feat: Rebrand Polkadot/Substrate references to PezkuwiChain

This commit systematically rebrands various references from Parity Technologies'
Polkadot/Substrate ecosystem to PezkuwiChain within the kurdistan-sdk.

Key changes include:
- Updated external repository URLs (zombienet-sdk, parity-db, parity-scale-codec, wasm-instrument) to point to pezkuwichain forks.
- Modified internal documentation and code comments to reflect PezkuwiChain naming and structure.
- Replaced direct references to  with  or specific paths within the  for XCM, Pezkuwi, and other modules.
- Cleaned up deprecated  issue and PR references in various  and  files, particularly in  and  modules.
- Adjusted image and logo URLs in documentation to point to PezkuwiChain assets.
- Removed or rephrased comments related to external Polkadot/Substrate PRs and issues.

This is a significant step towards fully customizing the SDK for the PezkuwiChain ecosystem.

pezcumulus/client/relay-chain-rpc-interface/src/rpc_client.rs

@@ -0,0 +1,795 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezcumulus.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// Pezcumulus is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Pezcumulus is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Pezcumulus. If not, see <https://www.gnu.org/licenses/>.
+
+use futures::channel::{
+	mpsc::{Receiver, Sender},
+	oneshot::Sender as OneshotSender,
+};
+use jsonrpsee::{
+	core::{params::ArrayParams, ClientError as JsonRpseeError},
+	rpc_params,
+};
+use prometheus::Registry;
+use serde::{de::DeserializeOwned, Serialize};
+use serde_json::Value as JsonValue;
+use std::collections::{btree_map::BTreeMap, VecDeque};
+use tokio::sync::mpsc::Sender as TokioSender;
+
+use codec::{Decode, Encode};
+
+use cumulus_primitives_core::{
+	relay_chain::{
+		async_backing::{AsyncBackingParams, BackingState, Constraints},
+		slashing, ApprovalVotingParams, BlockNumber, CandidateCommitments, CandidateEvent,
+		CandidateHash, CommittedCandidateReceiptV2 as CommittedCandidateReceipt, CoreIndex,
+		CoreState, DisputeState, ExecutorParams, GroupRotationInfo, Hash as RelayHash,
+		Header as RelayHeader, InboundHrmpMessage, NodeFeatures, OccupiedCoreAssumption,
+		PvfCheckStatement, ScrapedOnChainVotes, SessionIndex, SessionInfo, ValidationCode,
+		ValidationCodeHash, ValidatorId, ValidatorIndex, ValidatorSignature,
+	},
+	InboundDownwardMessage, ParaId, PersistedValidationData,
+};
+use cumulus_relay_chain_interface::{RelayChainError, RelayChainResult};
+
+use pezsc_client_api::StorageData;
+use pezsc_rpc_api::{state::ReadProof, system::Health};
+use pezsc_service::TaskManager;
+use pezsp_consensus_babe::Epoch;
+use pezsp_storage::StorageKey;
+use pezsp_version::RuntimeVersion;
+
+use crate::{metrics::RelaychainRpcMetrics, reconnecting_ws_client::ReconnectingWebsocketWorker};
+pub use url::Url;
+
+const LOG_TARGET: &str = "relay-chain-rpc-client";
+const NOTIFICATION_CHANNEL_SIZE_LIMIT: usize = 20;
+
+/// Messages for communication between [`RelayChainRpcClient`] and the RPC workers.
+#[derive(Debug)]
+pub enum RpcDispatcherMessage {
+	/// Register new listener for the best headers stream. Contains a sender which will be used
+	/// to send incoming headers.
+	RegisterBestHeadListener(Sender<RelayHeader>),
+
+	/// Register new listener for the import headers stream. Contains a sender which will be used
+	/// to send incoming headers.
+	RegisterImportListener(Sender<RelayHeader>),
+
+	/// Register new listener for the finalized headers stream. Contains a sender which will be
+	/// used to send incoming headers.
