matching the exchange's proven 2-confirmation-required posture for this same API.
+ */
+class BitcoinAddressResponse(
+    @SerializedName("chain_stats")
+    val chainStats: BitcoinAddressStats? = null,
+)
+
+class BitcoinAddressStats(
+    @SerializedName("funded_txo_sum")
+    val fundedTxoSum: Long? = null,
+
+    @SerializedName("spent_txo_sum")
+    val spentTxoSum: Long? = null,
+)

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/model/BitcoinUtxoResponse.kt

@@ -0,0 +1,22 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.model
+
+/** Response shape of mempool.space's `GET /address/{address}/utxo`. */
+class BitcoinUtxoResponse(
+    val txid: String,
+    val vout: Int,
+    val value: Long,
+    val status: BitcoinUtxoStatus? = null,
+)
+
+class BitcoinUtxoStatus(
+    val confirmed: Boolean = false,
+)
+
+/** Response shape of mempool.space's `GET /v1/fees/recommended`, all values in sat/vB. */
+class BitcoinFeeEstimateResponse(
+    val fastestFee: Long? = null,
+    val halfHourFee: Long? = null,
+    val hourFee: Long? = null,
+    val economyFee: Long? = null,
+    val minimumFee: Long? = null,
+)

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/transaction/BitcoinTransactionService.kt

@@ -0,0 +1,41 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.transaction
+
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.TransactionOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import java.math.BigInteger
+
+/**
+ * Mirrors [io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionService]'s
+ * shape (calculateFee/transact/transactAndAwaitExecution over a sending origin), but for Bitcoin. See
+ * `RealBitcoinTransactionService` for the UTXO-model construction/signing details, which differ substantially
+ * from Tron's account-model approach.
+ *
+ * [recipientAddress] is the raw destination address string, not an [io.novasama.substrate_sdk_android.runtime.AccountId] -
+ * unlike every other chain's transfer path, a Bitcoin destination can legitimately be a P2SH/P2PKH address (a
+ * real exchange withdrawal address was confirmed to be P2SH-only, with no way to request native SegWit instead),
+ * which needs its own distinct scriptPubKey shape. Converting to a generic 20-byte AccountId this early would
+ * discard which shape it needs to be - see `BitcoinDestinationAddress.kt`.
+ */
+interface BitcoinTransactionService {
+
+    suspend fun calculateFee(chain: Chain, origin: TransactionOrigin, recipientAddress: String, amountSat: BigInteger): Fee
+
+    suspend fun transact(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipientAddress: String,
+        presetFee: Fee?,
+        amountSat: BigInteger
+    ): Result<ExtrinsicSubmission>
+
+    suspend fun transactAndAwaitExecution(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipientAddress: String,
+        presetFee: Fee?,
+        amountSat: BigInteger
+    ): Result<TransactionExecution>
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/bitcoin/transaction/RealBitcoinTransactionService.kt

@@ -0,0 +1,191 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.transaction
+
+import io.novafoundation.nova.common.utils.BitcoinInput
+import io.novafoundation.nova.common.utils.BitcoinOutput
+import io.novafoundation.nova.common.utils.BitcoinTransaction
+import io.novafoundation.nova.common.utils.DerSignature
+import io.novafoundation.nova.common.utils.decodeBitcoinDestination
+import io.novafoundation.nova.common.utils.toBitcoinAddress
+import io.novafoundation.nova.common.utils.toEcdsaSignatureData
+import io.novafoundation.nova.common.utils.toP2wpkhScriptPubKey
+import io.novafoundation.nova.common.utils.toScriptPubKey
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.TransactionOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.extrinsic.SubmissionOrigin
+import io.novafoundation.nova.feature_account_api.data.model.BitcoinFee
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_account_api.data.signer.CallExecutionType
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
+import io.novafoundation.nova.feature_account_api.data.signer.SubmissionHierarchy
+import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
+import io.novafoundation.nova.feature_account_api.domain.interfaces.requireMetaAccountFor
+import io.novafoundation.nova.feature_account_api.domain.model.requireAccountIdIn
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.BitcoinApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.BitcoinUtxo
+import io.novafoundation.nova.runtime.ext.commissionAsset
+import io.novafoundation.nova.runtime.ext.requireMempoolSpaceBaseUrl
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import io.novasama.substrate_sdk_android.runtime.extrinsic.signer.SignerPayloadRaw
+import java.math.BigInteger
+
+/** mempool.space's own dust threshold for a P2WPKH output - see `RealBitcoinTransactionService`'s doc for how this is used. */
+private const val DUST_LIMIT_SAT = 546L
+
+private const val TX_VERSION = 2
+private const val LOCKTIME = 0
+
+private data class UtxoSelection(
+    val selectedUtxos: List<BitcoinUtxo>,
+    val changeSat: Long,
+    val feeSat: Long,
+)
+
+/**
+ * Builds, signs and broadcasts Bitcoin transactions from this wallet's own native SegWit (P2WPKH) address - the
+ * recipient output, however, can be P2WPKH, P2SH or P2PKH (see `BitcoinDestinationAddress.kt`; a real exchange
+ * withdrawal address was confirmed live to be P2SH-only). UTXO selection and raw construction happen entirely
+ * client-side (no server-assisted "createtransaction" the way TronGrid offers - mempool.space only exposes
+ * UTXOs/fee-rate/broadcast, not transaction construction), using the hand-rolled protocol primitives in
+ * [BitcoinTransaction]/[DerSignature]/`BitcoinAddress.kt` verified against BIP143/BIP173.
+ *
+ * ## UTXO selection
+ * Greedy largest-first over CONFIRMED UTXOs only (unconfirmed outputs are skipped - spending them risks the
+ * whole transaction unraveling if the parent is replaced/dropped), matching the exchange's proven approach.
+ * If the leftover after amount+fee would be below Bitcoin's dust threshold ([DUST_LIMIT_SAT]), no change output
+ * is created and the leftover is folded into the fee instead of producing an uneconomical-to-spend output.
+ *
+ * ## Fee
+ * `feeRate (sat/vB, from mempool.space's ~30-minute estimate) * estimated vsize` (the same
+ * `inputs*68 + outputs*31 + 11` heuristic already proven in production by `pezkuwi-exchange/wallet-service`).
+ *
+ * ## Signing
+ * Each input gets its own BIP143 sighash (unlike Tron/Ethereum's single whole-transaction hash) - computed by
+ * [BitcoinTransaction.bip143Sighash], signed via the same [io.novafoundation.nova.feature_account_api.data.signer.NovaSigner.signRaw]
+ * primitive Tron/Ethereum already use (`skipMessageHashing = true`, since the sighash is already the final
+ * digest to sign), then DER-encoded with low-S normalization via [DerSignature] - Bitcoin's one departure from
+ * Tron/Ethereum's fixed compact r+s+v format. No new signing call path was added.
+ *
+ * ## Broadcast
+ * `POST /tx` with the fully serialized signed transaction, hex-encoded, as a raw text body.
+ */
+class RealBitcoinTransactionService(
+    private val accountRepository: AccountRepository,
+    private val signerProvider: SignerProvider,
+    private val bitcoinApi: BitcoinApi,
+) : BitcoinTransactionService {
+
+    override suspend fun calculateFee(chain: Chain, origin: TransactionOrigin, recipientAddress: String, amountSat: BigInteger): Fee {
+        val submittingMetaAccount = accountRepository.requireMetaAccountFor(origin, chain.id)
+        val ownerAccountId = submittingMetaAccount.requireAccountIdIn(chain)
+        val baseUrl = chain.requireMempoolSpaceBaseUrl()
+
+        val utxos = confirmedUtxos(baseUrl, ownerAccountId)
+        val feeRate = bitcoinApi.fetchRecommendedFeeRateSatPerVbyte(baseUrl)
+        val selection = selectUtxos(utxos, amountSat.toLong().coerceAtLeast(0), feeRate)
+
+        val feeSat = selection?.feeSat ?: 0L
+
+        return BitcoinFee(feeSat.toBigInteger(), SubmissionOrigin.singleOrigin(ownerAccountId), chain.commissionAsset)
+    }
+
+    override suspend fun transact(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipientAddress: String,
+        presetFee: Fee?,
+        amountSat: BigInteger
+    ): Result<ExtrinsicSubmission> = runCatching {
+        val submittingMetaAccount = accountRepository.requireMetaAccountFor(origin, chain.id)
+        val ownerAccountId = submittingMetaAccount.requireAccountIdIn(chain)
+        val ownerPublicKey = requireNotNull(submittingMetaAccount.bitcoinPublicKey) {
+            "No bitcoin public key found for meta account ${submittingMetaAccount.id}"
+        }
+        val baseUrl = chain.requireMempoolSpaceBaseUrl()
+        val amountSatLong = amountSat.toLong()
+        val recipientScriptPubKey = recipientAddress.decodeBitcoinDestination().toScriptPubKey()
+
+        val utxos = confirmedUtxos(baseUrl, ownerAccountId)
+        val feeRate = bitcoinApi.fetchRecommendedFeeRateSatPerVbyte(baseUrl)
+        val selection = selectUtxos(utxos, amountSatLong, feeRate)
+            ?: error("Insufficient confirmed UTXOs to cover amount + fee")
+
+        val inputs = selection.selectedUtxos.map { utxo ->
+            BitcoinInput(txid = utxo.txid.fromHex(), vout = utxo.vout, valueSat = utxo.valueSat)
+        }
+
+        val outputs = buildList {
+            add(BitcoinOutput(valueSat = amountSatLong, scriptPubKey = recipientScriptPubKey))
+            if (selection.changeSat > 0) {
+                add(BitcoinOutput(valueSat = selection.changeSat, scriptPubKey = ownerAccountId.toP2wpkhScriptPubKey()))
+            }
+        }
+
+        val signer = signerProvider.rootSignerFor(submittingMetaAccount)
+
+        val witnesses = inputs.indices.map { index ->
+            val sighash = BitcoinTransaction.bip143Sighash(TX_VERSION, inputs, outputs, index, ownerAccountId, LOCKTIME)
+            val signedRaw = signer.signRaw(SignerPayloadRaw(message = sighash, accountId = ownerAccountId, skipMessageHashing = true))
+            val signature = signedRaw.toEcdsaSignatureData()
+
+            DerSignature.encode(signature.r, signature.s) to ownerPublicKey
+        }
+
+        val signedTxBytes = BitcoinTransaction.serializeSigned(TX_VERSION, inputs, outputs, witnesses, LOCKTIME)
+        val txid = bitcoinApi.broadcastTransaction(baseUrl, signedTxBytes.toHexString(withPrefix = false))
+
+        ExtrinsicSubmission(
+            hash = txid,
+            submissionOrigin = SubmissionOrigin.singleOrigin(ownerAccountId),
+            callExecutionType = CallExecutionType.IMMEDIATE,
+            submissionHierarchy = SubmissionHierarchy(submittingMetaAccount, CallExecutionType.IMMEDIATE)
+        )
+    }
+
+    override suspend fun transactAndAwaitExecution(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipientAddress: String,
+        presetFee: Fee?,
+        amountSat: BigInteger
+    ): Result<TransactionExecution> {
+        // Broadcast acceptance is already a strong signal (same posture as Tron/EVM) - this sits outside the
+        // primary send flow's critical path, which only ever calls transact().
+        return transact(chain, origin, recipientAddress, presetFee, amountSat).map { TransactionExecution.Bitcoin(it.hash) }
+    }
+
+    private suspend fun confirmedUtxos(baseUrl: String, ownerAccountId: AccountId): List<BitcoinUtxo> {
+        val address = ownerAccountId.toBitcoinAddress()
+
+        return bitcoinApi.fetchUtxos(baseUrl, address).filter { it.confirmed }
+    }
+
+    private fun selectUtxos(utxos: List<BitcoinUtxo>, amountSat: Long, feeRateSatPerVbyte: Long): UtxoSelection? {
+        val sorted = utxos.sortedByDescending { it.valueSat }
+        val selected = mutableListOf<BitcoinUtxo>()
+        var total = 0L
+
+        for (utxo in sorted) {
+            selected += utxo
+            total += utxo.valueSat
+
+            val vsizeWithChange = BitcoinTransaction.estimateVsize(selected.size, outputCount = 2)
+            val feeWithChange = feeRateSatPerVbyte * vsizeWithChange
+            if (total < amountSat + feeWithChange) continue
+
+            val changeSat = total - amountSat - feeWithChange
+
+            return if (changeSat >= DUST_LIMIT_SAT) {
+                UtxoSelection(selected.toList(), changeSat = changeSat, feeSat = feeWithChange)
+            } else {
+                // Folding a sub-dust leftover into the fee instead of creating an uneconomical-to-spend output.
+                UtxoSelection(selected.toList(), changeSat = 0, feeSat = total - amountSat)
+            }
+        }
+
+        return null
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/TypeBasedAssetSourceRegistry.kt

@@ -31,6 +31,7 @@ class TypeBasedAssetSourceRegistry(
     private val equilibriumAssetSource: Lazy<AssetSource>,
     private val tronNativeSource: Lazy<AssetSource>,
     private val trc20Source: Lazy<AssetSource>,
+    private val bitcoinNativeSource: Lazy<AssetSource>,
     private val unsupportedBalanceSource: AssetSource,
 
     private val nativeAssetEventDetector: NativeAssetEventDetector,
@@ -49,6 +50,7 @@ class TypeBasedAssetSourceRegistry(
             is Chain.Asset.Type.Equilibrium -> equilibriumAssetSource.get()
             is Chain.Asset.Type.TronNative -> tronNativeSource.get()
             is Chain.Asset.Type.Trc20 -> trc20Source.get()
+            is Chain.Asset.Type.BitcoinNative -> bitcoinNativeSource.get()
             Chain.Asset.Type.Unsupported -> unsupportedBalanceSource
         }
     }
@@ -63,6 +65,7 @@ class TypeBasedAssetSourceRegistry(
             add(equilibriumAssetSource.get())
             add(tronNativeSource.get())
             add(trc20Source.get())
+            add(bitcoinNativeSource.get())
         }
     }
 
@@ -72,6 +75,7 @@ class TypeBasedAssetSourceRegistry(
             Chain.Asset.Type.EvmNative,
             is Chain.Asset.Type.TronNative,
             is Chain.Asset.Type.Trc20,
+            is Chain.Asset.Type.BitcoinNative,
 
             Chain.Asset.Type.Unsupported -> UnsupportedEventDetector()
 

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/bitcoinNative/BitcoinBalancePolling.kt

@@ -0,0 +1,30 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.bitcoinNative
+
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.types.Balance
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+
+private const val BITCOIN_BALANCE_POLLING_INTERVAL_MS = 30_000L
+
+/**
+ * mempool.space is a plain REST API with no push/subscription mechanism, same as TronGrid - see
+ * `TronBalancePolling.pollingBalanceFlow`'s doc for the full rationale this mirrors.
+ */
+internal fun pollingBalanceFlow(
+    intervalMs: Long = BITCOIN_BALANCE_POLLING_INTERVAL_MS,
+    fetch: suspend () -> Balance
+): Flow<Balance> = flow {
+    var lastEmitted: Balance? = null
+
+    while (true) {
+        val latest = fetch()
+
+        if (latest != lastEmitted) {
+            lastEmitted = latest
+            emit(latest)
+        }
+
+        delay(intervalMs)
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/bitcoinNative/BitcoinNativeAssetBalance.kt

