diff --git a/Cargo.lock b/Cargo.lock
index d969ea3cdef8..dc0d59344bda 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5159,6 +5159,7 @@ dependencies = [
  "sp-core",
  "sp-externalities",
  "sp-io",
+ "sp-runtime",
  "sp-std",
  "sp-wasm-interface",
 ]
@@ -5509,6 +5510,7 @@ dependencies = [
  "sp-offchain",
  "sp-runtime",
  "sp-session",
+ "sp-storage",
  "sp-transaction-pool",
  "sp-trie",
  "substrate-prometheus-endpoint",
diff --git a/node/service/Cargo.toml b/node/service/Cargo.toml
index cf2dc0549a20..45eb7826caac 100644
--- a/node/service/Cargo.toml
+++ b/node/service/Cargo.toml
@@ -31,6 +31,7 @@ sc-chain-spec = { git = "https://github.com/paritytech/substrate", branch = "mas
 sc-executor = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-consensus = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-network = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sp-storage = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-trie = { git = "https://github.com/paritytech/substrate", branch = "master" }
 consensus_common = { package = "sp-consensus", git = "https://github.com/paritytech/substrate", branch = "master" }
 grandpa = { package = "sc-finality-grandpa", git = "https://github.com/paritytech/substrate", branch = "master" }
diff --git a/node/service/src/client.rs b/node/service/src/client.rs
index 28d2bccabbe5..2b596c9f1f34 100644
--- a/node/service/src/client.rs
+++ b/node/service/src/client.rs
@@ -16,38 +16,335 @@
 
 //! Polkadot Client meta trait
 
-use sp_api::{ProvideRuntimeApi, ConstructRuntimeApi, CallApiAt};
+use std::sync::Arc;
+use sp_api::{ProvideRuntimeApi, CallApiAt, NumberFor};
 use sp_blockchain::HeaderBackend;
-use sp_runtime::traits::Block as BlockT;
-use sc_client_api::{Backend as BackendT, BlockchainEvents};
+use sp_runtime::{
+	Justification, generic::{BlockId, SignedBlock}, traits::{Block as BlockT, BlakeTwo256},
+};
+use sc_client_api::{Backend as BackendT, BlockchainEvents, KeyIterator};
+use sp_storage::{StorageData, StorageKey, ChildInfo, PrefixedStorageKey};
+use polkadot_primitives::v1::{Block, ParachainHost, AccountId, Nonce, Balance};
+use consensus_common::BlockStatus;
 
-/// Polkadot client abstraction, this super trait only pulls in functionality required for
-/// polkadot internal crates like polkadot-collator.
-pub trait PolkadotClient<Block, Backend, Runtime>:
+/// A set of APIs that polkadot-like runtimes must implement.
+pub trait RuntimeApiCollection:
+	sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>
+	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
+	+ babe_primitives::BabeApi<Block>
+	+ grandpa_primitives::GrandpaApi<Block>
+	+ ParachainHost<Block>
+	+ sp_block_builder::BlockBuilder<Block>
+	+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
+	+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
+	+ sp_api::Metadata<Block>
+	+ sp_offchain::OffchainWorkerApi<Block>
+	+ sp_session::SessionKeys<Block>
+	+ authority_discovery_primitives::AuthorityDiscoveryApi<Block>
+where
+	<Self as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<BlakeTwo256>,
+{}
+
+impl<Api> RuntimeApiCollection for Api
+where
+	Api: sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>
+		+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
+		+ babe_primitives::BabeApi<Block>
+		+ grandpa_primitives::GrandpaApi<Block>
+		+ ParachainHost<Block>
+		+ sp_block_builder::BlockBuilder<Block>
+		+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
+		+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
+		+ sp_api::Metadata<Block>
+		+ sp_offchain::OffchainWorkerApi<Block>
+		+ sp_session::SessionKeys<Block>
+		+ authority_discovery_primitives::AuthorityDiscoveryApi<Block>,
+	<Self as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<BlakeTwo256>,
+{}
+
+/// Trait that abstracts over all available client implementations.
+///
+/// For a concrete type there exists [`Client`].
+pub trait AbstractClient<Block, Backend>:
 	BlockchainEvents<Block> + Sized + Send + Sync
-	+ ProvideRuntimeApi<Block, Api = Runtime::RuntimeApi>
+	+ ProvideRuntimeApi<Block>
 	+ HeaderBackend<Block>
 	+ CallApiAt<
 		Block,
 		Error = sp_blockchain::Error,
-		StateBackend = Backend ::State
+		StateBackend = Backend::State
 	>
 	where
 		Block: BlockT,
 		Backend: BackendT<Block>,
-		Runtime: ConstructRuntimeApi<Block, Self>
+		Backend::State: sp_api::StateBackend<BlakeTwo256>,
+		Self::Api: RuntimeApiCollection<StateBackend = Backend::State>,
 {}
 