+	RegisterFinalizationListener(Sender<RelayHeader>),
+
+	/// Register new listener for the finalized headers stream.
+	/// Contains the following:
+	/// - [`String`] representing the RPC method to be called
+	/// - [`ArrayParams`] for the parameters to the RPC call
+	/// - [`OneshotSender`] for the return value of the request
+	Request(String, ArrayParams, OneshotSender<Result<JsonValue, JsonRpseeError>>),
+}
+
+/// Entry point to create [`RelayChainRpcClient`] and start a worker that communicates
+/// to JsonRPC servers over the network.
+pub async fn create_client_and_start_worker(
+	urls: Vec<Url>,
+	task_manager: &mut TaskManager,
+	prometheus_registry: Option<&Registry>,
+) -> RelayChainResult<RelayChainRpcClient> {
+	let (worker, sender) = ReconnectingWebsocketWorker::new(urls).await;
+
+	task_manager
+		.spawn_essential_handle()
+		.spawn("relay-chain-rpc-worker", None, worker.run());
+
+	let client = RelayChainRpcClient::new(sender, prometheus_registry);
+
+	Ok(client)
+}
+
+#[derive(Serialize)]
+struct PayloadToHex<'a>(#[serde(with = "pezsp_core::bytes")] &'a [u8]);
+
+/// Client that maps RPC methods and deserializes results
+#[derive(Clone)]
+pub struct RelayChainRpcClient {
+	/// Sender to send messages to the worker.
+	worker_channel: TokioSender<RpcDispatcherMessage>,
+	metrics: Option<RelaychainRpcMetrics>,
+}
+
+impl RelayChainRpcClient {
+	/// Initialize new RPC Client.
+	///
+	/// This client expects a channel connected to a worker that processes
+	/// requests sent via this channel.
+	pub(crate) fn new(
+		worker_channel: TokioSender<RpcDispatcherMessage>,
+		prometheus_registry: Option<&Registry>,
+	) -> Self {
+		RelayChainRpcClient {
+			worker_channel,
+			metrics: prometheus_registry
+				.and_then(|inner| RelaychainRpcMetrics::register(inner).map_err(|err| {
+					tracing::warn!(target: LOG_TARGET, error = %err, "Unable to instantiate the RPC client metrics, continuing w/o metrics setup.");
+				}).ok()),
+		}
+	}
+
+	/// Same as `call_remote_runtime_function` but work on encoded data
+	pub async fn call_remote_runtime_function_encoded(
+		&self,
+		method_name: &str,
+		hash: RelayHash,
+		payload: &[u8],
+	) -> RelayChainResult<pezsp_core::Bytes> {
+		let payload = PayloadToHex(payload);
+
+		let params = rpc_params! {
+			method_name,
+			payload,
+			hash
+		};
+
+		self.request_tracing::<pezsp_core::Bytes, _>("state_call", params, |err| {
+			tracing::trace!(
+				target: LOG_TARGET,
+				%method_name,
+				%hash,
+				error = %err,
+				"Error during call to 'state_call'.",
+			);
+		})
+		.await
+	}
+
+	/// Call a call to `state_call` rpc method.