@@ -0,0 +1,83 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.bitcoinNative
+
+import io.novafoundation.nova.core.updater.SharedRequestsBuilder
+import io.novafoundation.nova.feature_account_api.domain.model.MetaAccount
+import io.novafoundation.nova.feature_wallet_api.data.cache.AssetCache
+import io.novafoundation.nova.feature_wallet_api.data.cache.updateNonLockableAsset
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.balances.AssetBalance
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.balances.BalanceSyncUpdate
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.balances.model.ChainAssetBalance
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.balances.model.TransferableBalanceUpdatePoint
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.BitcoinApi
+import io.novafoundation.nova.runtime.ext.addressOf
+import io.novafoundation.nova.runtime.ext.requireMempoolSpaceBaseUrl
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.emptyFlow
+import kotlinx.coroutines.flow.map
+import java.math.BigInteger
+
+/**
+ * Native BTC balance on a Bitcoin-based chain. Read-only (Phase 4): fetches via a mempool.space-style REST API
+ * and polls for updates, since that API has no push/subscription mechanism. No transfer/history support here -
+ * see `BitcoinAssetsModule` for how this is paired with `UnsupportedAssetTransfers`/`UnsupportedAssetHistory`.
+ */
+class BitcoinNativeAssetBalance(
+    private val assetCache: AssetCache,
+    private val bitcoinApi: BitcoinApi,
+) : AssetBalance {
+
+    override suspend fun startSyncingBalanceLocks(
+        metaAccount: MetaAccount,
+        chain: Chain,
+        chainAsset: Chain.Asset,
+        accountId: AccountId,
+        subscriptionBuilder: SharedRequestsBuilder
+    ): Flow<*> {
+        // Bitcoin native balance does not support locks
+        return emptyFlow<Nothing>()
+    }
+
+    override fun isSelfSufficient(chainAsset: Chain.Asset): Boolean {
+        return true
+    }
+
+    override suspend fun existentialDeposit(chainAsset: Chain.Asset): BigInteger {
+        // Bitcoin does not have an existential deposit concept (UTXO dust limit is enforced at the transfer level, not here)
+        return BigInteger.ZERO
+    }
+
+    override suspend fun queryAccountBalance(chain: Chain, chainAsset: Chain.Asset, accountId: AccountId): ChainAssetBalance {
+        val balance = bitcoinApi.fetchNativeBalance(chain.requireMempoolSpaceBaseUrl(), chain.addressOf(accountId))
+
+        return ChainAssetBalance.fromFree(chainAsset, balance)
+    }
+
+    override suspend fun subscribeAccountBalanceUpdatePoint(
+        chain: Chain,
+        chainAsset: Chain.Asset,
+        accountId: AccountId,
+    ): Flow<TransferableBalanceUpdatePoint> {
+        // Not on the critical sync path (mirrors TronNativeAssetBalance/EvmNativeAssetBalance) - out of scope for Phase 4.
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun startSyncingBalance(
+        chain: Chain,
+        chainAsset: Chain.Asset,
+        metaAccount: MetaAccount,
+        accountId: AccountId,
+        subscriptionBuilder: SharedRequestsBuilder
+    ): Flow<BalanceSyncUpdate> {
+        val baseUrl = chain.requireMempoolSpaceBaseUrl()
+        val address = chain.addressOf(accountId)
+
+        return pollingBalanceFlow { bitcoinApi.fetchNativeBalance(baseUrl, address) }
+            .map { balance ->
+                assetCache.updateNonLockableAsset(metaAccount.id, chainAsset, balance)
+
+                BalanceSyncUpdate.NoCause
+            }
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/statemine/StatemineAssetBalance.kt

@@ -131,6 +131,10 @@ class StatemineAssetBalance(
         )
     }
 
+    // Deliberately lets setup/subscription failures propagate as exceptions rather than swallowing them into
+    // emptyFlow()/BalanceSyncUpdate.NoCause: the caller, FullSyncPaymentUpdater.syncAsset(), wraps this whole
+    // call in a single retryWhen boundary that exists specifically to catch and retry failures like these. If
+    // we swallow here, that boundary never triggers - the asset silently stops syncing instead of retrying.
     override suspend fun startSyncingBalance(
         chain: Chain,
         chainAsset: Chain.Asset,
@@ -138,40 +142,32 @@ class StatemineAssetBalance(
         accountId: AccountId,
         subscriptionBuilder: SharedRequestsBuilder
     ): Flow<BalanceSyncUpdate> {
-        return runCatching {
+        val runtime = chainRegistry.getRuntime(chain.id)
-            val runtime = chainRegistry.getRuntime(chain.id)
 
-            val statemineType = chainAsset.requireStatemine()
+        val statemineType = chainAsset.requireStatemine()
-            val encodableAssetId = statemineType.prepareIdForEncoding(runtime)
+        val encodableAssetId = statemineType.prepareIdForEncoding(runtime)
 
-            val module = runtime.metadata.statemineModule(statemineType)
+        val module = runtime.metadata.statemineModule(statemineType)
 
-            val assetAccountStorage = module.storage("Account")
+        val assetAccountStorage = module.storage("Account")
-            val assetAccountKey = assetAccountStorage.storageKey(runtime, encodableAssetId, accountId)
+        val assetAccountKey = assetAccountStorage.storageKey(runtime, encodableAssetId, accountId)
 
-            val assetDetailsFlow = statemineAssetsRepository.subscribeAndSyncAssetDetails(chain.id, statemineType, subscriptionBuilder)
+        val assetDetailsFlow = statemineAssetsRepository.subscribeAndSyncAssetDetails(chain.id, statemineType, subscriptionBuilder)
 
-            combine(
+        return combine(
-                subscriptionBuilder.subscribe(assetAccountKey),
+            subscriptionBuilder.subscribe(assetAccountKey),
-                assetDetailsFlow.map { it.status.transfersFrozen }
+            assetDetailsFlow.map { it.status.transfersFrozen }
-            ) { balanceStorageChange, isAssetFrozen ->
+        ) { balanceStorageChange, isAssetFrozen ->
-                val assetAccountDecoded = assetAccountStorage.decodeValue(balanceStorageChange.value, runtime)
+            val assetAccountDecoded = assetAccountStorage.decodeValue(balanceStorageChange.value, runtime)
-                val assetAccount = bindAssetAccountOrEmpty(assetAccountDecoded)
+            val assetAccount = bindAssetAccountOrEmpty(assetAccountDecoded)
 
-                val assetChanged = updateAssetBalance(metaAccount.id, chainAsset, isAssetFrozen, assetAccount)
+            val assetChanged = updateAssetBalance(metaAccount.id, chainAsset, isAssetFrozen, assetAccount)
 
-                if (assetChanged) {
+            if (assetChanged) {
-                    BalanceSyncUpdate.CauseFetchable(balanceStorageChange.block)
+                BalanceSyncUpdate.CauseFetchable(balanceStorageChange.block)
-                } else {
+            } else {
-                    BalanceSyncUpdate.NoCause
+                BalanceSyncUpdate.NoCause
-                }
-            }.catch { error ->
-                Log.e(LOG_TAG, "Balance sync failed for ${chainAsset.symbol} on ${chain.name}: ${error.message}")
-                emit(BalanceSyncUpdate.NoCause)
             }
-        }.getOrElse { error ->
-            Log.e(LOG_TAG, "Failed to start balance sync for ${chainAsset.symbol} on ${chain.name}: ${error.message}")
-            emptyFlow()
         }
     }
 

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/trc20/Trc20AssetBalance.kt

@@ -10,7 +10,6 @@ import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.b
 import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.balances.model.TransferableBalanceUpdatePoint
 import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.tronNative.pollingBalanceFlow
 import io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi
-import io.novafoundation.nova.runtime.ext.addressOf
 import io.novafoundation.nova.runtime.ext.requireTronGridBaseUrl
 import io.novafoundation.nova.runtime.ext.requireTrc20
 import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
@@ -21,9 +20,9 @@ import kotlinx.coroutines.flow.map
 import java.math.BigInteger
 
 /**
- * TRC-20 token balance on a Tron-based chain. Read-only (Phase 1): fetches via TronGrid's REST API (the same
+ * TRC-20 token balance on a Tron-based chain. Read-only (Phase 1): fetches via an on-chain `balanceOf` contract
- * `/v1/accounts/{address}` endpoint used for native TRX - TronGrid returns both in one response) and polls for
+ * call (see [TronGridApi.fetchTrc20Balance] for why this can't reuse the `/v1/accounts` endpoint that native
- * updates. No transfer/history support here - see `TronAssetsModule`.
+ * TRX balance reads from) and polls for updates. No transfer/history support here - see `TronAssetsModule`.
  */
 class Trc20AssetBalance(
     private val assetCache: AssetCache,
@@ -52,9 +51,8 @@ class Trc20AssetBalance(
 
     override suspend fun queryAccountBalance(chain: Chain, chainAsset: Chain.Asset, accountId: AccountId): ChainAssetBalance {
         val contractAddress = chainAsset.requireTrc20().contractAddress
-        val address = chain.addressOf(accountId)
 
-        val balance = tronGridApi.fetchTrc20Balance(chain.requireTronGridBaseUrl(), address, contractAddress)
+        val balance = tronGridApi.fetchTrc20Balance(chain.requireTronGridBaseUrl(), accountId, contractAddress)
 
         return ChainAssetBalance.fromFree(chainAsset, balance)
     }
@@ -77,9 +75,8 @@ class Trc20AssetBalance(
     ): Flow<BalanceSyncUpdate> {
         val contractAddress = chainAsset.requireTrc20().contractAddress
         val baseUrl = chain.requireTronGridBaseUrl()
-        val address = chain.addressOf(accountId)
 
-        return pollingBalanceFlow { tronGridApi.fetchTrc20Balance(baseUrl, address, contractAddress) }
+        return pollingBalanceFlow { tronGridApi.fetchTrc20Balance(baseUrl, accountId, contractAddress) }
             .map { balance ->
                 assetCache.updateNonLockableAsset(metaAccount.id, chainAsset, balance)
 

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/tronNative/TronBalancePolling.kt

@@ -1,17 +1,26 @@
 package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.tronNative
 
+import android.util.Log
 import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.types.Balance
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 
 private const val TRON_BALANCE_POLLING_INTERVAL_MS = 30_000L
+private const val LOG_TAG = "TronBalancePolling"
 
 /**
  * TronGrid is a plain REST API with no push/subscription mechanism (unlike Ethereum nodes, which expose a
  * `newHeads`-style websocket subscription EVM balance sync piggybacks on). So balance updates for Tron-based
  * assets are polled instead of pushed: fetch immediately, then re-fetch on an interval, only emitting when the
  * balance actually changed.
+ *
+ * A failed fetch() must not escape this loop: any uncaught exception here cancels the whole flow permanently
+ * (the collector - FullSyncPaymentUpdater - only logs and gives up, it doesn't resubscribe), which meant a
+ * single transient failure (DNS hiccup, timeout, momentary connectivity loss during app cold start) could
+ * silently and permanently blackhole a Tron asset - no balance write ever happens, so it never even gets a row
+ * in the local DB and disappears from every UI surface with no visible error. Swallow and retry next interval
+ * instead.
  */
 internal fun pollingBalanceFlow(
     intervalMs: Long = TRON_BALANCE_POLLING_INTERVAL_MS,
@@ -20,9 +29,11 @@ internal fun pollingBalanceFlow(
     var lastEmitted: Balance? = null
 
     while (true) {
-        val latest = fetch()
+        val latest = runCatching { fetch() }
+            .onFailure { Log.e(LOG_TAG, "Tron balance fetch failed, will retry in ${intervalMs}ms", it) }
+            .getOrNull()
 
-        if (latest != lastEmitted) {
+        if (latest != null && latest != lastEmitted) {
             lastEmitted = latest
             emit(latest)
         }

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/balances/utility/NativeAssetBalance.kt

@@ -151,6 +151,17 @@ class NativeAssetBalance(
         }
     }
 
+    // Setup/subscription failures are allowed to propagate rather than being swallowed into emptyFlow()/NoCause:
+    // the caller, FullSyncPaymentUpdater.syncAsset(), wraps this whole call in a single retryWhen boundary meant
+    // to catch and retry exactly these failures. Swallowing here would make that retry boundary never trigger.
+    //
+    // NOTE (2026-07-09): a prior attempt switched this to the typed remoteStorage.subscribe { metadata.system
+    // .account... } DSL, on the theory that it would fix HEZ silently never syncing on Pezkuwi Asset Hub (see
+    // git history). That attempt made things categorically worse - all assets across all 3 Pezkuwi chains
+    // stopped syncing, with logs showing what looked like cross-chain key contamination on the shared
+    // connection. Reverted back to the raw subscriptionBuilder.subscribe(key) form here, which is not broken
+    // for any OTHER native asset on any OTHER chain - only Pezkuwi Asset Hub's HEZ specifically. That narrower
+    // bug is still open; do not re-attempt the DSL swap without first understanding why it caused contamination.
     override suspend fun startSyncingBalance(
         chain: Chain,
         chainAsset: Chain.Asset,
@@ -160,13 +171,7 @@ class NativeAssetBalance(
     ): Flow<BalanceSyncUpdate> {
         val runtime = chainRegistry.getRuntime(chain.id)
 
-        val key = try {
+        val key = runtime.metadata.system().storage("Account").storageKey(runtime, accountId)
-            runtime.metadata.system().storage("Account").storageKey(runtime, accountId)
-        } catch (e: Exception) {
-            Log.e(LOG_TAG, "Failed to construct account storage key: ${e.message} in ${chain.name}")
-
-            return emptyFlow()
-        }
 
         return subscriptionBuilder.subscribe(key)
             .map { change ->
@@ -179,10 +184,6 @@ class NativeAssetBalance(
                     BalanceSyncUpdate.NoCause
                 }
             }
-            .catch { error ->
-                Log.e(LOG_TAG, "Balance sync failed for ${chainAsset.symbol} on ${chain.name}: ${error.message}")
-                emit(BalanceSyncUpdate.NoCause)
-            }
     }
 
     private fun bindBalanceHolds(dynamicInstance: Any?): List<BlockchainHold>? {

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/transfers/bitcoinNative/BitcoinNativeAssetTransfers.kt