-impl<Block, Backend, Runtime, Client> PolkadotClient<Block, Backend, Runtime> for Client
+impl<Block, Backend, Client> AbstractClient<Block, Backend> for Client
 	where
 		Block: BlockT,
-		Runtime: ConstructRuntimeApi<Block, Self>,
 		Backend: BackendT<Block>,
-		Client: BlockchainEvents<Block> + ProvideRuntimeApi<Block, Api = Runtime::RuntimeApi> + HeaderBackend<Block>
+		Backend::State: sp_api::StateBackend<BlakeTwo256>,
+		Client: BlockchainEvents<Block> + ProvideRuntimeApi<Block> + HeaderBackend<Block>
 			+ Sized + Send + Sync
 			+ CallApiAt<
 				Block,
 				Error = sp_blockchain::Error,
-				StateBackend = Backend ::State
-			>
+				StateBackend = Backend::State
+			>,
+		Client::Api: RuntimeApiCollection<StateBackend = Backend::State>,
 {}
+
+/// Execute something with the client instance.
+///
+/// As there exist multiple chains inside Polkadot, like Polkadot itself, Kusama, Westend etc,
+/// there can exist different kinds of client types. As these client types differ in the generics
+/// that are being used, we can not easily return them from a function. For returning them from a
+/// function there exists [`Client`]. However, the problem on how to use this client instance still
+/// exists. This trait "solves" it in a dirty way. It requires a type to implement this trait and
+/// than the [`execute_with_client`](ExecuteWithClient::execute_with_client) function can be called
+/// with any possible client instance.
+///
+/// In a perfect world, we could make a closure work in this way.
+pub trait ExecuteWithClient {
+	/// The return type when calling this instance.
+	type Output;
+
+	/// Execute whatever should be executed with the given client instance.
+	fn execute_with_client<Client, Api, Backend>(self, client: Arc<Client>) -> Self::Output
+		where
+			<Api as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<BlakeTwo256>,
+			Backend: sc_client_api::Backend<Block>,
+			Backend::State: sp_api::StateBackend<BlakeTwo256>,
+			Api: crate::RuntimeApiCollection<StateBackend = Backend::State>,
+			Client: AbstractClient<Block, Backend, Api = Api> + 'static;
+}
+
+/// A handle to a Polkadot client instance.
+///
+/// The Polkadot service supports multiple different runtimes (Westend, Polkadot itself, etc). As each runtime has a
+/// specialized client, we need to hide them behind a trait. This is this trait.
+///
+/// When wanting to work with the inner client, you need to use `execute_with`.
+///
+/// See [`ExecuteWithClient`](trait.ExecuteWithClient.html) for more information.
+pub trait ClientHandle {
+	/// Execute the given something with the client.
+	fn execute_with<T: ExecuteWithClient>(&self, t: T) -> T::Output;
+}
+
+/// A client instance of Polkadot.
+///
+/// See [`ExecuteWithClient`] for more information.
+#[derive(Clone)]
+pub enum Client {
+	Polkadot(Arc<crate::FullClient<polkadot_runtime::RuntimeApi, crate::PolkadotExecutor>>),
+	Westend(Arc<crate::FullClient<westend_runtime::RuntimeApi, crate::WestendExecutor>>),
+	Kusama(Arc<crate::FullClient<kusama_runtime::RuntimeApi, crate::KusamaExecutor>>),
+}
+
+impl ClientHandle for Client {
+	fn execute_with<T: ExecuteWithClient>(&self, t: T) -> T::Output {
+		match self {