+	pub async fn call_remote_runtime_function<R: Decode>(
+		&self,
+		method_name: &str,
+		hash: RelayHash,
+		payload: Option<impl Encode>,
+	) -> RelayChainResult<R> {
+		let payload_bytes =
+			payload.map_or(pezsp_core::Bytes(Vec::new()), |v| pezsp_core::Bytes(v.encode()));
+		let res = self
+			.call_remote_runtime_function_encoded(method_name, hash, &payload_bytes)
+			.await?;
+		Decode::decode(&mut &*res.0).map_err(Into::into)
+	}
+
+	/// Perform RPC request
+	async fn request<'a, R>(
+		&self,
+		method: &'a str,
+		params: ArrayParams,
+	) -> Result<R, RelayChainError>
+	where
+		R: DeserializeOwned + std::fmt::Debug,
+	{
+		self.request_tracing(
+			method,
+			params,
+			|e| tracing::trace!(target:LOG_TARGET, error = %e, %method, "Unable to complete RPC request"),
+		)
+		.await
+	}
+
+	/// Perform RPC request
+	async fn request_tracing<'a, R, OR>(
+		&self,
+		method: &'a str,
+		params: ArrayParams,
+		trace_error: OR,
+	) -> Result<R, RelayChainError>
+	where
+		R: DeserializeOwned + std::fmt::Debug,
+		OR: Fn(&RelayChainError),
+	{
+		let _timer = self.metrics.as_ref().map(|inner| inner.start_request_timer(method));
+
+		let (tx, rx) = futures::channel::oneshot::channel();
+
+		let message = RpcDispatcherMessage::Request(method.into(), params, tx);
+		self.worker_channel.send(message).await.map_err(|err| {
+			RelayChainError::WorkerCommunicationError(format!(
+				"Unable to send message to RPC worker: {}",
+				err
+			))
+		})?;
+
+		let value = rx.await.map_err(|err| {
+			RelayChainError::WorkerCommunicationError(format!(
+				"RPC worker channel closed. This can hint and connectivity issues with the supplied RPC endpoints. Message: {}",
+				err
+			))
+		})??;
+
+		serde_json::from_value(value).map_err(|_| {
+			trace_error(&RelayChainError::GenericError("Unable to deserialize value".to_string()));
+			RelayChainError::RpcCallError(method.to_string())
+		})
+	}
+
+	/// Returns information regarding the current epoch.
+	pub async fn babe_api_current_epoch(&self, at: RelayHash) -> Result<Epoch, RelayChainError> {
+		self.call_remote_runtime_function("BabeApi_current_epoch", at, None::<()>).await
+	}
+
+	/// Scrape dispute relevant from on-chain, backing votes and resolved disputes.
+	pub async fn teyrchain_host_on_chain_votes(
+		&self,
+		at: RelayHash,
+	) -> Result<Option<ScrapedOnChainVotes<RelayHash>>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_on_chain_votes", at, None::<()>)
+			.await
+	}
+
+	/// Returns code hashes of PVFs that require pre-checking by validators in the active set.
+	pub async fn teyrchain_host_pvfs_require_precheck(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<ValidationCodeHash>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_pvfs_require_precheck", at, None::<()>)
+			.await
+	}
+
+	/// Submits a PVF pre-checking statement into the transaction pool.
+	pub async fn teyrchain_host_submit_pvf_check_statement(
+		&self,
+		at: RelayHash,
+		stmt: PvfCheckStatement,
+		signature: ValidatorSignature,
+	) -> Result<(), RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_submit_pvf_check_statement",
+			at,
+			Some((stmt, signature)),
+		)
+		.await
+	}
+
+	/// Get system health information
+	pub async fn system_health(&self) -> Result<Health, RelayChainError> {
+		self.request("system_health", rpc_params![]).await
+	}
+
+	/// Get read proof for `storage_keys`
+	pub async fn state_get_read_proof(
+		&self,
+		storage_keys: Vec<StorageKey>,
+		at: Option<RelayHash>,
+	) -> Result<ReadProof<RelayHash>, RelayChainError> {
+		let params = rpc_params![storage_keys, at];
+		self.request("state_getReadProof", params).await
+	}
+
+	/// Retrieve storage item at `storage_key`
+	pub async fn state_get_storage(
+		&self,
+		storage_key: StorageKey,
+		at: Option<RelayHash>,
+	) -> Result<Option<StorageData>, RelayChainError> {
+		let params = rpc_params![storage_key, at];
+		self.request("state_getStorage", params).await
+	}
+
+	/// Get hash of the n-th block in the canon chain.
+	///
+	/// By default returns latest block hash.