@@ -0,0 +1,86 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.bitcoinNative
+
+import io.novafoundation.nova.common.validation.ValidationSystem
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.intoOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSourceRegistry
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfers
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.WeightedAssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.amountInPlanks
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.model.TransferParsedFromCall
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.transaction.BitcoinTransactionService
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.checkForFeeChanges
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.positiveAmount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.recipientIsNotSystemAccount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientBalanceInUsedAsset
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientTransferableBalanceToPayOriginFee
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.validAddress
+import io.novafoundation.nova.feature_wallet_impl.domain.validaiton.recipientCanAcceptTransfer
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.runtime.definitions.types.generics.GenericCall
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * Native BTC transfer. No RBF fee-bumping or replace-by-fee UI is implemented here (out of scope for this
+ * send-only phase) - [BitcoinTransactionService] signals RBF (BIP125) on every input regardless, so a stuck
+ * transaction remains bumpable from a compatible wallet even without in-app support.
+ */
+class BitcoinNativeAssetTransfers(
+    private val bitcoinTransactionService: BitcoinTransactionService,
+    private val assetSourceRegistry: AssetSourceRegistry,
+) : AssetTransfers {
+
+    override fun getValidationSystem(coroutineScope: CoroutineScope) = ValidationSystem {
+        validAddress()
+        recipientIsNotSystemAccount()
+
+        positiveAmount()
+
+        sufficientBalanceInUsedAsset()
+        sufficientTransferableBalanceToPayOriginFee()
+
+        recipientCanAcceptTransfer(assetSourceRegistry)
+
+        checkForFeeChanges(assetSourceRegistry, coroutineScope)
+    }
+
+    override suspend fun calculateFee(transfer: AssetTransfer, coroutineScope: CoroutineScope): Fee {
+        return bitcoinTransactionService.calculateFee(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipientAddress = transfer.recipient,
+            amountSat = transfer.amountInPlanks
+        )
+    }
+
+    override suspend fun performTransfer(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<ExtrinsicSubmission> {
+        return bitcoinTransactionService.transact(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipientAddress = transfer.recipient,
+            presetFee = transfer.fee.submissionFee,
+            amountSat = transfer.amountInPlanks
+        )
+    }
+
+    override suspend fun performTransferAndAwaitExecution(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<TransactionExecution> {
+        return bitcoinTransactionService.transactAndAwaitExecution(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipientAddress = transfer.recipient,
+            presetFee = transfer.fee.submissionFee,
+            amountSat = transfer.amountInPlanks
+        )
+    }
+
+    override suspend fun areTransfersEnabled(chainAsset: Chain.Asset): Boolean {
+        return true
+    }
+
+    override suspend fun parseTransfer(call: GenericCall.Instance, chain: Chain): TransferParsedFromCall? {
+        return null
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/transfers/trc20/Trc20AssetTransfers.kt

@@ -0,0 +1,99 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.trc20
+
+import io.novafoundation.nova.common.validation.ValidationSystem
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.intoOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSourceRegistry
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfers
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.WeightedAssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.amountInPlanks
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.model.TransferParsedFromCall
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.checkForFeeChanges
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.positiveAmount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.recipientIsNotSystemAccount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientBalanceInUsedAsset
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientTransferableBalanceToPayOriginFee
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.validAddress
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionIntent
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionService
+import io.novafoundation.nova.feature_wallet_impl.domain.validaiton.recipientCanAcceptTransfer
+import io.novafoundation.nova.runtime.ext.accountIdOrDefault
+import io.novafoundation.nova.runtime.ext.requireTrc20
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.runtime.definitions.types.generics.GenericCall
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * TRC-20 token transfer (e.g. USDT-TRC20). The fee is always denominated in native TRX, never in the TRC-20
+ * token being sent - same pattern as an ERC-20 transfer's fee being paid in ETH, not the ERC-20 token (compare
+ * [io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.evmErc20.EvmErc20AssetTransfers]).
+ * This falls out for free from [TronTransactionService.calculateFee] always returning a [io.novafoundation.nova.feature_account_api.data.model.TronFee]
+ * denominated in `chain.commissionAsset` (native TRX), combined with the fully-generic
+ * [sufficientTransferableBalanceToPayOriginFee] validation checking that commission asset's balance regardless
+ * of which asset is actually being transferred.
+ */
+class Trc20AssetTransfers(
+    private val tronTransactionService: TronTransactionService,
+    private val assetSourceRegistry: AssetSourceRegistry,
+) : AssetTransfers {
+
+    override fun getValidationSystem(coroutineScope: CoroutineScope) = ValidationSystem {
+        validAddress()
+        recipientIsNotSystemAccount()
+
+        positiveAmount()
+
+        sufficientBalanceInUsedAsset()
+        sufficientTransferableBalanceToPayOriginFee()
+
+        recipientCanAcceptTransfer(assetSourceRegistry)
+
+        checkForFeeChanges(assetSourceRegistry, coroutineScope)
+    }
+
+    override suspend fun calculateFee(transfer: AssetTransfer, coroutineScope: CoroutineScope): Fee {
+        return tronTransactionService.calculateFee(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            intent = transfer.intoTrc20Intent()
+        )
+    }
+
+    override suspend fun performTransfer(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<ExtrinsicSubmission> {
+        return tronTransactionService.transact(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            presetFee = transfer.fee.submissionFee,
+            intent = transfer.intoTrc20Intent()
+        )
+    }
+
+    override suspend fun performTransferAndAwaitExecution(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<TransactionExecution> {
+        return tronTransactionService.transactAndAwaitExecution(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            presetFee = transfer.fee.submissionFee,
+            intent = transfer.intoTrc20Intent()
+        )
+    }
+
+    override suspend fun areTransfersEnabled(chainAsset: Chain.Asset): Boolean {
+        return true
+    }
+
+    override suspend fun parseTransfer(call: GenericCall.Instance, chain: Chain): TransferParsedFromCall? {
+        return null
+    }
+
+    private fun AssetTransfer.intoTrc20Intent(): TronTransactionIntent.Trc20Transfer {
+        val trc20 = originChainAsset.requireTrc20()
+
+        return TronTransactionIntent.Trc20Transfer(trc20.contractAddress, amountInPlanks)
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/transfers/tronNative/TronNativeAssetTransfers.kt

@@ -0,0 +1,90 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.tronNative
+
+import io.novafoundation.nova.common.validation.ValidationSystem
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.intoOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSourceRegistry
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.AssetTransfers
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.WeightedAssetTransfer
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.amountInPlanks
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.model.TransferParsedFromCall
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.checkForFeeChanges
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.positiveAmount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.recipientIsNotSystemAccount
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientBalanceInUsedAsset
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.sufficientTransferableBalanceToPayOriginFee
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.validations.validAddress
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionIntent
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionService
+import io.novafoundation.nova.feature_wallet_impl.domain.validaiton.recipientCanAcceptTransfer
+import io.novafoundation.nova.runtime.ext.accountIdOrDefault
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.runtime.definitions.types.generics.GenericCall
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * Native TRX transfer. No Energy/Bandwidth staking or rental is implemented (out of scope for this send-only
+ * phase) - Tron's default protocol behavior (automatically burning TRX when free Bandwidth is insufficient) is
+ * all that's needed; [TronTransactionService] estimates that burn and reports it as [Fee], and the generic
+ * [sufficientTransferableBalanceToPayOriginFee] validation (same one EVM native/ERC-20 transfers already reuse)
+ * blocks the send if the TRX balance can't cover it.
+ */
+class TronNativeAssetTransfers(
+    private val tronTransactionService: TronTransactionService,
+    private val assetSourceRegistry: AssetSourceRegistry,
+) : AssetTransfers {
+
+    override fun getValidationSystem(coroutineScope: CoroutineScope) = ValidationSystem {
+        validAddress()
+        recipientIsNotSystemAccount()
+
+        positiveAmount()
+
+        sufficientBalanceInUsedAsset()
+        sufficientTransferableBalanceToPayOriginFee()
+
+        recipientCanAcceptTransfer(assetSourceRegistry)
+
+        checkForFeeChanges(assetSourceRegistry, coroutineScope)
+    }
+
+    override suspend fun calculateFee(transfer: AssetTransfer, coroutineScope: CoroutineScope): Fee {
+        return tronTransactionService.calculateFee(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            intent = TronTransactionIntent.Native(transfer.amountInPlanks)
+        )
+    }
+
+    override suspend fun performTransfer(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<ExtrinsicSubmission> {
+        return tronTransactionService.transact(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            presetFee = transfer.fee.submissionFee,
+            intent = TronTransactionIntent.Native(transfer.amountInPlanks)
+        )
+    }
+
+    override suspend fun performTransferAndAwaitExecution(transfer: WeightedAssetTransfer, coroutineScope: CoroutineScope): Result<TransactionExecution> {
+        return tronTransactionService.transactAndAwaitExecution(
+            chain = transfer.originChain,
+            origin = transfer.sender.intoOrigin(),
+            recipient = transfer.originChain.accountIdOrDefault(transfer.recipient),
+            presetFee = transfer.fee.submissionFee,
+            intent = TronTransactionIntent.Native(transfer.amountInPlanks)
+        )
+    }
+
+    override suspend fun areTransfersEnabled(chainAsset: Chain.Asset): Boolean {
+        return true
+    }
+
+    override suspend fun parseTransfer(call: GenericCall.Instance, chain: Chain): TransferParsedFromCall? {
+        return null
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/blockchain/assets/transfers/validations/Common.kt

@@ -121,6 +121,7 @@ private fun Chain.Asset.existentialDepositError(amount: BigDecimal): WillRemoveA
     is Type.Statemine -> WillRemoveAccount.WillTransferDust(amount)
     is Type.EvmErc20, is Type.EvmNative -> WillRemoveAccount.WillBurnDust
     is Type.Trc20, Type.TronNative -> WillRemoveAccount.WillBurnDust
+    Type.BitcoinNative -> WillRemoveAccount.WillBurnDust
     is Type.Equilibrium -> WillRemoveAccount.WillBurnDust
     Type.Unsupported -> throw IllegalArgumentException("Unsupported")
 }

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/RetrofitTronGridApi.kt

@@ -1,14 +1,56 @@
 package io.novafoundation.nova.feature_wallet_impl.data.network.tron
 
 import io.novafoundation.nova.common.data.network.UserAgent
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAccountResourceResponse
 import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAccountResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAddressRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronBroadcastRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronBroadcastResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronChainParametersResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronCreateTransactionRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronTriggerContractRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronTriggerContractResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronUnsignedTransactionResponse
+import io.novafoundation.nova.runtime.BuildConfig
+import retrofit2.http.Body
 import retrofit2.http.GET
 import retrofit2.http.Headers
+import retrofit2.http.POST
 import retrofit2.http.Url
 
+// TronGrid's anonymous rate limit is aggressive enough to surface under normal, human-paced app usage (see
+// RealTronGridApi.retryOn429's doc comment) - a free API key from trongrid.io raises it substantially. Sent on
+// every request rather than only when a 429 is hit, since the point is to avoid needing the retry in the first
+// place, not just to have a fallback.
+private const val TRON_API_KEY_HEADER = "TRON-PRO-API-KEY: " + BuildConfig.TRONGRID_API_KEY
+
 interface RetrofitTronGridApi {
 
     @GET
-    @Headers(UserAgent.NOVA)
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
     suspend fun getAccount(@Url url: String): TronAccountResponse
+
+    @POST
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun createTransaction(@Url url: String, @Body body: TronCreateTransactionRequest): TronUnsignedTransactionResponse
+
+    @POST
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun triggerConstantContract(@Url url: String, @Body body: TronTriggerContractRequest): TronTriggerContractResponse
+
+    @POST
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun triggerSmartContract(@Url url: String, @Body body: TronTriggerContractRequest): TronTriggerContractResponse
+
+    @POST
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun broadcastTransaction(@Url url: String, @Body body: TronBroadcastRequest): TronBroadcastResponse
+
+    @GET
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun getChainParameters(@Url url: String): TronChainParametersResponse
+
+    @POST
+    @Headers(UserAgent.NOVA, TRON_API_KEY_HEADER)
+    suspend fun getAccountResource(@Url url: String, @Body body: TronAddressRequest): TronAccountResourceResponse
 }

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/TronGridApi.kt

@@ -1,39 +1,263 @@
 package io.novafoundation.nova.feature_wallet_impl.data.network.tron
 
+import io.novafoundation.nova.common.utils.toTronHexAddress
+import io.novafoundation.nova.common.utils.tronAddressToHexAddress
 import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.types.Balance
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAccountResourceResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAddressRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronBroadcastRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronBroadcastResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronCreateTransactionRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronTriggerContractRequest
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronTriggerContractResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronUnsignedTransactionResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.Trc20TransferAbi
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import kotlinx.coroutines.delay
+import retrofit2.HttpException
 import java.math.BigInteger
 
+/**
+ * Thrown whenever TronGrid reports a failure via an HTTP-200 body (rather than an HTTP error status), which is
+ * how most `/wallet/` endpoints signal validation/execution failures, e.g.
+ * `{"Error": "... no OwnerAccount."}` from `createtransaction`, or
+ * `{"code": "CONTRACT_VALIDATE_ERROR", "message": "<hex>"}` from `broadcasttransaction`.
+ */
+class TronApiException(message: String) : Exception(message)
+
 interface TronGridApi {
 
     suspend fun fetchNativeBalance(baseUrl: String, address: String): Balance
 
-    suspend fun fetchTrc20Balance(baseUrl: String, address: String, contractAddress: String): Balance
+    /**
+     * Reads via an on-chain `balanceOf(address)` call (`triggerconstantcontract`), NOT `/v1/accounts` - a
+     * TRC-20 balance lives in the token contract's own storage, not in the holder's Account object, so an
+     * address that has only ever received TRC-20 tokens (never native TRX, never otherwise "activated") has no
+     * Account object at all and `/v1/accounts` returns empty for it regardless of its real token balance.
+     * Confirmed live: a wallet holding exactly 5 USDT-TRC20 and zero TRX/activation history returned `data: []`
+     * from `/v1/accounts` while `balanceOf` correctly returned 5000000.
+     */
+    suspend fun fetchTrc20Balance(baseUrl: String, holderAccountId: AccountId, contractAddress: String): Balance
+
+    /**
+     * Builds an unsigned native TRX transfer via `POST /wallet/createtransaction`.
+     * [ownerHexAddress]/[toHexAddress] must be in hex form (`41`-prefixed), matching `visible: false`.
+     *
+     * Note: TronGrid refuses to build this for an owner account that has never been activated on-chain
+     * (confirmed live: returns `{"Error": "... no OwnerAccount."}`) - unlike [triggerSmartContract], which
+     * happily builds a transaction for an unfunded/unactivated owner.
+     */
+    suspend fun createNativeTransfer(baseUrl: String, ownerHexAddress: String, toHexAddress: String, amountSun: BigInteger): TronUnsignedTransactionResponse
+
+    /**
+     * Read-only dry run via `POST /wallet/triggerconstantcontract` - does not require the owner account to hold
+     * any TRX and does not touch chain state. Used to estimate the `energy_used` an actual TRC-20 call would
+     * cost (see [TronTriggerContractResponse.energyUsed]).
+     */
+    suspend fun triggerConstantContract(
+        baseUrl: String,
+        ownerHexAddress: String,
+        contractHexAddress: String,
+        functionSelector: String,
+        parameterHex: String
+    ): TronTriggerContractResponse
+
+    /**
+     * Builds an unsigned TRC-20 contract call via `POST /wallet/triggersmartcontract`. Unlike
+     * [createNativeTransfer], this works even for an owner account that has never been activated on-chain
+     * (confirmed live).
+     */
+    suspend fun triggerSmartContract(
+        baseUrl: String,
+        ownerHexAddress: String,
+        contractHexAddress: String,
+        functionSelector: String,
+        parameterHex: String,
+        feeLimitSun: BigInteger
+    ): TronTriggerContractResponse
+
+    /**
+     * Signs-and-submits via `POST /wallet/broadcasttransaction`. The full [unsigned] transaction (including its
+     * `raw_data` object, not just `raw_data_hex`) must be echoed back verbatim alongside the signature - sending
+     * only `raw_data_hex` + `signature` was confirmed live to fail with a deserialization error on TronGrid's side.
+     *
+     * @return the transaction hash (`txID`) on success.
+     * @throws TronApiException if TronGrid rejects the broadcast (invalid signature, insufficient balance, etc.)
+     */
+    suspend fun broadcastTransaction(baseUrl: String, unsigned: TronUnsignedTransactionResponse, signatureHex: String): String
+
+    /** `key -> value` map from `GET /wallet/getchainparameters`, e.g. `getEnergyFee` (sun/energy), `getTransactionFee` (sun/byte). */
+    suspend fun getChainParameters(baseUrl: String): Map<String, Long>
+
+    suspend fun getAccountResource(baseUrl: String, addressHex: String): TronAccountResourceResponse
 }
 
 class RealTronGridApi(
     private val retrofitApi: RetrofitTronGridApi
 ) : TronGridApi {
 