+			Self::Polkadot(client) => {
+				T::execute_with_client::<_, _, crate::FullBackend>(t, client.clone())
+			},
+			Self::Westend(client) => {
+				T::execute_with_client::<_, _, crate::FullBackend>(t, client.clone())
+			},
+			Self::Kusama(client) => {
+				T::execute_with_client::<_, _, crate::FullBackend>(t, client.clone())
+			},
+		}
+	}
+}
+
+impl sc_client_api::UsageProvider<Block> for Client {
+	fn usage_info(&self) -> sc_client_api::ClientInfo<Block> {
+		match self {
+			Self::Polkadot(client) => client.usage_info(),
+			Self::Westend(client) => client.usage_info(),
+			Self::Kusama(client) => client.usage_info(),
+		}
+	}
+}
+
+impl sc_client_api::BlockBackend<Block> for Client {
+	fn block_body(
+		&self,
+		id: &BlockId<Block>
+	) -> sp_blockchain::Result<Option<Vec<<Block as BlockT>::Extrinsic>>> {
+		match self {
+			Self::Polkadot(client) => client.block_body(id),
+			Self::Westend(client) => client.block_body(id),
+			Self::Kusama(client) => client.block_body(id),
+		}
+	}
+
+	fn block(&self, id: &BlockId<Block>) -> sp_blockchain::Result<Option<SignedBlock<Block>>> {
+		match self {
+			Self::Polkadot(client) => client.block(id),
+			Self::Westend(client) => client.block(id),
+			Self::Kusama(client) => client.block(id),
+		}
+	}
+
+	fn block_status(&self, id: &BlockId<Block>) -> sp_blockchain::Result<BlockStatus> {
+		match self {
+			Self::Polkadot(client) => client.block_status(id),
+			Self::Westend(client) => client.block_status(id),
+			Self::Kusama(client) => client.block_status(id),
+		}
+	}
+
+	fn justification(
+		&self,
+		id: &BlockId<Block>
+	) -> sp_blockchain::Result<Option<Justification>> {
+		match self {
+			Self::Polkadot(client) => client.justification(id),
+			Self::Westend(client) => client.justification(id),
+			Self::Kusama(client) => client.justification(id),
+		}
+	}
+
+	fn block_hash(
+		&self,
+		number: NumberFor<Block>
+	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
+		match self {
+			Self::Polkadot(client) => client.block_hash(number),
+			Self::Westend(client) => client.block_hash(number),
+			Self::Kusama(client) => client.block_hash(number),
+		}
+	}
+}
+
+impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
+	fn storage(
+		&self,
+		id: &BlockId<Block>,
+		key: &StorageKey,
+	) -> sp_blockchain::Result<Option<StorageData>> {
+		match self {
+			Self::Polkadot(client) => client.storage(id, key),
+			Self::Westend(client) => client.storage(id, key),
+			Self::Kusama(client) => client.storage(id, key),
+		}
+	}
+
+	fn storage_keys(
+		&self,
+		id: &BlockId<Block>,
+		key_prefix: &StorageKey,
+	) -> sp_blockchain::Result<Vec<StorageKey>> {
+		match self {
+			Self::Polkadot(client) => client.storage_keys(id, key_prefix),
+			Self::Westend(client) => client.storage_keys(id, key_prefix),
+			Self::Kusama(client) => client.storage_keys(id, key_prefix),
+		}
+	}
+
+	fn storage_hash(
+		&self,
+		id: &BlockId<Block>,
+		key: &StorageKey,
+	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
+		match self {
+			Self::Polkadot(client) => client.storage_hash(id, key),
+			Self::Westend(client) => client.storage_hash(id, key),
+			Self::Kusama(client) => client.storage_hash(id, key),