+	pub async fn chain_get_head(&self, at: Option<u64>) -> Result<RelayHash, RelayChainError> {
+		let params = rpc_params![at];
+		self.request("chain_getHead", params).await
+	}
+
+	/// Returns the validator groups and rotation info localized based on the hypothetical child
+	///  of a block whose state  this is invoked on. Note that `now` in the `GroupRotationInfo`
+	/// should be the successor of the number of the block.
+	pub async fn teyrchain_host_validator_groups(
+		&self,
+		at: RelayHash,
+	) -> Result<(Vec<Vec<ValidatorIndex>>, GroupRotationInfo), RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_validator_groups", at, None::<()>)
+			.await
+	}
+
+	/// Get a vector of events concerning candidates that occurred within a block.
+	pub async fn teyrchain_host_candidate_events(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<CandidateEvent>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_candidate_events", at, None::<()>)
+			.await
+	}
+
+	/// Checks if the given validation outputs pass the acceptance criteria.
+	pub async fn teyrchain_host_check_validation_outputs(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		outputs: CandidateCommitments,
+	) -> Result<bool, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_check_validation_outputs",
+			at,
+			Some((para_id, outputs)),
+		)
+		.await
+	}
+
+	/// Returns the persisted validation data for the given `ParaId` along with the corresponding
+	/// validation code hash. Instead of accepting assumption about the para, matches the validation
+	/// data hash against an expected one and yields `None` if they're not equal.
+	pub async fn teyrchain_host_assumed_validation_data(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		expected_hash: RelayHash,
+	) -> Result<Option<(PersistedValidationData, ValidationCodeHash)>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_persisted_assumed_validation_data",
+			at,
+			Some((para_id, expected_hash)),
+		)
+		.await
+	}
+
+	/// Get hash of last finalized block.
+	pub async fn chain_get_finalized_head(&self) -> Result<RelayHash, RelayChainError> {
+		self.request("chain_getFinalizedHead", rpc_params![]).await
+	}
+
+	/// Get hash of n-th block.
+	pub async fn chain_get_block_hash(
+		&self,
+		block_number: Option<BlockNumber>,
+	) -> Result<Option<RelayHash>, RelayChainError> {
+		let params = rpc_params![block_number];
+		self.request("chain_getBlockHash", params).await
+	}
+
+	/// Yields the persisted validation data for the given `ParaId` along with an assumption that
+	/// should be used if the para currently occupies a core.
+	///
+	/// Returns `None` if either the para is not registered or the assumption is `Freed`
+	/// and the para already occupies a core.
+	pub async fn teyrchain_host_persisted_validation_data(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		occupied_core_assumption: OccupiedCoreAssumption,
+	) -> Result<Option<PersistedValidationData>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_persisted_validation_data",
+			at,
+			Some((para_id, occupied_core_assumption)),
+		)
+		.await
+	}
+
+	/// Get the validation code from its hash.
+	pub async fn teyrchain_host_validation_code_by_hash(
+		&self,
+		at: RelayHash,
+		validation_code_hash: ValidationCodeHash,
+	) -> Result<Option<ValidationCode>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_validation_code_by_hash",
+			at,
+			Some(validation_code_hash),
+		)
+		.await
+	}
+
+	/// Yields information on all availability cores as relevant to the child block.
+	/// Cores are either free or occupied. Free cores can have paras assigned to them.
+	pub async fn teyrchain_host_availability_cores(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<CoreState<RelayHash, BlockNumber>>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_availability_cores", at, None::<()>)
+			.await
+	}
+
+	/// Get runtime version
+	pub async fn runtime_version(&self, at: RelayHash) -> Result<RuntimeVersion, RelayChainError> {
+		let params = rpc_params![at];
+		self.request("state_getRuntimeVersion", params).await
+	}
+
+	/// Returns all onchain disputes.