+    // TronGrid's public (no API key) endpoint rate-limits aggressively - confirmed live to return a bare HTTP
+    // 429 under normal, human-paced usage (not just load testing) once a handful of requests land in a short
+    // window. Without this, a 429 on any call in the send flow (fee estimation re-runs on every keystroke,
+    // broadcast, etc.) surfaced straight to the user as a raw error dialog, and the only way through was to
+    // keep tapping Confirm until a request happened to land outside the rate-limit window. Retrying here means
+    // every TronGrid call gets this transparently, not just the ones a caller remembered to wrap.
+    private suspend fun <T> retryOn429(maxAttempts: Int = 4, block: suspend () -> T): T {
+        repeat(maxAttempts - 1) { attempt ->
+            try {
+                return block()
+            } catch (e: HttpException) {
+                if (e.code() != 429) throw e
+                delay(1_000L * (attempt + 1))
+            }
+        }
+        return block()
+    }
+
     override suspend fun fetchNativeBalance(baseUrl: String, address: String): Balance {
         val accountData = fetchAccountData(baseUrl, address) ?: return BigInteger.ZERO
 
         return accountData.balance?.toBigInteger() ?: BigInteger.ZERO
     }
 
-    override suspend fun fetchTrc20Balance(baseUrl: String, address: String, contractAddress: String): Balance {
+    override suspend fun fetchTrc20Balance(baseUrl: String, holderAccountId: AccountId, contractAddress: String): Balance {
-        val accountData = fetchAccountData(baseUrl, address) ?: return BigInteger.ZERO
+        val response = triggerConstantContract(
+            baseUrl = baseUrl,
+            ownerHexAddress = holderAccountId.toTronHexAddress(),
+            contractHexAddress = contractAddress.tronAddressToHexAddress(),
+            functionSelector = Trc20TransferAbi.BALANCE_OF_FUNCTION_SELECTOR,
+            parameterHex = Trc20TransferAbi.encodeBalanceOfParameters(holderAccountId)
+        )
 
-        val rawBalance = accountData.trc20.orEmpty()
+        val resultHex = response.constantResult?.firstOrNull() ?: return BigInteger.ZERO
-            .firstNotNullOfOrNull { entry -> entry[contractAddress] }
 
-        return rawBalance?.toBigIntegerOrNull() ?: BigInteger.ZERO
+        return runCatching { BigInteger(resultHex, 16) }.getOrDefault(BigInteger.ZERO)
     }
 
-    private suspend fun fetchAccountData(baseUrl: String, address: String) = retrofitApi.getAccount(
+    override suspend fun createNativeTransfer(
-        url = accountUrl(baseUrl, address)
+        baseUrl: String,
-    ).data?.firstOrNull()
+        ownerHexAddress: String,
+        toHexAddress: String,
+        amountSun: BigInteger
+    ): TronUnsignedTransactionResponse {
+        val request = TronCreateTransactionRequest(
+            ownerAddress = ownerHexAddress,
+            toAddress = toHexAddress,
+            amount = amountSun.toLongExactOrThrow("amount")
+        )
+
+        val response = retryOn429 { retrofitApi.createTransaction(walletUrl(baseUrl, "createtransaction"), request) }
+
+        return response.requireConstructed()
+    }
+
+    override suspend fun triggerConstantContract(
+        baseUrl: String,
+        ownerHexAddress: String,
+        contractHexAddress: String,
+        functionSelector: String,
+        parameterHex: String
+    ): TronTriggerContractResponse {
+        val request = TronTriggerContractRequest(
+            ownerAddress = ownerHexAddress,
+            contractAddress = contractHexAddress,
+            functionSelector = functionSelector,
+            parameter = parameterHex
+        )
+
+        return retryOn429 { retrofitApi.triggerConstantContract(walletUrl(baseUrl, "triggerconstantcontract"), request) }
+    }
+
+    override suspend fun triggerSmartContract(
+        baseUrl: String,
+        ownerHexAddress: String,
+        contractHexAddress: String,
+        functionSelector: String,
+        parameterHex: String,
+        feeLimitSun: BigInteger
+    ): TronTriggerContractResponse {
+        val request = TronTriggerContractRequest(
+            ownerAddress = ownerHexAddress,
+            contractAddress = contractHexAddress,
+            functionSelector = functionSelector,
+            parameter = parameterHex,
+            feeLimit = feeLimitSun.toLongExactOrThrow("feeLimit")
+        )
+
+        val response = retryOn429 { retrofitApi.triggerSmartContract(walletUrl(baseUrl, "triggersmartcontract"), request) }
+
+        if (response.result?.result != true) {
+            throw TronApiException(response.result?.message ?: response.result?.code ?: "triggersmartcontract failed without a message")
+        }
+
+        // Only validate that a transaction was actually returned - callers read [TronTriggerContractResponse.transaction] themselves.
+        response.transaction?.requireConstructed()
+
+        return response
+    }
+
+    override suspend fun broadcastTransaction(baseUrl: String, unsigned: TronUnsignedTransactionResponse, signatureHex: String): String {
+        val txId = requireNotNull(unsigned.txID) { "Cannot broadcast a transaction without a txID" }
+
+        val request = TronBroadcastRequest(
+            visible = unsigned.visible ?: false,
+            txID = txId,
+            rawData = requireNotNull(unsigned.rawData) { "Cannot broadcast a transaction without raw_data" },
+            rawDataHex = requireNotNull(unsigned.rawDataHex) { "Cannot broadcast a transaction without raw_data_hex" },
+            signature = listOf(signatureHex)
+        )
+
+        // Safe to retry on 429 specifically: a 429 means TronGrid rejected the request before processing it
+        // (rate limit), not that the transaction may have already been broadcast - unlike a timeout, it can't
+        // cause a double-send.
+        val response = retryOn429 { retrofitApi.broadcastTransaction(walletUrl(baseUrl, "broadcasttransaction"), request) }
+
+        if (response.result != true) {
+            throw TronApiException(response.decodeErrorMessage())
+        }
+
+        return response.txid ?: txId
+    }
+
+    override suspend fun getChainParameters(baseUrl: String): Map<String, Long> {
+        return retryOn429 { retrofitApi.getChainParameters(walletUrl(baseUrl, "getchainparameters")) }
+            .chainParameter
+            .associate { it.key to it.value }
+    }
+
+    override suspend fun getAccountResource(baseUrl: String, addressHex: String): TronAccountResourceResponse {
+        return retryOn429 { retrofitApi.getAccountResource(walletUrl(baseUrl, "getaccountresource"), TronAddressRequest(address = addressHex)) }
+    }
+
+    private suspend fun fetchAccountData(baseUrl: String, address: String) = retryOn429 {
+        retrofitApi.getAccount(url = accountUrl(baseUrl, address))
+    }.data?.firstOrNull()
 
     private fun accountUrl(baseUrl: String, address: String): String {
         return "${baseUrl.trimEnd('/')}/v1/accounts/$address"
     }
+
+    private fun walletUrl(baseUrl: String, method: String): String {
+        return "${baseUrl.trimEnd('/')}/wallet/$method"
+    }
+
+    private fun TronUnsignedTransactionResponse.requireConstructed(): TronUnsignedTransactionResponse {
+        if (error != null) throw TronApiException(error)
+        requireNotNull(rawDataHex) { "TronGrid returned no raw_data_hex and no Error" }
+        requireNotNull(txID) { "TronGrid returned no txID and no Error" }
+
+        return this
+    }
+
+    private fun TronBroadcastResponse.decodeErrorMessage(): String {
+        val decodedMessage = message?.let { hex -> runCatching { hex.fromHex().decodeToString() }.getOrNull() }
+
+        return decodedMessage ?: code ?: "broadcasttransaction failed without a message"
+    }
+
+    private fun BigInteger.toLongExactOrThrow(fieldName: String): Long {
+        return runCatching { longValueExact() }
+            .getOrElse { throw IllegalArgumentException("$fieldName overflows Long: $this") }
+    }
 }

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/model/TronTransactionModels.kt

@@ -0,0 +1,116 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.model
+
+import com.google.gson.JsonObject
+import com.google.gson.annotations.SerializedName
+
+/**
+ * Request/response shapes for TronGrid's transaction-construction/broadcast endpoints (`/wallet/`).
+ *
+ * All requests are sent with `"visible": false`, i.e. addresses are hex-encoded (`41` prefix byte ++ 20-byte
+ * accountId, see `toTronHexAddress`) rather than Base58Check. Every shape below was confirmed against
+ * TronGrid's Shasta testnet (`https://api.shasta.trongrid.io`) with live HTTP calls - see the Phase 2
+ * implementation notes for the exact request/response pairs that were captured.
+ */
+
+class TronCreateTransactionRequest(
+    @SerializedName("owner_address") val ownerAddress: String,
+    @SerializedName("to_address") val toAddress: String,
+    val amount: Long,
+    val visible: Boolean = false,
+)
+
+class TronTriggerContractRequest(
+    @SerializedName("owner_address") val ownerAddress: String,
+    @SerializedName("contract_address") val contractAddress: String,
+    @SerializedName("function_selector") val functionSelector: String,
+    val parameter: String,
+    @SerializedName("fee_limit") val feeLimit: Long? = null,
+    @SerializedName("call_value") val callValue: Long = 0,
+    val visible: Boolean = false,
+)
+
+class TronAddressRequest(
+    val address: String,
+    val visible: Boolean = false,
+)
+
+/**
+ * Shape of the unsigned transaction returned by both `/wallet/createtransaction` (flat, at the top level) and
+ * `/wallet/triggersmartcontract`/`/wallet/triggerconstantcontract` (nested under a `transaction` key - see
+ * [TronTriggerContractResponse]).
+ *
+ * `rawData` is kept as an opaque [JsonObject] rather than being modeled field-by-field: its contents differ
+ * between contract types (`TransferContract` vs `TriggerSmartContract`) and it is never interpreted by this
+ * client - it is only ever echoed back verbatim into the broadcast request alongside the signature. The
+ * cryptographically-authoritative value is [rawDataHex] (`txID == sha256(rawDataHex bytes)`, confirmed live).
+ *
+ * `error` is populated (HTTP 200, not an HTTP error) when construction fails, e.g. an unactivated owner account
+ * trying to build a native TRX transfer returns `{"Error": "... no OwnerAccount."}`.
+ */
+class TronUnsignedTransactionResponse(
+    val visible: Boolean? = null,
+    val txID: String? = null,
+    @SerializedName("raw_data") val rawData: JsonObject? = null,
+    @SerializedName("raw_data_hex") val rawDataHex: String? = null,
+    @SerializedName("Error") val error: String? = null,
+)
+
+class TronContractCallResult(
+    val result: Boolean = false,
+    val code: String? = null,
+    val message: String? = null,
+)
+
+/**
+ * Response of both `/wallet/triggerconstantcontract` (read-only dry run, used for TRC20 fee/energy estimation)
+ * and `/wallet/triggersmartcontract` (real construction, used for the actual TRC20 transfer).
+ */
+class TronTriggerContractResponse(
+    val result: TronContractCallResult? = null,
+    @SerializedName("energy_used") val energyUsed: Long? = null,
+    @SerializedName("constant_result") val constantResult: List<String>? = null,
+    val transaction: TronUnsignedTransactionResponse? = null,
+)
+
+class TronBroadcastRequest(
+    val visible: Boolean,
+    val txID: String,
+    @SerializedName("raw_data") val rawData: JsonObject,
+    @SerializedName("raw_data_hex") val rawDataHex: String,
+    val signature: List<String>,
+)
+
+/**
+ * On success: `{"result": true, "txid": "..."}`.
+ * On failure: `{"code": "CONTRACT_VALIDATE_ERROR", "txid": "...", "message": "<hex-encoded ascii>"}` - confirmed
+ * live by broadcasting a validly-signed but unfunded-account transaction, e.g.
+ * `message` hex-decodes to `"Contract validate error : account [...] does not exist"`.
+ */
+class TronBroadcastResponse(
+    val result: Boolean? = null,
+    val txid: String? = null,
+    val code: String? = null,
+    val message: String? = null,
+)
+
+class TronChainParameter(
+    val key: String,
+    val value: Long = 0,
+)
+
+class TronChainParametersResponse(
+    @SerializedName("chainParameter") val chainParameter: List<TronChainParameter> = emptyList(),
+)
+
+/**
+ * Subset of `/wallet/getaccountresource` fields relevant to fee estimation. Fields are omitted by TronGrid
+ * (rather than sent as `0`) when their value is zero - confirmed live - hence all default to `0`.
+ */
+class TronAccountResourceResponse(
+    val freeNetLimit: Long = 0,
+    val freeNetUsed: Long = 0,
+    @SerializedName("NetLimit") val netLimit: Long = 0,
+    @SerializedName("NetUsed") val netUsed: Long = 0,
+    @SerializedName("EnergyLimit") val energyLimit: Long = 0,
+    @SerializedName("EnergyUsed") val energyUsed: Long = 0,
+)

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/transaction/RealTronTransactionService.kt