+		}
+	}
+
+	fn storage_pairs(
+		&self,
+		id: &BlockId<Block>,
+		key_prefix: &StorageKey,
+	) -> sp_blockchain::Result<Vec<(StorageKey, StorageData)>> {
+		match self {
+			Self::Polkadot(client) => client.storage_pairs(id, key_prefix),
+			Self::Westend(client) => client.storage_pairs(id, key_prefix),
+			Self::Kusama(client) => client.storage_pairs(id, key_prefix),
+		}
+	}
+
+	fn storage_keys_iter<'a>(
+		&self,
+		id: &BlockId<Block>,
+		prefix: Option<&'a StorageKey>,
+		start_key: Option<&StorageKey>,
+	) -> sp_blockchain::Result<KeyIterator<'a, <crate::FullBackend as sc_client_api::Backend<Block>>::State, Block>> {
+		match self {
+			Self::Polkadot(client) => client.storage_keys_iter(id, prefix, start_key),
+			Self::Westend(client) => client.storage_keys_iter(id, prefix, start_key),
+			Self::Kusama(client) => client.storage_keys_iter(id, prefix, start_key),
+		}
+	}
+
+	fn child_storage(
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key: &StorageKey,
+	) -> sp_blockchain::Result<Option<StorageData>> {
+		match self {
+			Self::Polkadot(client) => client.child_storage(id, child_info, key),
+			Self::Westend(client) => client.child_storage(id, child_info, key),
+			Self::Kusama(client) => client.child_storage(id, child_info, key),
+		}
+	}
+
+	fn child_storage_keys(
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key_prefix: &StorageKey,
+	) -> sp_blockchain::Result<Vec<StorageKey>> {
+		match self {
+			Self::Polkadot(client) => client.child_storage_keys(id, child_info, key_prefix),
+			Self::Westend(client) => client.child_storage_keys(id, child_info, key_prefix),
+			Self::Kusama(client) => client.child_storage_keys(id, child_info, key_prefix),
+		}
+	}
+
+	fn child_storage_hash(
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key: &StorageKey,
+	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
+		match self {
+			Self::Polkadot(client) => client.child_storage_hash(id, child_info, key),
+			Self::Westend(client) => client.child_storage_hash(id, child_info, key),
+			Self::Kusama(client) => client.child_storage_hash(id, child_info, key),
+		}
+	}
+
+	fn max_key_changes_range(
+		&self,
+		first: NumberFor<Block>,
+		last: BlockId<Block>,
+	) -> sp_blockchain::Result<Option<(NumberFor<Block>, BlockId<Block>)>> {
+		match self {
+			Self::Polkadot(client) => client.max_key_changes_range(first, last),
+			Self::Westend(client) => client.max_key_changes_range(first, last),
+			Self::Kusama(client) => client.max_key_changes_range(first, last),
+		}
+	}
+
+	fn key_changes(
+		&self,
+		first: NumberFor<Block>,
+		last: BlockId<Block>,
+		storage_key: Option<&PrefixedStorageKey>,
+		key: &StorageKey,
+	) -> sp_blockchain::Result<Vec<(NumberFor<Block>, u32)>> {
+		match self {
+			Self::Polkadot(client) => client.key_changes(first, last, storage_key, key),
+			Self::Westend(client) => client.key_changes(first, last, storage_key, key),
+			Self::Kusama(client) => client.key_changes(first, last, storage_key, key),
+		}
+	}
+}
diff --git a/node/service/src/lib.rs b/node/service/src/lib.rs
index c8295c29c55c..0377746608ca 100644
--- a/node/service/src/lib.rs
+++ b/node/service/src/lib.rs
@@ -22,13 +22,12 @@ mod client;
 