+	pub async fn teyrchain_host_disputes(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<(SessionIndex, CandidateHash, DisputeState<BlockNumber>)>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_disputes", at, None::<()>)
+			.await
+	}
+
+	/// Returns a list of validators that lost a past session dispute and need to be slashed.
+	///
+	/// This is a staging method! Do not use on production runtimes!
+	pub async fn teyrchain_host_unapplied_slashes(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<(SessionIndex, CandidateHash, slashing::LegacyPendingSlashes)>, RelayChainError>
+	{
+		self.call_remote_runtime_function("TeyrchainHost_unapplied_slashes", at, None::<()>)
+			.await
+	}
+
+	/// Returns a list of validators that lost a past session dispute and need to be slashed.
+	pub async fn teyrchain_host_unapplied_slashes_v2(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<(SessionIndex, CandidateHash, slashing::PendingSlashes)>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_unapplied_slashes_v2", at, None::<()>)
+			.await
+	}
+
+	/// Returns a merkle proof of a validator session key in a past session.
+	///
+	/// This is a staging method! Do not use on production runtimes!
+	pub async fn teyrchain_host_key_ownership_proof(
+		&self,
+		at: RelayHash,
+		validator_id: ValidatorId,
+	) -> Result<Option<slashing::OpaqueKeyOwnershipProof>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_key_ownership_proof",
+			at,
+			Some(validator_id),
+		)
+		.await
+	}
+
+	/// Submits an unsigned extrinsic to slash validators who lost a dispute about
+	/// a candidate of a past session.
+	///
+	/// This is a staging method! Do not use on production runtimes!
+	pub async fn teyrchain_host_submit_report_dispute_lost(
+		&self,
+		at: RelayHash,
+		dispute_proof: slashing::DisputeProof,
+		key_ownership_proof: slashing::OpaqueKeyOwnershipProof,
+	) -> Result<Option<()>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_submit_report_dispute_lost",
+			at,
+			Some((dispute_proof, key_ownership_proof)),
+		)
+		.await
+	}
+
+	pub async fn authority_discovery_authorities(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<pezsp_authority_discovery::AuthorityId>, RelayChainError> {
+		self.call_remote_runtime_function("AuthorityDiscoveryApi_authorities", at, None::<()>)
+			.await
+	}
+
+	/// Fetch the validation code used by a para, making the given `OccupiedCoreAssumption`.
+	///
+	/// Returns `None` if either the para is not registered or the assumption is `Freed`
+	/// and the para already occupies a core.
+	pub async fn teyrchain_host_validation_code(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		occupied_core_assumption: OccupiedCoreAssumption,
+	) -> Result<Option<ValidationCode>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_validation_code",
+			at,
+			Some((para_id, occupied_core_assumption)),
+		)
+		.await
+	}
+
+	/// Fetch the hash of the validation code used by a para, making the given
+	/// `OccupiedCoreAssumption`.
+	pub async fn teyrchain_host_validation_code_hash(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		occupied_core_assumption: OccupiedCoreAssumption,
+	) -> Result<Option<ValidationCodeHash>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_validation_code_hash",
+			at,
+			Some((para_id, occupied_core_assumption)),
+		)
+		.await
+	}
+
+	/// Get the session info for the given session, if stored.
+	pub async fn teyrchain_host_session_info(
+		&self,
+		at: RelayHash,
+		index: SessionIndex,
+	) -> Result<Option<SessionInfo>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_session_info", at, Some(index))
+			.await
+	}
+
+	/// Get the executor parameters for the given session, if stored
+	pub async fn teyrchain_host_session_executor_params(
+		&self,
+		at: RelayHash,
+		session_index: SessionIndex,
+	) -> Result<Option<ExecutorParams>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_session_executor_params",
+			at,
+			Some(session_index),
+		)
+		.await
+	}
+
+	/// Get header at specified hash
+	pub async fn chain_get_header(
+		&self,
+		hash: Option<RelayHash>,
+	) -> Result<Option<RelayHeader>, RelayChainError> {
+		let params = rpc_params![hash];
+		self.request("chain_getHeader", params).await
+	}
+
+	/// Get the receipt of a candidate pending availability. This returns `Some` for any paras
+	/// assigned to occupied cores in `availability_cores` and `None` otherwise.