@@ -0,0 +1,269 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction
+
+import io.novafoundation.nova.common.utils.castOrNull
+import io.novafoundation.nova.common.utils.sha256
+import io.novafoundation.nova.common.utils.toEcdsaSignatureData
+import io.novafoundation.nova.common.utils.toTronHexAddress
+import io.novafoundation.nova.common.utils.tronAddressToHexAddress
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.TransactionOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.extrinsic.SubmissionOrigin
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_account_api.data.model.TronFee
+import io.novafoundation.nova.feature_account_api.data.signer.CallExecutionType
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
+import io.novafoundation.nova.feature_account_api.data.signer.SubmissionHierarchy
+import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
+import io.novafoundation.nova.feature_account_api.domain.interfaces.requireMetaAccountFor
+import io.novafoundation.nova.feature_account_api.domain.model.MetaAccount
+import io.novafoundation.nova.feature_account_api.domain.model.requireAccountIdIn
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAccountResourceResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronUnsignedTransactionResponse
+import io.novafoundation.nova.runtime.ext.commissionAsset
+import io.novafoundation.nova.runtime.ext.requireTronGridBaseUrl
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import io.novasama.substrate_sdk_android.runtime.extrinsic.signer.SignerPayloadRaw
+import java.math.BigInteger
+
+private const val ENERGY_FEE_PARAM_KEY = "getEnergyFee"
+private const val TRANSACTION_FEE_PARAM_KEY = "getTransactionFee"
+
+// Fallbacks only used if a live `getchainparameters` call fails or is missing the expected key - both values are
+// what was observed live on Shasta testnet at implementation time, which also match Tron's long-standing mainnet
+// defaults; the primary path always fetches live values.
+private val FALLBACK_ENERGY_FEE_SUN = BigInteger.valueOf(420)
+private val FALLBACK_BANDWIDTH_FEE_SUN = BigInteger.valueOf(1000)
+
+// Used only if a triggerconstantcontract dry run fails outright (e.g. transient network error) and returns no
+// energy_used at all - a conservative (intentionally high) stand-in for a simple TRC-20 transfer, which in
+// practice costs on the order of 15-30k energy. Mirrors EvmErc20AssetTransfers' ERC_20_UPPER_GAS_LIMIT fallback.
+private val FALLBACK_TRC20_ENERGY_UNITS = 65_000L
+private val FALLBACK_TRC20_TX_SIZE_BYTES = 350L
+
+// fee_limit sent with triggersmartcontract: Tron only ever burns what a call actually uses (up to this cap), so
+// setting this generously above our own estimate does not cost the user more - it only avoids an OUT_OF_ENERGY
+// failure if our estimate undershoots. Bounded above as a sanity guard against a runaway estimate.
+private val MIN_FEE_LIMIT_SUN = BigInteger.valueOf(15_000_000) // 15 TRX
+private val MAX_FEE_LIMIT_SUN = BigInteger.valueOf(100_000_000) // 100 TRX
+
+private val EMPTY_RESOURCE = TronAccountResourceResponse()
+
+/**
+ * Builds, signs and broadcasts Tron transactions (native TRX and TRC-20) using TronGrid's own REST endpoints for
+ * construction/broadcast, and this app's existing ECDSA signing primitive for signing - no Tron protobuf
+ * (`Transaction`/`TransferContract`/`TriggerSmartContract`) encoding and no new crypto library were added.
+ *
+ * ## Construction
+ * - Native TRX: `POST /wallet/createtransaction` with `{owner_address, to_address, amount}` (all hex-encoded,
+ *   `visible: false`). Requires the owner account to already be activated on-chain (confirmed live: an
+ *   unactivated owner gets `{"Error": "... no OwnerAccount."}`) - in practice this is never hit here, since a
+ *   user can only reach the send flow with a positive TRX balance to send from, which itself implies the account
+ *   was already activated by an earlier incoming transfer.
+ * - TRC-20: `POST /wallet/triggersmartcontract` with the ABI-encoded `transfer(address,uint256)` call (see
+ *   [Trc20TransferAbi]). Unlike `createtransaction`, this was confirmed live to work even for a
+ *   never-activated owner account.
+ *
+ * ## Signing
+ * Tron's signature is `ECDSA_sign(privateKey, sha256(raw_data))` over secp256k1 - the same curve/primitive this
+ * app already uses for Ethereum. [io.novafoundation.nova.feature_account_api.data.signer.NovaSigner.signRaw]
+ * (backed by `substrate_sdk_android`'s `Signer.sign(MultiChainEncryption.Ethereum, message, keypair, skipHashing)`
+ * -> `web3j`'s `Sign.signMessage(hash, keyPair, needToHash = false)`) already supports signing a pre-computed
+ * hash directly via `SignerPayloadRaw.skipMessageHashing = true` - this is exactly the primitive Ethereum-style
+ * raw-hash signing needs, and it is reused as-is here. No new cryptographic code or library was added; only the
+ * hash fed into it differs from the EVM path (`sha256(raw_data)` here vs. an EIP-155 RLP-based digest there).
+ *
+ * `web3j`'s `Sign.signMessage` always left-pads `r`/`s` to exactly 32 bytes and encodes `v` as `27/28` (confirmed
+ * by reading `web3j`'s `Sign.java` source) - which is byte-for-byte the same `r(32) + s(32) + v(1)` = 65-byte
+ * compact signature format Tron expects (confirmed against `tronweb`'s own `ECKeySign` implementation, and
+ * independently confirmed live against Shasta testnet - see the Phase 2 implementation notes).
+ *
+ * ## Broadcast
+ * `POST /wallet/broadcasttransaction` with the full unsigned transaction object (not just `raw_data_hex`) plus
+ * `signature: [<65-byte hex signature>]`.
+ */
+class RealTronTransactionService(
+    private val accountRepository: AccountRepository,
+    private val signerProvider: SignerProvider,
+    private val tronGridApi: TronGridApi,
+) : TronTransactionService {
+
+    override suspend fun calculateFee(chain: Chain, origin: TransactionOrigin, recipient: AccountId, intent: TronTransactionIntent): Fee {
+        val submittingMetaAccount = accountRepository.requireMetaAccountFor(origin, chain.id)
+        val ownerAccountId = submittingMetaAccount.requireAccountIdIn(chain)
+        val baseUrl = chain.requireTronGridBaseUrl()
+        val ownerHex = ownerAccountId.toTronHexAddress()
+
+        val feeSun = when (intent) {
+            is TronTransactionIntent.Native -> estimateNativeFee(baseUrl, ownerHex, recipient, intent.amountSun)
+            is TronTransactionIntent.Trc20Transfer -> estimateTrc20FeeFromContractHex(
+                baseUrl,
+                ownerHex,
+                recipient,
+                intent.contractAddress.tronAddressToHexAddress(),
+                intent.amountSun
+            )
+        }
+
+        return TronFee(feeSun, SubmissionOrigin.singleOrigin(ownerAccountId), chain.commissionAsset)
+    }
+
+    override suspend fun transact(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipient: AccountId,
+        presetFee: Fee?,
+        intent: TronTransactionIntent
+    ): Result<ExtrinsicSubmission> = runCatching {
+        val submittingMetaAccount = accountRepository.requireMetaAccountFor(origin, chain.id)
+        val ownerAccountId = submittingMetaAccount.requireAccountIdIn(chain)
+        val baseUrl = chain.requireTronGridBaseUrl()
+        val ownerHex = ownerAccountId.toTronHexAddress()
+        val recipientHex = recipient.toTronHexAddress()
+
+        val unsigned = when (intent) {
+            is TronTransactionIntent.Native -> tronGridApi.createNativeTransfer(baseUrl, ownerHex, recipientHex, intent.amountSun)
+
+            is TronTransactionIntent.Trc20Transfer -> {
+                val contractHex = intent.contractAddress.tronAddressToHexAddress()
+                val parameterHex = Trc20TransferAbi.encodeTransferParameters(recipient, intent.amountSun)
+                val feeLimit = feeLimitFor(presetFee, baseUrl, ownerHex, recipient, contractHex, intent.amountSun)
+
+                tronGridApi.triggerSmartContract(
+                    baseUrl = baseUrl,
+                    ownerHexAddress = ownerHex,
+                    contractHexAddress = contractHex,
+                    functionSelector = Trc20TransferAbi.TRANSFER_FUNCTION_SELECTOR,
+                    parameterHex = parameterHex,
+                    feeLimitSun = feeLimit
+                ).transaction ?: error("TronGrid returned no transaction from triggersmartcontract")
+            }
+        }
+
+        val txHash = signAndBroadcast(baseUrl, unsigned, submittingMetaAccount, ownerAccountId)
+
+        ExtrinsicSubmission(
+            hash = txHash,
+            submissionOrigin = SubmissionOrigin.singleOrigin(ownerAccountId),
+            callExecutionType = CallExecutionType.IMMEDIATE,
+            submissionHierarchy = SubmissionHierarchy(submittingMetaAccount, CallExecutionType.IMMEDIATE)
+        )
+    }
+
+    override suspend fun transactAndAwaitExecution(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipient: AccountId,
+        presetFee: Fee?,
+        intent: TronTransactionIntent
+    ): Result<TransactionExecution> {
+        // Tron transactions execute atomically with inclusion (no separate "prepare" step, same as EVM) - so
+        // successful broadcast is already a strong signal. We do not poll for block confirmation here since
+        // this method sits outside the primary send flow's critical path (`SendInteractor`/`RealSendUseCase`
+        // only ever call `transact`, not this) - see Phase 2 implementation notes for what remains unverified.
+        return transact(chain, origin, recipient, presetFee, intent).map { TransactionExecution.Tron(it.hash) }
+    }
+
+    private suspend fun signAndBroadcast(
+        baseUrl: String,
+        unsigned: TronUnsignedTransactionResponse,
+        metaAccount: MetaAccount,
+        ownerAccountId: AccountId
+    ): String {
+        val rawDataHex = requireNotNull(unsigned.rawDataHex) { "TronGrid returned no raw_data_hex" }
+        val messageHash = rawDataHex.fromHex().sha256()
+
+        check(unsigned.txID == null || messageHash.toHexString(withPrefix = false) == unsigned.txID) {
+            "sha256(raw_data) does not match the txID TronGrid reported - refusing to sign a possibly-tampered transaction"
+        }
+
+        val signer = signerProvider.rootSignerFor(metaAccount)
+        val signedRaw = signer.signRaw(SignerPayloadRaw(message = messageHash, accountId = ownerAccountId, skipMessageHashing = true))
+        val signature = signedRaw.toEcdsaSignatureData()
+
+        // Tron's compact signature format is r(32) + s(32) + v(1), v = 27/28 - byte-for-byte identical to what
+        // web3j's Sign.SignatureData already produces for Ethereum signing (see class doc for verification notes).
+        val signatureBytes = signature.r + signature.s + signature.v
+        val signatureHex = signatureBytes.toHexString(withPrefix = false)
+
+        return tronGridApi.broadcastTransaction(baseUrl, unsigned, signatureHex)
+    }
+
+    private suspend fun feeLimitFor(
+        presetFee: Fee?,
+        baseUrl: String,
+        ownerHex: String,
+        recipient: AccountId,
+        contractHex: String,
+        amountSun: BigInteger
+    ): BigInteger {
+        val estimatedFee = presetFee?.castOrNull<TronFee>()?.amount
+            ?: estimateTrc20FeeFromContractHex(baseUrl, ownerHex, recipient, contractHex, amountSun)
+
+        return (estimatedFee * BigInteger.valueOf(3)).coerceIn(MIN_FEE_LIMIT_SUN, MAX_FEE_LIMIT_SUN)
+    }
+
+    private suspend fun estimateNativeFee(baseUrl: String, ownerHex: String, recipient: AccountId, amountSun: BigInteger): BigInteger {
+        // TronGrid's createtransaction rejects amount=0 outright with a ContractValidateException (confirmed
+        // live) - the send screen's fee loader calls calculateFee reactively as the user types, including before
+        // any amount has been entered. Substitute a minimal placeholder purely for this dry-run construction call;
+        // it does not affect the real amount used when the transfer is actually built in transact().
+        val dryRunAmountSun = amountSun.takeIf { it > BigInteger.ZERO } ?: BigInteger.ONE
+        val unsigned = tronGridApi.createNativeTransfer(baseUrl, ownerHex, recipient.toTronHexAddress(), dryRunAmountSun)
+        val txSizeBytes = requireNotNull(unsigned.rawDataHex) { "TronGrid returned no raw_data_hex" }.length / 2
+
+        val resource = runCatching { tronGridApi.getAccountResource(baseUrl, ownerHex) }.getOrDefault(EMPTY_RESOURCE)
+        val bandwidthPrice = chainParameterOrDefault(baseUrl, TRANSACTION_FEE_PARAM_KEY, FALLBACK_BANDWIDTH_FEE_SUN)
+
+        val bandwidthShortfall = shortfall(txSizeBytes.toLong(), resource.availableBandwidth())
+
+        return bandwidthShortfall.toBigInteger() * bandwidthPrice
+    }
+
+    private suspend fun estimateTrc20FeeFromContractHex(
+        baseUrl: String,
+        ownerHex: String,
+        recipient: AccountId,
+        contractHex: String,
+        amountSun: BigInteger
+    ): BigInteger {
+        val parameterHex = Trc20TransferAbi.encodeTransferParameters(recipient, amountSun)
+
+        val dryRun = runCatching {
+            tronGridApi.triggerConstantContract(baseUrl, ownerHex, contractHex, Trc20TransferAbi.TRANSFER_FUNCTION_SELECTOR, parameterHex)
+        }.getOrNull()
+
+        // A dry-run revert (e.g. the sender doesn't yet hold the token) still reports the energy spent up to the
+        // revert point, which remains a meaningful (if slightly different) estimate - it is used as-is rather
+        // than special-cased, only a wholly-failed HTTP call falls back to the conservative constant.
+        val energyUsed = dryRun?.energyUsed ?: FALLBACK_TRC20_ENERGY_UNITS
+        val txSizeBytes = dryRun?.transaction?.rawDataHex?.let { it.length / 2L } ?: FALLBACK_TRC20_TX_SIZE_BYTES
+
+        val resource = runCatching { tronGridApi.getAccountResource(baseUrl, ownerHex) }.getOrDefault(EMPTY_RESOURCE)
+        val bandwidthPrice = chainParameterOrDefault(baseUrl, TRANSACTION_FEE_PARAM_KEY, FALLBACK_BANDWIDTH_FEE_SUN)
+        val energyPrice = chainParameterOrDefault(baseUrl, ENERGY_FEE_PARAM_KEY, FALLBACK_ENERGY_FEE_SUN)
+
+        val bandwidthShortfall = shortfall(txSizeBytes, resource.availableBandwidth())
+        val energyShortfall = shortfall(energyUsed, resource.availableEnergy())
+
+        return bandwidthShortfall.toBigInteger() * bandwidthPrice + energyShortfall.toBigInteger() * energyPrice
+    }
+
+    private suspend fun chainParameterOrDefault(baseUrl: String, key: String, default: BigInteger): BigInteger {
+        val params = runCatching { tronGridApi.getChainParameters(baseUrl) }.getOrNull()
+
+        return params?.get(key)?.toBigInteger() ?: default
+    }
+
+    private fun shortfall(needed: Long, available: Long): Long = (needed - available.coerceAtLeast(0)).coerceAtLeast(0)
+
+    private fun TronAccountResourceResponse.availableBandwidth(): Long =
+        (freeNetLimit - freeNetUsed).coerceAtLeast(0) + (netLimit - netUsed).coerceAtLeast(0)
+
+    private fun TronAccountResourceResponse.availableEnergy(): Long =
+        (energyLimit - energyUsed).coerceAtLeast(0)
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/transaction/Trc20TransferAbi.kt