 use std::sync::Arc;
 use std::time::Duration;
-use polkadot_primitives::v1::{AccountId, Nonce, Balance};
-use service::{error::Error as ServiceError};
+use service::{error::Error as ServiceError, RpcHandlers};
 use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider};
 use sc_executor::native_executor_instance;
 use log::info;
 use sp_blockchain::HeaderBackend;
-use polkadot_overseer::{self as overseer, AllSubsystems, BlockInfo, Overseer, OverseerHandler};
+use polkadot_overseer::{AllSubsystems, BlockInfo, Overseer, OverseerHandler};
 use polkadot_subsystem::DummySubsystem;
 use polkadot_node_core_proposer::ProposerFactory;
 use sp_trie::PrefixedMemoryDB;
@@ -55,7 +54,7 @@ pub use polkadot_runtime;
 pub use kusama_runtime;
 pub use westend_runtime;
 use prometheus_endpoint::Registry;
-pub use self::client::PolkadotClient;
+pub use self::client::{AbstractClient, Client, RuntimeApiCollection};
 
 native_executor_instance!(
 	pub PolkadotExecutor,
@@ -78,40 +77,6 @@ native_executor_instance!(
 	frame_benchmarking::benchmarking::HostFunctions,
 );
 
-/// A set of APIs that polkadot-like runtimes must implement.
-pub trait RuntimeApiCollection:
-	sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>
-	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
-	+ babe_primitives::BabeApi<Block>
-	+ grandpa_primitives::GrandpaApi<Block>
-	+ sp_block_builder::BlockBuilder<Block>
-	+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
-	+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
-	+ sp_api::Metadata<Block>
-	+ sp_offchain::OffchainWorkerApi<Block>
-	+ sp_session::SessionKeys<Block>
-	+ authority_discovery_primitives::AuthorityDiscoveryApi<Block>
-where
-	<Self as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<HashFor<Block>>,
-{}
-
-impl<Api> RuntimeApiCollection for Api
-where
-	Api:
-	sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>
-	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
-	+ babe_primitives::BabeApi<Block>
-	+ grandpa_primitives::GrandpaApi<Block>
-	+ sp_block_builder::BlockBuilder<Block>
-	+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
-	+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
-	+ sp_api::Metadata<Block>
-	+ sp_offchain::OffchainWorkerApi<Block>
-	+ sp_session::SessionKeys<Block>
-	+ authority_discovery_primitives::AuthorityDiscoveryApi<Block>,
-	<Self as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<HashFor<Block>>,
-{}
-
 /// Can be called for a `Configuration` to check if it is a configuration for the `Kusama` network.
 pub trait IdentifyVariant {
 	/// Returns if this is a configuration for the `Kusama` network.
@@ -313,13 +278,14 @@ fn real_overseer<S: SpawnNamed>(
 fn new_full<RuntimeApi, Executor>(
 	mut config: Configuration,
 	collating_for: Option<(CollatorId, ParaId)>,
-	_max_block_data_size: Option<u64>,
-	_authority_discovery_enabled: bool,
-	_slot_duration: u64,
+	authority_discovery_enabled: bool,
 	grandpa_pause: Option<(u32, u32)>,
 ) -> Result<(
 	TaskManager,
 	Arc<FullClient<RuntimeApi, Executor>>,
+	Arc<sc_network::NetworkService<Block, <Block as BlockT>::Hash>>,
+	RpcHandlers,
+	OverseerHandler,
 ), Error>
 	where
 		RuntimeApi: ConstructRuntimeApi<Block, FullClient<RuntimeApi, Executor>> + Send + Sync + 'static,
@@ -337,7 +303,13 @@ fn new_full<RuntimeApi, Executor>(
 	let name = config.network.node_name.clone();
 
 	let service::PartialComponents {
-		client, backend, mut task_manager, keystore, select_chain, import_queue, transaction_pool,
+		client,
+		backend,
+		mut task_manager,
+		keystore,
+		select_chain,
+		import_queue,
+		transaction_pool,
 		inherent_data_providers,
 		other: (rpc_extensions_builder, import_setup, rpc_setup)
 	} = new_partial::<RuntimeApi, Executor>(&mut config)?;
@@ -368,7 +340,7 @@ fn new_full<RuntimeApi, Executor>(
 
 	let telemetry_connection_sinks = service::TelemetryConnectionSinks::default();
 
-	service::spawn_tasks(service::SpawnTasksParams {
+	let rpc_handlers = service::spawn_tasks(service::SpawnTasksParams {
 		config,
 		backend: backend.clone(),
 		client: client.clone(),
@@ -411,7 +383,7 @@ fn new_full<RuntimeApi, Executor>(
 	task_manager.spawn_essential_handle().spawn_blocking("overseer", Box::pin(async move {
 		use futures::{pin_mut, select, FutureExt};
 