+	pub async fn teyrchain_host_candidate_pending_availability(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+	) -> Result<Option<CommittedCandidateReceipt>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_candidate_pending_availability",
+			at,
+			Some(para_id),
+		)
+		.await
+	}
+
+	/// Returns the session index expected at a child of the block.
+	///
+	/// This can be used to instantiate a `SigningContext`.
+	pub async fn teyrchain_host_session_index_for_child(
+		&self,
+		at: RelayHash,
+	) -> Result<SessionIndex, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_session_index_for_child", at, None::<()>)
+			.await
+	}
+
+	/// Get the current validators.
+	pub async fn teyrchain_host_validators(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<ValidatorId>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_validators", at, None::<()>)
+			.await
+	}
+
+	/// Get the contents of all channels addressed to the given recipient. Channels that have no
+	/// messages in them are also included.
+	pub async fn teyrchain_host_inbound_hrmp_channels_contents(
+		&self,
+		para_id: ParaId,
+		at: RelayHash,
+	) -> Result<BTreeMap<ParaId, Vec<InboundHrmpMessage>>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_inbound_hrmp_channels_contents",
+			at,
+			Some(para_id),
+		)
+		.await
+	}
+
+	/// Get all the pending inbound messages in the downward message queue for a para.
+	pub async fn teyrchain_host_dmq_contents(
+		&self,
+		para_id: ParaId,
+		at: RelayHash,
+	) -> Result<Vec<InboundDownwardMessage>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_dmq_contents", at, Some(para_id))
+			.await
+	}
+
+	/// Get the minimum number of backing votes for a candidate.
+	pub async fn teyrchain_host_minimum_backing_votes(
+		&self,
+		at: RelayHash,
+		_session_index: SessionIndex,
+	) -> Result<u32, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_minimum_backing_votes", at, None::<()>)
+			.await
+	}
+
+	pub async fn teyrchain_host_node_features(
+		&self,
+		at: RelayHash,
+	) -> Result<NodeFeatures, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_node_features", at, None::<()>)
+			.await
+	}
+
+	pub async fn teyrchain_host_disabled_validators(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<ValidatorIndex>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_disabled_validators", at, None::<()>)
+			.await
+	}
+
+	#[allow(missing_docs)]
+	pub async fn teyrchain_host_async_backing_params(
+		&self,
+		at: RelayHash,
+	) -> Result<AsyncBackingParams, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_async_backing_params", at, None::<()>)
+			.await
+	}
+
+	#[allow(missing_docs)]
+	pub async fn teyrchain_host_staging_approval_voting_params(
+		&self,
+		at: RelayHash,
+		_session_index: SessionIndex,
+	) -> Result<ApprovalVotingParams, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_staging_approval_voting_params",
+			at,
+			None::<()>,
+		)
+		.await
+	}
+
+	pub async fn teyrchain_host_para_backing_state(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+	) -> Result<Option<BackingState>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_para_backing_state", at, Some(para_id))
+			.await
+	}
+
+	pub async fn teyrchain_host_claim_queue(
+		&self,
+		at: RelayHash,
+	) -> Result<BTreeMap<CoreIndex, VecDeque<ParaId>>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_claim_queue", at, None::<()>)
+			.await
+	}
+
+	/// Get the receipt of all candidates pending availability.