@@ -0,0 +1,49 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction
+
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import java.math.BigInteger
+
+/**
+ * Minimal, hand-written Solidity ABI encoding for the two calls this client makes to a TRC-20 contract:
+ * `transfer(address,uint256)` (sending) and `balanceOf(address)` (reading a balance - `Trc20AssetBalance` can't
+ * use TronGrid's `/v1/accounts` REST endpoint for this: a TRC-20 balance lives in the token contract's own
+ * storage, not the holder's Account object, so an address that has only ever received TRC-20 tokens has no
+ * Account object at all and `/v1/accounts` silently returns empty for it regardless of its real balance).
+ *
+ * Both parameter types involved (`address`, `uint256`) are static (fixed-size), so encoding is just "left-pad
+ * each to 32 bytes and concatenate" - no dynamic-type/offset table is needed. The 4-byte function selector is
+ * intentionally NOT computed client-side: TronGrid accepts the human-readable `function_selector` string
+ * directly and hashes it server-side (confirmed live against Shasta testnet - a call with
+ * `function_selector: "transfer(address,uint256)"` and no client-computed selector correctly resolved to the
+ * standard `a9059cbb` selector in the resulting `raw_data`), which avoids needing a keccak256 implementation here.
+ */
+object Trc20TransferAbi {
+
+    const val TRANSFER_FUNCTION_SELECTOR = "transfer(address,uint256)"
+    const val BALANCE_OF_FUNCTION_SELECTOR = "balanceOf(address)"
+
+    /**
+     * @param recipient raw 20-byte Ethereum/Tron-style account id (NOT the `41`-prefixed Tron hex address -
+     * ABI-encoded Solidity `address` parameters use the bare 20-byte form, confirmed live).
+     */
+    fun encodeTransferParameters(recipient: AccountId, amountSun: BigInteger): String {
+        require(recipient.size == 20) { "Tron/EVM-style account id must be 20 bytes, got ${recipient.size}" }
+        require(amountSun.signum() >= 0) { "Amount must not be negative, got $amountSun" }
+
+        val addressParam = recipient.toHexString(withPrefix = false).padStart(64, '0')
+        val amountParam = amountSun.toString(16).padStart(64, '0')
+
+        return addressParam + amountParam
+    }
+
+    /**
+     * @param holder raw 20-byte Ethereum/Tron-style account id - same encoding as [encodeTransferParameters]'s
+     * `recipient`.
+     */
+    fun encodeBalanceOfParameters(holder: AccountId): String {
+        require(holder.size == 20) { "Tron/EVM-style account id must be 20 bytes, got ${holder.size}" }
+
+        return holder.toHexString(withPrefix = false).padStart(64, '0')
+    }
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/transaction/TronTransactionService.kt

@@ -0,0 +1,55 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction
+
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.TransactionOrigin
+import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicSubmission
+import io.novafoundation.nova.feature_account_api.data.model.Fee
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.tranfers.TransactionExecution
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.runtime.AccountId
+import java.math.BigInteger
+
+/**
+ * What kind of Tron transaction to build. Both cases ultimately burn TRX for bandwidth/energy per Tron's default
+ * protocol behavior - this service never stakes/rents Energy or Bandwidth, it only estimates the automatic burn
+ * and lets the caller (asset transfer validation) block the send if the user's TRX balance can't cover it.
+ */
+sealed class TronTransactionIntent {
+
+    class Native(val amountSun: BigInteger) : TronTransactionIntent()
+
+    /** @param contractAddress Base58Check TRC-20 contract address, as stored in chain config (`Type.Trc20.contractAddress`). */
+    class Trc20Transfer(val contractAddress: String, val amountSun: BigInteger) : TronTransactionIntent()
+}
+
+/**
+ * Mirrors [io.novafoundation.nova.feature_account_api.data.ethereum.transaction.EvmTransactionService]'s shape
+ * (calculateFee/transact/transactAndAwaitExecution over a sending origin), but for Tron. Unlike the EVM service,
+ * this lives entirely in `feature-wallet-impl` rather than being split across `feature-account-api`/`-impl`,
+ * since (for now, Phase 2 send-only scope) it is only ever consumed by `TronNativeAssetTransfers`/
+ * `Trc20AssetTransfers` in this module, and it needs [io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi],
+ * which itself lives in this module (feature-account-impl cannot depend on feature-wallet-impl).
+ *
+ * Construction goes through TronGrid's own `/wallet/createtransaction` and `/wallet/triggersmartcontract`
+ * endpoints rather than hand-rolled protobuf encoding - see `RealTronTransactionService` for details and the
+ * live-testnet verification notes.
+ */
+interface TronTransactionService {
+
+    suspend fun calculateFee(chain: Chain, origin: TransactionOrigin, recipient: AccountId, intent: TronTransactionIntent): Fee
+
+    suspend fun transact(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipient: AccountId,
+        presetFee: Fee?,
+        intent: TronTransactionIntent
+    ): Result<ExtrinsicSubmission>
+
+    suspend fun transactAndAwaitExecution(
+        chain: Chain,
+        origin: TransactionOrigin,
+        recipient: AccountId,
+        presetFee: Fee?,
+        intent: TronTransactionIntent
+    ): Result<TransactionExecution>
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/di/WalletFeatureDependencies.kt

@@ -37,6 +37,7 @@ import io.novafoundation.nova.feature_account_api.data.extrinsic.ExtrinsicServic
 import io.novafoundation.nova.feature_account_api.data.fee.FeePaymentProviderRegistry
 import io.novafoundation.nova.feature_account_api.data.fee.capability.CustomFeeCapabilityFacade
 import io.novafoundation.nova.feature_account_api.data.multisig.repository.MultisigValidationsRepository
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
 import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
 import io.novafoundation.nova.feature_account_api.domain.interfaces.SelectedAccountUseCase
 import io.novafoundation.nova.feature_account_api.domain.updaters.AccountUpdateScope
@@ -74,6 +75,8 @@ interface WalletFeatureDependencies {
 
     val evmTransactionService: EvmTransactionService
 
+    val signerProvider: SignerProvider
+
     val chainAssetDao: ChainAssetDao
 
     val storageStorageSharedRequestsBuilderFactory: StorageSharedRequestsBuilderFactory

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/di/modules/AssetsModule.kt

@@ -22,6 +22,7 @@ import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets
         EvmNativeAssetsModule::class,
         EquilibriumAssetsModule::class,
         TronAssetsModule::class,
+        BitcoinAssetsModule::class,
         UnsupportedAssetsModule::class
     ]
 )
@@ -38,6 +39,7 @@ class AssetsModule {
         @EquilibriumAsset equilibrium: Lazy<AssetSource>,
         @TronNativeAssets tronNative: Lazy<AssetSource>,
         @Trc20Assets trc20: Lazy<AssetSource>,
+        @BitcoinNativeAssets bitcoinNative: Lazy<AssetSource>,
         @UnsupportedAssets unsupported: AssetSource,
 
         nativeAssetEventDetector: NativeAssetEventDetector,
@@ -53,6 +55,7 @@ class AssetsModule {
         equilibriumAssetSource = equilibrium,
         tronNativeSource = tronNative,
         trc20Source = trc20,
+        bitcoinNativeSource = bitcoinNative,
         unsupportedBalanceSource = unsupported,
 
         nativeAssetEventDetector = nativeAssetEventDetector,

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/di/modules/BitcoinAssetsModule.kt

@@ -0,0 +1,81 @@
+package io.novafoundation.nova.feature_wallet_impl.di.modules
+
+import dagger.Module
+import dagger.Provides
+import io.novafoundation.nova.common.data.network.NetworkApiCreator
+import io.novafoundation.nova.common.di.scope.FeatureScope
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
+import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
+import io.novafoundation.nova.feature_wallet_api.data.cache.AssetCache
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSource
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSourceRegistry
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.BitcoinApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.RealBitcoinApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.RetrofitBitcoinApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.transaction.BitcoinTransactionService
+import io.novafoundation.nova.feature_wallet_impl.data.network.bitcoin.transaction.RealBitcoinTransactionService
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.StaticAssetSource
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.bitcoinNative.BitcoinNativeAssetBalance
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.history.UnsupportedAssetHistory
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.bitcoinNative.BitcoinNativeAssetTransfers
+import javax.inject.Qualifier
+
+@Qualifier
+annotation class BitcoinNativeAssets
+
+/**
+ * Bitcoin support: `balance` (REST polling against mempool.space) and `transfers` (client-side UTXO selection,
+ * BIP143 signing, raw broadcast - see `RealBitcoinTransactionService` for the full construction/signing notes).
+ *
+ * `history` remains unsupported (out of scope for this phase, same as the rest of the app's `Unsupported*`
+ * stubs used for asset types without history support - see `TronAssetsModule` for the identical precedent).
+ */
+@Module
+class BitcoinAssetsModule {
+
+    @Provides
+    @FeatureScope
+    fun provideRetrofitBitcoinApi(
+        networkApiCreator: NetworkApiCreator
+    ): RetrofitBitcoinApi = networkApiCreator.create(RetrofitBitcoinApi::class.java)
+
+    @Provides
+    @FeatureScope
+    fun provideBitcoinApi(retrofitBitcoinApi: RetrofitBitcoinApi): BitcoinApi = RealBitcoinApi(retrofitBitcoinApi)
+
+    @Provides
+    @FeatureScope
+    fun provideBitcoinTransactionService(
+        accountRepository: AccountRepository,
+        signerProvider: SignerProvider,
+        bitcoinApi: BitcoinApi,
+    ): BitcoinTransactionService = RealBitcoinTransactionService(
+        accountRepository = accountRepository,
+        signerProvider = signerProvider,
+        bitcoinApi = bitcoinApi
+    )
+
+    @Provides
+    @FeatureScope
+    fun provideBitcoinNativeBalance(assetCache: AssetCache, bitcoinApi: BitcoinApi) = BitcoinNativeAssetBalance(assetCache, bitcoinApi)
+
+    @Provides
+    @FeatureScope
+    fun provideBitcoinNativeAssetTransfers(
+        bitcoinTransactionService: BitcoinTransactionService,
+        assetSourceRegistry: AssetSourceRegistry,
+    ) = BitcoinNativeAssetTransfers(bitcoinTransactionService, assetSourceRegistry)
+
+    @Provides
+    @BitcoinNativeAssets
+    @FeatureScope
+    fun provideBitcoinNativeAssetSource(
+        bitcoinNativeAssetBalance: BitcoinNativeAssetBalance,
+        bitcoinNativeAssetTransfers: BitcoinNativeAssetTransfers,
+        unsupportedAssetHistory: UnsupportedAssetHistory,
+    ): AssetSource = StaticAssetSource(
+        transfers = bitcoinNativeAssetTransfers,
+        balance = bitcoinNativeAssetBalance,
+        history = unsupportedAssetHistory
+    )
+}

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/di/modules/TronAssetsModule.kt

@@ -4,16 +4,22 @@ import dagger.Module
 import dagger.Provides
 import io.novafoundation.nova.common.data.network.NetworkApiCreator
 import io.novafoundation.nova.common.di.scope.FeatureScope
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
+import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
 import io.novafoundation.nova.feature_wallet_api.data.cache.AssetCache
 import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSource
+import io.novafoundation.nova.feature_wallet_api.data.network.blockhain.assets.AssetSourceRegistry
 import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.StaticAssetSource
 import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.trc20.Trc20AssetBalance
 import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.balances.tronNative.TronNativeAssetBalance
 import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.history.UnsupportedAssetHistory
-import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.UnsupportedAssetTransfers
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.trc20.Trc20AssetTransfers
+import io.novafoundation.nova.feature_wallet_impl.data.network.blockchain.assets.transfers.tronNative.TronNativeAssetTransfers
 import io.novafoundation.nova.feature_wallet_impl.data.network.tron.RealTronGridApi
 import io.novafoundation.nova.feature_wallet_impl.data.network.tron.RetrofitTronGridApi
 import io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.RealTronTransactionService
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction.TronTransactionService
 import javax.inject.Qualifier
 
 @Qualifier
@@ -23,11 +29,17 @@ annotation class TronNativeAssets
 annotation class Trc20Assets
 
 /**
- * Tron/TRC-20 support - Phase 1, read-only.
+ * Tron/TRC-20 support.
  *
- * Only `balance` is implemented for real; `transfers`/`history` reuse the same `Unsupported*` stubs the rest of
+ * Phase 1 (read-only): `balance`.
- * the app uses for asset types with no send/history support yet (see `UnsupportedAssetsModule`). This is
+ * Phase 2 (send/transfer, this module): `transfers`, via [TronTransactionService] - construction/broadcast
- * intentional: no transaction-building/signing code exists for Tron yet - that is future, separate work.
+ * through TronGrid's own REST endpoints, signing through the app's existing Ethereum-style ECDSA signer (see
+ * `RealTronTransactionService` for the full verification notes). No Energy/Bandwidth staking or rental: only
+ * Tron's default protocol behavior (auto-burning TRX when free resources are insufficient) is estimated and
+ * enforced.
+ *
+ * `history` remains unsupported (out of scope for this phase, same as the rest of the app's `Unsupported*`
+ * stubs used for asset types without history support).
  */
 @Module
 class TronAssetsModule {
@@ -42,6 +54,18 @@ class TronAssetsModule {
     @FeatureScope
     fun provideTronGridApi(retrofitTronGridApi: RetrofitTronGridApi): TronGridApi = RealTronGridApi(retrofitTronGridApi)
 
+    @Provides
+    @FeatureScope
+    fun provideTronTransactionService(
+        accountRepository: AccountRepository,
+        signerProvider: SignerProvider,
+        tronGridApi: TronGridApi,
+    ): TronTransactionService = RealTronTransactionService(
+        accountRepository = accountRepository,
+        signerProvider = signerProvider,
+        tronGridApi = tronGridApi
+    )
+
     @Provides
     @FeatureScope
     fun provideTronNativeBalance(assetCache: AssetCache, tronGridApi: TronGridApi) = TronNativeAssetBalance(assetCache, tronGridApi)
@@ -50,15 +74,29 @@ class TronAssetsModule {
     @FeatureScope
     fun provideTrc20Balance(assetCache: AssetCache, tronGridApi: TronGridApi) = Trc20AssetBalance(assetCache, tronGridApi)
 
+    @Provides
+    @FeatureScope
+    fun provideTronNativeAssetTransfers(
+        tronTransactionService: TronTransactionService,
+        assetSourceRegistry: AssetSourceRegistry,
+    ) = TronNativeAssetTransfers(tronTransactionService, assetSourceRegistry)
+
+    @Provides
+    @FeatureScope
+    fun provideTrc20AssetTransfers(
+        tronTransactionService: TronTransactionService,
+        assetSourceRegistry: AssetSourceRegistry,
+    ) = Trc20AssetTransfers(tronTransactionService, assetSourceRegistry)
+
     @Provides
     @TronNativeAssets
     @FeatureScope
     fun provideTronNativeAssetSource(
         tronNativeAssetBalance: TronNativeAssetBalance,
-        unsupportedAssetTransfers: UnsupportedAssetTransfers,
+        tronNativeAssetTransfers: TronNativeAssetTransfers,
         unsupportedAssetHistory: UnsupportedAssetHistory,
     ): AssetSource = StaticAssetSource(
-        transfers = unsupportedAssetTransfers,
+        transfers = tronNativeAssetTransfers,
         balance = tronNativeAssetBalance,
         history = unsupportedAssetHistory
     )
@@ -68,10 +106,10 @@ class TronAssetsModule {
     @FeatureScope
     fun provideTrc20AssetSource(
         trc20AssetBalance: Trc20AssetBalance,
-        unsupportedAssetTransfers: UnsupportedAssetTransfers,
+        trc20AssetTransfers: Trc20AssetTransfers,
         unsupportedAssetHistory: UnsupportedAssetHistory,
     ): AssetSource = StaticAssetSource(
-        transfers = unsupportedAssetTransfers,
+        transfers = trc20AssetTransfers,
         balance = trc20AssetBalance,
         history = unsupportedAssetHistory
     )

feature-wallet-impl/src/test/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/transaction/RealTronTransactionServiceTest.kt