-		let forward = overseer::forward_events(overseer_client, handler);
+		let forward = polkadot_overseer::forward_events(overseer_client, handler_clone);
 
 		let forward = forward.fuse();
 		let overseer_fut = overseer.run().fuse();
@@ -435,7 +407,7 @@ fn new_full<RuntimeApi, Executor>(
 		let proposer = ProposerFactory::new(
 			client.clone(),
 			transaction_pool,
-			handler_clone,
+			handler.clone(),
 		);
 
 		let babe_config = babe::BabeParams {
@@ -457,7 +429,7 @@ fn new_full<RuntimeApi, Executor>(
 
 	// if the node isn't actively participating in consensus then it doesn't
 	// need a keystore, regardless of which protocol we use below.
-	let keystore = if is_authority {
+	let keystore_opt = if is_authority {
 		Some(keystore.clone() as BareCryptoStorePtr)
 	} else {
 		None
@@ -469,7 +441,7 @@ fn new_full<RuntimeApi, Executor>(
 		justification_period: 512,
 		name: Some(name),
 		observer_enabled: false,
-		keystore,
+		keystore: keystore_opt,
 		is_authority: role.is_network_authority(),
 	};
 
@@ -508,7 +480,7 @@ fn new_full<RuntimeApi, Executor>(
 			inherent_data_providers: inherent_data_providers.clone(),
 			telemetry_on_connect: Some(telemetry_connection_sinks.on_connect_stream()),
 			voting_rule,
-			prometheus_registry,
+			prometheus_registry: prometheus_registry.clone(),
 			shared_voter_state,
 		};
 
@@ -524,15 +496,51 @@ fn new_full<RuntimeApi, Executor>(
 		)?;
 	}
 
+	if matches!(role, Role::Authority{..} | Role::Sentry{..}) {
+		use sc_network::Event;
+		use futures::StreamExt;
+
+		if authority_discovery_enabled {
+			let (sentries, authority_discovery_role) = match role {
+				Role::Authority { ref sentry_nodes } => (
+					sentry_nodes.clone(),
+					authority_discovery::Role::Authority (
+						keystore.clone(),
+					),
+				),
+				Role::Sentry {..} => (
+					vec![],
+					authority_discovery::Role::Sentry,
+				),
+				_ => unreachable!("Due to outer matches! constraint; qed."),
+			};
+
+			let network_event_stream = network.event_stream("authority-discovery");
+			let dht_event_stream = network_event_stream.filter_map(|e| async move { match e {
+				Event::Dht(e) => Some(e),
+				_ => None,
+			}}).boxed();
+			let (authority_discovery_worker, _service) = authority_discovery::new_worker_and_service(
+				client.clone(),
+				network.clone(),
+				sentries,
+				dht_event_stream,
+				authority_discovery_role,
+				prometheus_registry.clone(),
+			);
+
+			task_manager.spawn_handle().spawn("authority-discovery-worker", authority_discovery_worker);
+		}
+	}
+
+
 	network_starter.start_network();
 
-	Ok((task_manager, client))
+	Ok((task_manager, client, network, rpc_handlers, handler))
 }
 
-pub struct FullNodeHandles;
-
 /// Builds a new service for a light client.
-fn new_light<Runtime, Dispatch>(mut config: Configuration) -> Result<TaskManager, Error>
+fn new_light<Runtime, Dispatch>(mut config: Configuration) -> Result<(TaskManager, RpcHandlers), Error>
 	where
 		Runtime: 'static + Send + Sync + ConstructRuntimeApi<Block, LightClient<Runtime, Dispatch>>,
 		<Runtime as ConstructRuntimeApi<Block, LightClient<Runtime, Dispatch>>>::RuntimeApi:
@@ -617,19 +625,25 @@ fn new_light<Runtime, Dispatch>(mut config: Configuration) -> Result<TaskManager
 
 	let rpc_extensions = polkadot_rpc::create_light(light_deps);
 