+	pub async fn teyrchain_host_candidates_pending_availability(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+	) -> Result<Vec<CommittedCandidateReceipt>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_candidates_pending_availability",
+			at,
+			Some(para_id),
+		)
+		.await
+	}
+
+	pub async fn teyrchain_host_scheduling_lookahead(
+		&self,
+		at: RelayHash,
+	) -> Result<u32, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_scheduling_lookahead", at, None::<()>)
+			.await
+	}
+
+	pub async fn teyrchain_host_validation_code_bomb_limit(
+		&self,
+		at: RelayHash,
+	) -> Result<u32, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_validation_code_bomb_limit",
+			at,
+			None::<()>,
+		)
+		.await
+	}
+
+	pub async fn validation_code_hash(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+		occupied_core_assumption: OccupiedCoreAssumption,
+	) -> Result<Option<ValidationCodeHash>, RelayChainError> {
+		self.call_remote_runtime_function(
+			"TeyrchainHost_validation_code_hash",
+			at,
+			Some((para_id, occupied_core_assumption)),
+		)
+		.await
+	}
+
+	pub async fn teyrchain_host_backing_constraints(
+		&self,
+		at: RelayHash,
+		para_id: ParaId,
+	) -> Result<Option<Constraints>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_backing_constraints", at, Some(para_id))
+			.await
+	}
+
+	fn send_register_message_to_worker(
+		&self,
+		message: RpcDispatcherMessage,
+	) -> Result<(), RelayChainError> {
+		self.worker_channel
+			.try_send(message)
+			.map_err(|e| RelayChainError::WorkerCommunicationError(e.to_string()))
+	}
+
+	/// Get a stream of all imported relay chain headers
+	pub fn get_imported_heads_stream(&self) -> Result<Receiver<RelayHeader>, RelayChainError> {
+		let (tx, rx) =
+			futures::channel::mpsc::channel::<RelayHeader>(NOTIFICATION_CHANNEL_SIZE_LIMIT);
+		self.send_register_message_to_worker(RpcDispatcherMessage::RegisterImportListener(tx))?;
+		Ok(rx)
+	}
+
+	/// Get a stream of new best relay chain headers
+	pub fn get_best_heads_stream(&self) -> Result<Receiver<RelayHeader>, RelayChainError> {
+		let (tx, rx) =
+			futures::channel::mpsc::channel::<RelayHeader>(NOTIFICATION_CHANNEL_SIZE_LIMIT);
+		self.send_register_message_to_worker(RpcDispatcherMessage::RegisterBestHeadListener(tx))?;
+		Ok(rx)
+	}
+
+	/// Get a stream of finalized relay chain headers
+	pub fn get_finalized_heads_stream(&self) -> Result<Receiver<RelayHeader>, RelayChainError> {
+		let (tx, rx) =
+			futures::channel::mpsc::channel::<RelayHeader>(NOTIFICATION_CHANNEL_SIZE_LIMIT);
+		self.send_register_message_to_worker(RpcDispatcherMessage::RegisterFinalizationListener(
+			tx,
+		))?;
+		Ok(rx)
+	}
+
+	pub async fn teyrchain_host_para_ids(
+		&self,
+		at: RelayHash,
+	) -> Result<Vec<ParaId>, RelayChainError> {
+		self.call_remote_runtime_function("TeyrchainHost_para_ids", at, None::<()>)
+			.await
+	}
+}
+
+/// Send `header` through all channels contained in `senders`.
+/// If no one is listening to the sender, it is removed from the vector.
+pub fn distribute_header(header: RelayHeader, senders: &mut Vec<Sender<RelayHeader>>) {
+	senders.retain_mut(|e| {
+				match e.try_send(header.clone()) {
+					// Receiver has been dropped, remove Sender from list.
+					Err(error) if error.is_disconnected() => false,
+					// Channel is full. This should not happen.
+					// TODO: Improve error handling here
+					// https://github.com/pezkuwichain/kurdistan-sdk/issues/90
+					Err(error) => {
+						tracing::error!(target: LOG_TARGET, ?error, "Event distribution channel has reached its limit. This can lead to missed notifications.");
+						true
+					},
+					_ => true,
+				}
+			});
+}