@@ -0,0 +1,276 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction
+
+import com.google.gson.JsonObject
+import io.novafoundation.nova.common.utils.Precision
+import io.novafoundation.nova.common.utils.TokenSymbol
+import io.novafoundation.nova.common.utils.sha256
+import io.novafoundation.nova.common.utils.toTronHexAddress
+import io.novafoundation.nova.common.utils.tronAddressToAccountId
+import io.novafoundation.nova.feature_account_api.data.ethereum.transaction.TransactionOrigin
+import io.novafoundation.nova.feature_account_api.data.signer.NovaSigner
+import io.novafoundation.nova.feature_account_api.data.signer.SignerProvider
+import io.novafoundation.nova.feature_account_api.domain.interfaces.AccountRepository
+import io.novafoundation.nova.feature_account_api.domain.model.MetaAccount
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.TronGridApi
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronAccountResourceResponse
+import io.novafoundation.nova.feature_wallet_impl.data.network.tron.model.TronUnsignedTransactionResponse
+import io.novafoundation.nova.runtime.multiNetwork.chain.model.Chain
+import io.novasama.substrate_sdk_android.encrypt.SignatureWrapper
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import io.novasama.substrate_sdk_android.extensions.toHexString
+import io.novasama.substrate_sdk_android.runtime.extrinsic.signer.SignedRaw
+import io.novasama.substrate_sdk_android.runtime.extrinsic.signer.SignerPayloadRaw
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatcher
+import org.mockito.Mock
+import org.mockito.Mockito
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+import org.mockito.junit.MockitoJUnitRunner
+import java.math.BigInteger
+
+// eq()/any()/argThat() genuinely return null at runtime - that's how Mockito's matcher-stack recording works,
+// regardless of whether they're called via test_shared's Kotlin wrappers or the raw org.mockito.Mockito statics
+// directly (confirmed: switching to the raw statics did not avoid the "eq(...) must not be null" crash once that
+// null flows into a Kotlin non-null-typed parameter somewhere downstream of the call site). Instead of returning
+// the real (null) value, these local wrappers fall back to a definitely-non-null stand-in - the real value itself
+// for eq() (harmless: the matcher was already recorded on Mockito's thread-local stack by the time this returns,
+// so the fallback value is never actually used for matching) and an unchecked-cast dummy for any()/argThat()
+// (mirrors mockito-kotlin's own internal implementation of the same helpers).
+private fun <T> eq(value: T): T = Mockito.eq(value) ?: value
+
+@Suppress("UNCHECKED_CAST")
+private fun <T> any(): T {
+    Mockito.any<T>()
+    return null as T
+}
+
+@Suppress("UNCHECKED_CAST")
+private fun <T> argThat(matcher: (T) -> Boolean): T {
+    Mockito.argThat(ArgumentMatcher<T> { matcher(it) })
+    return null as T
+}
+
+private fun <T> whenever(methodCall: T?) = Mockito.`when`(methodCall)
+
+/**
+ * Covers the native-TRX branch of [RealTronTransactionService.transact] - the sign/broadcast pipeline this class'
+ * own doc comment describes (sha256(raw_data) signed via the existing Ethereum-style ECDSA-raw-hash primitive,
+ * assembled as a 65-byte r+s+v signature) had no test at all before this: [Trc20TransferAbiTest] only covers the
+ * TRC-20 ABI-encoding side, and [TronDerivationTest]/[io.novafoundation.nova.common.utils.TronAddressTest] only
+ * cover address derivation/formatting, not transaction construction or signing.
+ *
+ * The owner address used throughout is the same one [TronDerivationTest] cross-validated against the standard
+ * BIP39 test mnemonic ("abandon x11 about" at the coin-195 path) and against live TronGrid data - reusing it here
+ * keeps every Tron test in this codebase anchored to a single, independently-verified real-world address instead
+ * of an arbitrary one. The recipient and raw_data_hex/txID pair are self-consistent fixtures created for this
+ * test only (unlike [Trc20TransferAbiTest]'s ABI vector, this raw_data_hex was not captured live against
+ * TronGrid - constructing a real `TransferContract` protobuf is out of scope here, since this class deliberately
+ * never encodes one itself, see its class doc) - what matters for these tests is that this service correctly
+ * hashes/signs/forwards whatever raw_data TronGrid returns, which a self-consistent fixture exercises just as
+ * well as a live-captured one.
+ */
+@RunWith(MockitoJUnitRunner::class)
+class RealTronTransactionServiceTest {
+
+    @Mock
+    lateinit var accountRepository: AccountRepository
+
+    @Mock
+    lateinit var signerProvider: SignerProvider
+
+    @Mock
+    lateinit var tronGridApi: TronGridApi
+
+    @Mock
+    lateinit var metaAccount: MetaAccount
+
+    @Mock
+    lateinit var signer: NovaSigner
+
+    private lateinit var subject: RealTronTransactionService
+
+    private val ownerAccountId = "TUEZSdKsoDHQMeZwihtdoBiN46zxhGWYdH".tronAddressToAccountId()
+    private val ownerHex = ownerAccountId.toTronHexAddress()
+
+    private val recipientAccountId = "dfd8703a5c753e17ed52a96a29cea9d425538dfe".fromHex()
+    private val recipientHex = recipientAccountId.toTronHexAddress()
+
+    private val amountSun = BigInteger.valueOf(1_000_000)
+
+    private val baseUrl = "https://api.trongrid.io"
+    private val chain = tronChain(baseUrl)
+
+    // Self-consistent fixture: rawDataHex ++ its own sha256 as txID - see class doc.
+    private val rawDataHex = "0a027a1e2208d1e2b3f4a5b6c7d840e8c896e8b7325a67080112630a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412320a1541dfd8703a5c753e17ed52a96a29cea9d425538dfe1215415d10da10f5c60a8e2d5e3c0a70e1e7f3c1b2a3e41880ade20470a08fc9c9e8b732"
+    private val expectedTxId = rawDataHex.fromHex().sha256().toHexString(withPrefix = false)
+
+    @Before
+    fun setup() {
+        subject = RealTronTransactionService(accountRepository, signerProvider, tronGridApi)
+
+        whenever(metaAccount.accountIdIn(eq(chain))).thenReturn(ownerAccountId)
+        whenever(signerProvider.rootSignerFor(eq(metaAccount))).thenReturn(signer)
+    }
+
+    @Test
+    fun `transact with Native intent should build, sign with sha256(raw_data), and broadcast a 65-byte r+s+v signature`(): Unit = runBlocking {
+        val unsigned = TronUnsignedTransactionResponse(
+            visible = false,
+            txID = expectedTxId,
+            rawData = JsonObject(),
+            rawDataHex = rawDataHex
+        )
+
+        val r = ByteArray(32) { (it + 1).toByte() }
+        val s = ByteArray(32) { (it + 33).toByte() }
+        val v = byteArrayOf(27)
+        val fakeSignedRaw = SignedRaw(
+            SignerPayloadRaw(message = expectedTxId.fromHex(), accountId = ownerAccountId, skipMessageHashing = true),
+            SignatureWrapper.Ecdsa(v = v, r = r, s = s)
+        )
+
+        whenever(tronGridApi.createNativeTransfer(eq(baseUrl), eq(ownerHex), eq(recipientHex), eq(amountSun))).thenReturn(unsigned)
+        whenever(signer.signRaw(any())).thenReturn(fakeSignedRaw)
+        whenever(tronGridApi.broadcastTransaction(eq(baseUrl), eq(unsigned), any())).thenReturn("some-broadcast-tx-hash")
+
+        val result = subject.transact(
+            chain = chain,
+            origin = TransactionOrigin.Wallet(metaAccount),
+            recipient = recipientAccountId,
+            presetFee = null,
+            intent = TronTransactionIntent.Native(amountSun)
+        )
+
+        assertTrue(result.isSuccess)
+        assertEquals("some-broadcast-tx-hash", result.getOrThrow().hash)
+
+        // The message actually handed to the signer must be sha256(raw_data), not raw_data or txID itself - a
+        // regression here would silently produce a signature over the wrong bytes. ByteArray has reference
+        // equality in Kotlin, so this must compare contents (contentEquals), not rely on SignerPayloadRaw.equals().
+        val expectedMessage = rawDataHex.fromHex().sha256()
+        verify(signer).signRaw(
+            argThat<SignerPayloadRaw> { payload: SignerPayloadRaw ->
+                payload.message.contentEquals(expectedMessage) &&
+                    payload.accountId.contentEquals(ownerAccountId) &&
+                    payload.skipMessageHashing
+            }
+        )
+
+        // Tron expects a flat 65-byte r(32)+s(32)+v(1) hex signature - assembled by hand in production code, not
+        // by any library, so this is the one place that byte order/length could silently regress.
+        val expectedSignatureHex = (r + s + v).toHexString(withPrefix = false)
+        verify(tronGridApi).broadcastTransaction(baseUrl, unsigned, expectedSignatureHex)
+    }
+
+    @Test
+    fun `transact should refuse to sign when TronGrid's txID does not match sha256(raw_data)`(): Unit = runBlocking {
+        val tamperedTxId = "0".repeat(64) // deliberately wrong - does not match sha256(rawDataHex)
+        val unsigned = TronUnsignedTransactionResponse(
+            visible = false,
+            txID = tamperedTxId,
+            rawData = JsonObject(),
+            rawDataHex = rawDataHex
+        )
+
+        whenever(tronGridApi.createNativeTransfer(eq(baseUrl), eq(ownerHex), eq(recipientHex), eq(amountSun))).thenReturn(unsigned)
+
+        val result = subject.transact(
+            chain = chain,
+            origin = TransactionOrigin.Wallet(metaAccount),
+            recipient = recipientAccountId,
+            presetFee = null,
+            intent = TronTransactionIntent.Native(amountSun)
+        )
+
+        assertTrue("expected a failed Result when txID doesn't match sha256(raw_data)", result.isFailure)
+
+        // Signing (and therefore broadcasting) must never be attempted once the txID/raw_data mismatch is
+        // detected - this is the guard that stops a tampered/malicious response from getting silently signed.
+        verify(signer, never()).signRaw(any())
+        verify(tronGridApi, never()).broadcastTransaction(any(), any(), any())
+    }
+
+    @Test
+    fun `calculateFee for Native intent should charge bandwidth shortfall at the fallback price when TronGrid's own resource_endpoints are unavailable`(): Unit = runBlocking {
+        val unsigned = TronUnsignedTransactionResponse(
+            visible = false,
+            txID = expectedTxId,
+            rawData = JsonObject(),
+            rawDataHex = rawDataHex
+        )
+        val txSizeBytes = rawDataHex.length / 2
+
+        whenever(tronGridApi.createNativeTransfer(eq(baseUrl), eq(ownerHex), eq(recipientHex), eq(amountSun))).thenReturn(unsigned)
+        whenever(tronGridApi.getAccountResource(eq(baseUrl), eq(ownerHex))).thenReturn(TronAccountResourceResponse())
+        whenever(tronGridApi.getChainParameters(eq(baseUrl))).thenReturn(emptyMap<String, Long>())
+
+        val fee = subject.calculateFee(
+            chain = chain,
+            origin = TransactionOrigin.Wallet(metaAccount),
+            recipient = recipientAccountId,
+            intent = TronTransactionIntent.Native(amountSun)
+        )
+
+        // Zero available bandwidth (empty TronAccountResourceResponse) -> the whole tx size is billed, at the
+        // fallback bandwidth price (1000 sun/byte) since getChainParameters returned no getTransactionFee entry.
+        val expectedFeeSun = BigInteger.valueOf(txSizeBytes.toLong()) * BigInteger.valueOf(1000)
+        assertEquals(expectedFeeSun, fee.amount)
+    }
+
+    private fun tronChain(baseUrl: String): Chain {
+        val trxAsset = Chain.Asset(
+            icon = null,
+            id = 0,
+            priceId = "tron",
+            chainId = "tron:mainnet",
+            symbol = TokenSymbol("TRX"),
+            precision = Precision(6),
+            buyProviders = emptyMap(),
+            sellProviders = emptyMap(),
+            staking = emptyList(),
+            type = Chain.Asset.Type.TronNative,
+            source = Chain.Asset.Source.DEFAULT,
+            name = "Tron",
+            enabled = true
+        )
+
+        return Chain(
+            id = "tron:mainnet",
+            name = "Tron",
+            assets = listOf(trxAsset),
+            nodes = Chain.Nodes(
+                autoBalanceStrategy = Chain.Nodes.AutoBalanceStrategy.ROUND_ROBIN,
+                wssNodeSelectionStrategy = Chain.Nodes.NodeSelectionStrategy.AutoBalance,
+                nodes = listOf(Chain.Node(chainId = "tron:mainnet", unformattedUrl = baseUrl, name = "TronGrid", orderId = 0, isCustom = false))
+            ),
+            explorers = emptyList(),
+            externalApis = emptyList(),
+            icon = null,
+            addressPrefix = 0,
+            legacyAddressPrefix = null,
+            types = null,
+            isEthereumBased = false,
+            isTronBased = true,
+            isBitcoinBased = false,
+            isTestNet = false,
+            source = Chain.Source.DEFAULT,
+            hasSubstrateRuntime = false,
+            pushSupport = false,
+            hasCrowdloans = false,
+            supportProxy = false,
+            governance = emptyList(),
+            swap = emptyList(),
+            customFee = emptyList(),
+            multisigSupport = false,
+            connectionState = Chain.ConnectionState.FULL_SYNC,
+            parentId = null,
+            additional = null
+        )
+    }
+}

feature-wallet-impl/src/test/java/io/novafoundation/nova/feature_wallet_impl/data/network/tron/transaction/Trc20TransferAbiTest.kt

@@ -0,0 +1,52 @@
+package io.novafoundation.nova.feature_wallet_impl.data.network.tron.transaction
+
+import io.novasama.substrate_sdk_android.extensions.fromHex
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import java.math.BigInteger
+
+class Trc20TransferAbiTest {
+
+    /**
+     * Real request/response pair captured live against TronGrid's Shasta testnet
+     * (`POST https://api.shasta.trongrid.io/wallet/triggerconstantcontract`) for a `transfer(address,uint256)`
+     * call with recipient accountId `dfd8703a5c753e17ed52a96a29cea9d425538dfe` and amount `1000000` (sun) -
+     * TronGrid accepted this exact `parameter` value and correctly resolved `function_selector` to the standard
+     * `a9059cbb` selector in the resulting `raw_data.contract[0].parameter.value.data`.
+     */
+    @Test
+    fun `encodeTransferParameters should match a live-verified TronGrid request`() {
+        val recipient = "dfd8703a5c753e17ed52a96a29cea9d425538dfe".fromHex()
+        val amountSun = BigInteger.valueOf(1_000_000)
+
+        val expectedParameter = "000000000000000000000000dfd8703a5c753e17ed52a96a29cea9d425538dfe" +
+            "00000000000000000000000000000000000000000000000000000000000f4240"
+
+        assertEquals(expectedParameter, Trc20TransferAbi.encodeTransferParameters(recipient, amountSun))
+    }
+
+    @Test
+    fun `encodeTransferParameters should reject a negative amount`() {
+        val recipient = "dfd8703a5c753e17ed52a96a29cea9d425538dfe".fromHex()
+
+        assertThrowsIllegalArgument {
+            Trc20TransferAbi.encodeTransferParameters(recipient, BigInteger.valueOf(-1))
+        }
+    }
+
+    @Test
+    fun `encodeTransferParameters should reject a non-20-byte account id`() {
+        assertThrowsIllegalArgument {
+            Trc20TransferAbi.encodeTransferParameters(ByteArray(19), BigInteger.ONE)
+        }
+    }
+
+    private fun assertThrowsIllegalArgument(block: () -> Unit) {
+        try {
+            block()
+            throw AssertionError("Expected IllegalArgumentException")
+        } catch (expected: IllegalArgumentException) {
+            // expected
+        }
+    }
+}

runtime/build.gradle

@@ -5,17 +5,23 @@ android {
 
     defaultConfig {
 
-        
+        // TEMPORARY - points at pending/post-fix-release, NOT master. wallet-util's master was reset to the
+        // last content the still-live Play Store release can parse (see wallet-util repo history around
+        // 2026-07-11), so master has neither Tron nor Bitcoin config/icons this branch needs to test against.
+        // pending/post-fix-release is where both are staged until wallet-android ships the coordinated release.
+        // MUST be pointed back at "master" before this branch merges - do not ship this override.
 