-	service::spawn_tasks(service::SpawnTasksParams {
+	let rpc_handlers = service::spawn_tasks(service::SpawnTasksParams {
 		on_demand: Some(on_demand),
 		remote_blockchain: Some(backend.remote_blockchain()),
 		rpc_extensions_builder: Box::new(service::NoopRpcExtensionBuilder(rpc_extensions)),
 		task_manager: &mut task_manager,
 		telemetry_connection_sinks: service::TelemetryConnectionSinks::default(),
-		config, keystore, backend, transaction_pool, client, network, network_status_sinks,
+		config,
+		keystore,
+		backend,
+		transaction_pool,
+		client,
+		network,
+		network_status_sinks,
 		system_rpc_tx,
 	})?;
 
 	network_starter.start_network();
 
-	Ok(task_manager)
+	Ok((task_manager, rpc_handlers))
 }
 
 /// Builds a new object suitable for chain operations.
@@ -655,116 +669,44 @@ where
 	Ok((client, backend, import_queue, task_manager))
 }
 
-/// Create a new Polkadot service for a full node.
-#[cfg(feature = "full-node")]
-pub fn polkadot_new_full(
-	config: Configuration,
-	collating_for: Option<(CollatorId, ParaId)>,
-	max_block_data_size: Option<u64>,
-	authority_discovery_enabled: bool,
-	slot_duration: u64,
-	grandpa_pause: Option<(u32, u32)>,
-)
-	-> Result<(
-		TaskManager,
-		Arc<impl PolkadotClient<
-			Block,
-			FullBackend,
-			polkadot_runtime::RuntimeApi
-		>>,
-		FullNodeHandles,
-	), ServiceError>
-{
-	let (components, client) = new_full::<polkadot_runtime::RuntimeApi, PolkadotExecutor>(
-		config,
-		collating_for,
-		max_block_data_size,
-		authority_discovery_enabled,
-		slot_duration,
-		grandpa_pause,
-	)?;
-
-	Ok((components, client, FullNodeHandles))
-}
-
-/// Create a new Kusama service for a full node.
-#[cfg(feature = "full-node")]
-pub fn kusama_new_full(
-	config: Configuration,
-	collating_for: Option<(CollatorId, ParaId)>,
-	max_block_data_size: Option<u64>,
-	authority_discovery_enabled: bool,
-	slot_duration: u64,
-	grandpa_pause: Option<(u32, u32)>,
-) -> Result<(
-		TaskManager,
-		Arc<impl PolkadotClient<
-			Block,
-			FullBackend,
-			kusama_runtime::RuntimeApi
-			>
-		>,
-		FullNodeHandles,
-	), ServiceError>
-{
-	let (components, client) = new_full::<kusama_runtime::RuntimeApi, KusamaExecutor>(
-		config,
-		collating_for,
-		max_block_data_size,
-		authority_discovery_enabled,
-		slot_duration,
-		grandpa_pause,
-	)?;
-
-	Ok((components, client, FullNodeHandles))
+/// Build a new light node.
+pub fn build_light(config: Configuration) -> Result<(TaskManager, RpcHandlers), ServiceError> {
+	if config.chain_spec.is_kusama() {
+		new_light::<kusama_runtime::RuntimeApi, KusamaExecutor>(config)
+	} else if config.chain_spec.is_westend() {
+		new_light::<westend_runtime::RuntimeApi, WestendExecutor>(config)
+	} else {
+		new_light::<polkadot_runtime::RuntimeApi, PolkadotExecutor>(config)
+	}
 }
 
