Add Tron (TRC20/TRX) send/transfer support

Reuses the existing generic fee-sufficiency validation (sufficientTransferableBalanceToPayOriginFee) and send flow unchanged. Transaction construction goes through TronGrid's own createtransaction/triggersmartcontract endpoints (verified live against Shasta testnet) rather than a hand-rolled protobuf implementation; signing reuses the existing secp256k1 path (SignerPayloadRaw.skipMessageHashing) already used for Ethereum, no new crypto library. Also fixes a Phase 1 gap: Chain.isValidAddress() had no isTronBased branch, so every Tron send would have failed address validation. No Energy staking/delegation/rental UI - only Tron's default protocol behavior (burn TRX to cover Bandwidth/Energy shortfall).
2026-07-22 09:05:48 +00:00 · 2026-07-07 07:08:22 -07:00
parent 46d2a91510
commit 3cd07abe55
16 changed files with 1026 additions and 15 deletions
@@ -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()
@@ -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())
@@ -63,6 +63,19 @@ class SubstrateFee(
    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
@@ -8,4 +8,6 @@ sealed interface TransactionExecution {
    class Ethereum(val ethereumTransactionExecution: EthereumTransactionExecution) : TransactionExecution

    class Substrate(val extrinsicExecutionResult: ExtrinsicExecutionResult) : TransactionExecution
+
+    class Tron(val hash: String) : TransactionExecution
 }
@@ -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)
+    }
+}
@@ -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
+    }
+}
@@ -1,9 +1,20 @@
 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 retrofit2.http.Body
 import retrofit2.http.GET
 import retrofit2.http.Headers
+import retrofit2.http.POST
 import retrofit2.http.Url

 interface RetrofitTronGridApi {
@@ -11,4 +22,28 @@ interface RetrofitTronGridApi {
    @GET
    @Headers(UserAgent.NOVA)
    suspend fun getAccount(@Url url: String): TronAccountResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun createTransaction(@Url url: String, @Body body: TronCreateTransactionRequest): TronUnsignedTransactionResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun triggerConstantContract(@Url url: String, @Body body: TronTriggerContractRequest): TronTriggerContractResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun triggerSmartContract(@Url url: String, @Body body: TronTriggerContractRequest): TronTriggerContractResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun broadcastTransaction(@Url url: String, @Body body: TronBroadcastRequest): TronBroadcastResponse
+
+    @GET
+    @Headers(UserAgent.NOVA)
+    suspend fun getChainParameters(@Url url: String): TronChainParametersResponse
+
+    @POST
+    @Headers(UserAgent.NOVA)
+    suspend fun getAccountResource(@Url url: String, @Body body: TronAddressRequest): TronAccountResourceResponse
 }
@@ -1,13 +1,82 @@
 package io.novafoundation.nova.feature_wallet_impl.data.network.tron

 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.novasama.substrate_sdk_android.extensions.fromHex
 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
+
+    /**
+     * 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(
@@ -29,6 +98,93 @@ class RealTronGridApi(
        return rawBalance?.toBigIntegerOrNull() ?: BigInteger.ZERO
    }

+    override suspend fun createNativeTransfer(baseUrl: String, ownerHexAddress: String, toHexAddress: String, amountSun: BigInteger): TronUnsignedTransactionResponse {
+        val request = TronCreateTransactionRequest(
+            ownerAddress = ownerHexAddress,
+            toAddress = toHexAddress,
+            amount = amountSun.toLongExactOrThrow("amount")
+        )
+
+        val response = 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 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 = 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)
+        )
+
+        val response = 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 retrofitApi.getChainParameters(walletUrl(baseUrl, "getchainparameters"))
+            .chainParameter
+            .associate { it.key to it.value }
+    }
+
+    override suspend fun getAccountResource(baseUrl: String, addressHex: String): TronAccountResourceResponse {
+        return retrofitApi.getAccountResource(walletUrl(baseUrl, "getaccountresource"), TronAddressRequest(address = addressHex))
+    }
+
    private suspend fun fetchAccountData(baseUrl: String, address: String) = retrofitApi.getAccount(
        url = accountUrl(baseUrl, address)
    ).data?.firstOrNull()
@@ -36,4 +192,27 @@ class RealTronGridApi(
    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") }
+    }
 }
@@ -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,
+)
@@ -0,0 +1,252 @@
+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 {
+        val unsigned = tronGridApi.createNativeTransfer(baseUrl, ownerHex, recipient.toTronHexAddress(), amountSun)
+        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)
+}
@@ -0,0 +1,39 @@
+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 single call this client ever makes to a TRC-20 contract:
+ * `transfer(address,uint256)`.
+ *
+ * There is no pre-existing ABI-encoding utility reused here: Phase 1's TRC-20 balance reads
+ * (`Trc20AssetBalance`) go through TronGrid's `/v1/accounts` REST endpoint, not an on-chain `balanceOf` call -
+ * so no prior ABI-encoding code exists in this codebase.
+ *
+ * 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)"
+
+    /**
+     * @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
+    }
+}
@@ -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>
+}
@@ -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
@@ -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
- * the app uses for asset types with no send/history support yet (see `UnsupportedAssetsModule`). This is
- * intentional: no transaction-building/signing code exists for Tron yet - that is future, separate work.
+ * Phase 1 (read-only): `balance`.
+ * Phase 2 (send/transfer, this module): `transfers`, via [TronTransactionService] - construction/broadcast
+ * 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
    )
@@ -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
+        }
+    }
+}
@@ -15,6 +15,7 @@ import io.novafoundation.nova.common.utils.findIsInstanceOrNull
 import io.novafoundation.nova.common.utils.formatNamed
 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.toTronAddress
 import io.novafoundation.nova.common.utils.tronAddressToAccountId
@@ -361,13 +362,19 @@ fun Chain.multiAddressOf(accountId: ByteArray): MultiAddress {

 fun Chain.isValidAddress(address: String): Boolean {
    return runCatching {
-        if (isEthereumBased) {
-            address.asEthereumAddress().isValid()
-        } else {
-            address.toAccountId() // verify supplied address can be converted to account id
+        when {
+            // Tron addresses are Base58Check(0x41 ++ accountId), not SS58 or plain 0x-hex - neither of the two
+            // branches below would ever accept them, so this needs its own dedicated check.
+            isTronBased -> address.isValidTronAddress()

-            addressPrefix.toShort() == address.addressPrefix() ||
-                legacyAddressPrefix?.toShort() == address.addressPrefix()
+            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)
 }