-        buildConfigField "String", "CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/android/chains.json\""
+        buildConfigField "String", "CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/android/chains.json\""
-        buildConfigField "String", "EVM_ASSETS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/assets/evm/v3/assets.json\""
+        buildConfigField "String", "EVM_ASSETS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/assets/evm/v3/assets.json\""
-        buildConfigField "String", "PRE_CONFIGURED_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/preConfigured/chains.json\""
+        buildConfigField "String", "PRE_CONFIGURED_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/preConfigured/chains.json\""
-        buildConfigField "String", "PRE_CONFIGURED_CHAIN_DETAILS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/preConfigured/details\""
+        buildConfigField "String", "PRE_CONFIGURED_CHAIN_DETAILS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/preConfigured/details\""
 
-        buildConfigField "String", "TEST_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/tests/chains_for_testBalance.json\""
+        buildConfigField "String", "TEST_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/tests/chains_for_testBalance.json\""
+        buildConfigField "String", "TEST_ASSETS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/tests/pezkuwi_assets_for_testBalance.json\""
 
         buildConfigField "String", "INFURA_API_KEY", readStringSecret("INFURA_API_KEY")
         buildConfigField "String", "DWELLIR_API_KEY", readStringSecret("DWELLIR_API_KEY")
+        buildConfigField "String", "TRONGRID_API_KEY", readStringSecret("TRONGRID_API_KEY")
     }
 
     buildTypes {
@@ -27,10 +33,10 @@ android {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
 
-            buildConfigField "String", "CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/android/chains.json\""
+            buildConfigField "String", "CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/android/chains.json\""
-            buildConfigField "String", "EVM_ASSETS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/assets/evm/v3/assets.json\""
+            buildConfigField "String", "EVM_ASSETS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/assets/evm/v3/assets.json\""
-            buildConfigField "String", "PRE_CONFIGURED_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/preConfigured/chains.json\""
+            buildConfigField "String", "PRE_CONFIGURED_CHAINS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/preConfigured/chains.json\""
-            buildConfigField "String", "PRE_CONFIGURED_CHAIN_DETAILS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/master/chains/v22/preConfigured/details\""
+            buildConfigField "String", "PRE_CONFIGURED_CHAIN_DETAILS_URL", "\"https://raw.githubusercontent.com/pezkuwichain/pezkuwi-wallet-utils/pending/post-fix-release/chains/v22/preConfigured/details\""
         }
     }
     namespace 'io.novafoundation.nova.runtime'

runtime/src/main/java/io/novafoundation/nova/runtime/di/ChainRegistryModule.kt

@@ -37,7 +37,9 @@ import io.novafoundation.nova.runtime.multiNetwork.runtime.types.BaseTypeSynchro
 import io.novafoundation.nova.runtime.multiNetwork.runtime.types.TypesFetcher
 import io.novasama.substrate_sdk_android.wsrpc.SocketService
 import kotlinx.coroutines.flow.MutableStateFlow
+import okhttp3.OkHttpClient
 import okhttp3.logging.HttpLoggingInterceptor
+import java.util.concurrent.TimeUnit
 import org.web3j.protocol.http.HttpService
 import javax.inject.Provider
 
@@ -160,12 +162,18 @@ class ChainRegistryModule {
         socketProvider: Provider<SocketService>,
         bulkRetriever: BulkRetriever,
         connectionSecrets: ConnectionSecrets,
-        web3ApiFactory: Web3ApiFactory
+        web3ApiFactory: Web3ApiFactory,
     ) = NodeHealthStateTesterFactory(
         socketProvider,
         connectionSecrets,
         bulkRetriever,
-        web3ApiFactory
+        web3ApiFactory,
+        // A short-lived, minimally-configured client is enough for a health-check ping - unlike Web3ApiFactory's
+        // client, this never needs to survive/reuse connections across a long-lived RPC session.
+        OkHttpClient.Builder()
+            .connectTimeout(10, TimeUnit.SECONDS)
+            .readTimeout(10, TimeUnit.SECONDS)
+            .build()
     )
 
     @Provides

runtime/src/main/java/io/novafoundation/nova/runtime/ext/ChainExt.kt

@@ -9,13 +9,21 @@ import io.novafoundation.nova.common.utils.Modules
 import io.novafoundation.nova.common.utils.TokenSymbol
 import io.novafoundation.nova.common.utils.Urls
 import io.novafoundation.nova.common.utils.asTokenSymbol
+import io.novafoundation.nova.common.utils.bitcoinAddressToAccountId
+import io.novafoundation.nova.common.utils.decodeBitcoinDestination
+import io.novafoundation.nova.common.utils.hash
+import io.novafoundation.nova.common.utils.bitcoinPublicKeyToAccountId
+import io.novafoundation.nova.common.utils.emptyBitcoinAccountId
 import io.novafoundation.nova.common.utils.emptyEthereumAccountId
 import io.novafoundation.nova.common.utils.emptySubstrateAccountId
 import io.novafoundation.nova.common.utils.findIsInstanceOrNull
 import io.novafoundation.nova.common.utils.formatNamed
+import io.novafoundation.nova.common.utils.isValidBitcoinDestinationAddress
 import io.novafoundation.nova.common.utils.removeHexPrefix
 import io.novafoundation.nova.common.utils.emptyTronAccountId
+import io.novafoundation.nova.common.utils.isValidTronAddress
 import io.novafoundation.nova.common.utils.substrateAccountId
+import io.novafoundation.nova.common.utils.toBitcoinAddress
 import io.novafoundation.nova.common.utils.toTronAddress
 import io.novafoundation.nova.common.utils.tronAddressToAccountId
 import io.novafoundation.nova.common.utils.tronPublicKeyToAccountId
@@ -272,6 +280,7 @@ fun Chain.requireGenesisHash() = requireNotNull(genesisHash)
 fun Chain.addressOf(accountId: ByteArray): String {
     return when {
         isTronBased -> accountId.toTronAddress()
+        isBitcoinBased -> accountId.toBitcoinAddress()
         isEthereumBased -> accountId.toEthereumAddress()
         else -> accountId.toAddress(addressPrefix.toShort())
     }
@@ -282,7 +291,7 @@ fun Chain.addressOf(accountId: AccountIdKey): String {
 }
 
 fun Chain.legacyAddressOfOrNull(accountId: ByteArray): String? {
-    return if (isEthereumBased || isTronBased) {
+    return if (isEthereumBased || isTronBased || isBitcoinBased) {
         null
     } else {
         legacyAddressPrefix?.let { accountId.toAddress(it.toShort()) }
@@ -296,6 +305,12 @@ fun ByteArray.toEthereumAddress(): String {
 fun Chain.accountIdOf(address: String): ByteArray {
     return when {
         isTronBased -> address.tronAddressToAccountId()
+        // Falls back to decodeBitcoinDestination() for a valid P2SH/P2PKH address (real exchange withdrawal
+        // addresses were confirmed to be P2SH-only) - this wallet's own address stays native-SegWit-only, but a
+        // SEND destination legitimately isn't. Safe here ONLY because this generic accountId is used for
+        // opaque purposes (identicon generation, presence checks) elsewhere, never fed back into building a
+        // scriptPubKey - see BitcoinDestinationAddress.kt's [hash] doc.
+        isBitcoinBased -> runCatching { address.bitcoinAddressToAccountId() }.getOrElse { address.decodeBitcoinDestination().hash }
         isEthereumBased -> address.asEthereumAddress().toAccountId().value
         else -> address.toAccountId()
     }
@@ -329,6 +344,7 @@ fun Chain.accountIdOrNull(address: String): ByteArray? {
 
 fun Chain.emptyAccountId() = when {
     isTronBased -> emptyTronAccountId()
+    isBitcoinBased -> emptyBitcoinAccountId()
     isEthereumBased -> emptyEthereumAccountId()
     else -> emptySubstrateAccountId()
 }
@@ -342,6 +358,7 @@ fun Chain.accountIdOrDefault(maybeAddress: String): ByteArray {
 fun Chain.accountIdOf(publicKey: ByteArray): ByteArray {
     return when {
         isTronBased -> publicKey.tronPublicKeyToAccountId()
+        isBitcoinBased -> publicKey.bitcoinPublicKeyToAccountId()
         isEthereumBased -> publicKey.asEthereumPublicKey().toAccountId().value
         else -> publicKey.substrateAccountId()
     }
@@ -361,13 +378,24 @@ fun Chain.multiAddressOf(accountId: ByteArray): MultiAddress {
 
 fun Chain.isValidAddress(address: String): Boolean {
     return runCatching {
-        if (isEthereumBased) {
+        when {
-            address.asEthereumAddress().isValid()
+            // Wider than isValidBitcoinAddress() (native SegWit only, used for this wallet's OWN address/accountId):
-        } else {
+            // a valid SEND destination can legitimately be P2SH/P2PKH too - confirmed live via a real exchange
-            address.toAccountId() // verify supplied address can be converted to account id
+            // withdrawal address - see BitcoinDestinationAddress.kt.
+            isBitcoinBased -> address.isValidBitcoinDestinationAddress()
 
-            addressPrefix.toShort() == address.addressPrefix() ||
+            // Tron addresses are Base58Check(0x41 ++ accountId), not SS58 or plain 0x-hex - neither of the two
-                legacyAddressPrefix?.toShort() == address.addressPrefix()
+            // branches below would ever accept them, so this needs its own dedicated check.
+            isTronBased -> address.isValidTronAddress()
+
+            isEthereumBased -> address.asEthereumAddress().isValid()
+
+            else -> {
+                address.toAccountId() // verify supplied address can be converted to account id
+
+                addressPrefix.toShort() == address.addressPrefix() ||
+                    legacyAddressPrefix?.toShort() == address.addressPrefix()
+            }
         }
     }.getOrDefault(false)
 }
@@ -481,6 +509,7 @@ object ChainGeneses {
 object ChainIds {
 
     const val ETHEREUM = "$EIP_155_PREFIX:1"
+    const val TRON = "tron:0x2b6653dc"
 
     const val MOONBEAM = ChainGeneses.MOONBEAM
     const val MOONRIVER = ChainGeneses.MOONRIVER
@@ -492,6 +521,33 @@ val Chain.Companion.Geneses
 val Chain.Companion.Ids
     get() = ChainIds
 
+/**
+ * A short, user-facing token-standard label for chains where disambiguating "which token standard is this"
+ * is actually useful (multiple ecosystems all issue their own USDT/USDC etc., so a bare chain name isn't
+ * always enough context). Deliberately NOT derived from [Chain.Asset.Type] (e.g. every Statemine-type chain
+ * would get the same label) - this is chain-specific by design, matching exactly which labels are
+ * recognizable/expected by users (PEZ-20, ERC-20, TRC-20), not a mechanical one-label-per-asset-type mapping.
+ */
+val Chain.assetStandardLabelOrNull: String?
+    get() = when {
+        genesisHash == Chain.Geneses.PEZKUWI_ASSET_HUB -> "PEZ-20"
+        id == Chain.Ids.ETHEREUM -> "ERC-20"
+        id == Chain.Ids.TRON -> "TRC-20"
+        else -> null
+    }
+
+/**
+ * Chain display name with its token-standard label appended where [assetStandardLabelOrNull] applies, e.g.
+ * "Ethereum (ERC-20)". Shared across every screen that lists the same token symbol once per chain (the
+ * Send/Receive/etc. network picker, the main balance list's per-token chain breakdown) - a bare chain name
+ * alone doesn't convey which issuance this is when multiple ecosystems share the same symbol.
+ */
+fun Chain.displayNameWithAssetStandard(): String {
+    val standardLabel = assetStandardLabelOrNull ?: return name
+
+    return "$name ($standardLabel)"
+}
+
 fun Chain.Asset.requireStatemine(): Type.Statemine {
     require(type is Type.Statemine)
 
@@ -549,6 +605,18 @@ fun Chain.requireTronGridBaseUrl(): String {
     }
 }
 
+/**
+ * The mempool.space-style REST API base url for a Bitcoin-based chain - same rationale as [requireTronGridBaseUrl]:
+ * Bitcoin has no JSON-RPC/WS node concept at all, so the configured `nodes` entry directly *is* the REST API base url.
+ */
+fun Chain.requireMempoolSpaceBaseUrl(): String {
+    require(isBitcoinBased) { "Chain $id is not Bitcoin-based" }
+
+    return requireNotNull(nodes.nodes.minByOrNull { it.orderId }?.unformattedUrl) {
+        "No mempool.space-style node configured for chain $id"
+    }
+}
+
 fun Chain.Asset.requireEquilibrium(): Type.Equilibrium {
     require(type is Type.Equilibrium)
 
@@ -614,6 +682,7 @@ val Chain.Asset.onChainAssetId: String?
         is Type.EvmNative -> null
         is Type.Trc20 -> this.type.contractAddress
         Type.TronNative -> null
+        Type.BitcoinNative -> null
         Type.Unsupported -> error("Unsupported assetId type: ${this.type::class.simpleName}")
     }