-/// Create a new Kusama service for a full node.
 #[cfg(feature = "full-node")]
-pub fn westend_new_full(
+pub fn build_full(
 	config: Configuration,
 	collating_for: Option<(CollatorId, ParaId)>,
-	max_block_data_size: Option<u64>,
 	authority_discovery_enabled: bool,
-	slot_duration: u64,
 	grandpa_pause: Option<(u32, u32)>,
-)
-	-> Result<(
-		TaskManager,
-		Arc<impl PolkadotClient<
-			Block,
-			FullBackend,
-			westend_runtime::RuntimeApi
-		>>,
-		FullNodeHandles,
-	), ServiceError>
-{
-	let (components, client) = new_full::<westend_runtime::RuntimeApi, WestendExecutor>(
-		config,
-		collating_for,
-		max_block_data_size,
-		authority_discovery_enabled,
-		slot_duration,
-		grandpa_pause,
-	)?;
-
-	Ok((components, client, FullNodeHandles))
-}
-
-/// Create a new Polkadot service for a light client.
-pub fn polkadot_new_light(config: Configuration) -> Result<TaskManager, ServiceError>
-{
-	new_light::<polkadot_runtime::RuntimeApi, PolkadotExecutor>(config)
-}
-
-/// Create a new Kusama service for a light client.
-pub fn kusama_new_light(config: Configuration) -> Result<TaskManager, ServiceError>
-{
-	new_light::<kusama_runtime::RuntimeApi, KusamaExecutor>(config)
-}
-
-/// Create a new Westend service for a light client.
-pub fn westend_new_light(config: Configuration, ) -> Result<TaskManager, ServiceError>
-{
-	new_light::<westend_runtime::RuntimeApi, KusamaExecutor>(config)
+) -> Result<(TaskManager, Client, OverseerHandler), ServiceError> {
+	if config.chain_spec.is_kusama() {
+		new_full::<kusama_runtime::RuntimeApi, KusamaExecutor>(
+			config,
+			collating_for,
+			authority_discovery_enabled,
+			grandpa_pause,
+		).map(|(task_manager, client, _, _, handler)| (task_manager, Client::Kusama(client), handler))
+	} else if config.chain_spec.is_westend() {
+		new_full::<westend_runtime::RuntimeApi, WestendExecutor>(
+			config,
+			collating_for,
+			authority_discovery_enabled,
+			grandpa_pause,
+		).map(|(task_manager, client, _, _, handler)| (task_manager, Client::Westend(client), handler))
+	} else {
+		new_full::<polkadot_runtime::RuntimeApi, PolkadotExecutor>(
+			config,
+			collating_for,
+			authority_discovery_enabled,
+			grandpa_pause,
+		).map(|(task_manager, client, _, _, handler)| (task_manager, Client::Polkadot(client), handler))
+	}
 }
diff --git a/parachain/Cargo.toml b/parachain/Cargo.toml
index 73d7f4bad5f2..027dad3539ef 100644
--- a/parachain/Cargo.toml
+++ b/parachain/Cargo.toml
@@ -10,7 +10,8 @@ edition = "2018"
 # this crate for WASM. This is critical to avoid forcing all parachain WASM into implementing
 # various unnecessary Substrate-specific endpoints.
 codec = { package = "parity-scale-codec", version = "1.3.4", default-features = false, features = [ "derive" ] }
-sp-std = { package = "sp-std", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-wasm-interface = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 polkadot-core-primitives = { path = "../core-primitives", default-features = false }
@@ -36,6 +37,7 @@ std = [
 	"derive_more",
 	"serde/std",
 	"sp-std/std",
+	"sp-runtime/std",
 	"shared_memory",
 	"sp-core/std",
 	"parking_lot",
diff --git a/runtime/kusama/src/lib.rs b/runtime/kusama/src/lib.rs
index d853a57439ff..12a1798b4f34 100644
--- a/runtime/kusama/src/lib.rs
+++ b/runtime/kusama/src/lib.rs
@@ -24,9 +24,10 @@ use sp_std::prelude::*;
 use sp_core::u32_trait::{_1, _2, _3, _4, _5};
 use codec::{Encode, Decode};
 use primitives::v1::{
-	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment,
+	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment, ValidatorId,
+	ValidatorIndex, CoreState, Id, CandidateEvent, ValidationData, OccupiedCoreAssumption,
+	CommittedCandidateReceipt, PersistedValidationData, GroupRotationInfo, ValidationCode,
 };
-use primitives::v0 as p_v0;
 use runtime_common::{
 	dummy, claims, SlowAdjustingFeeUpdate,
 	impls::{CurrencyToVoteHandler, ToAuthor},
@@ -1046,54 +1047,42 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 
-	// Dummy implementation to continue supporting old parachains runtime temporarily.
-	impl p_v0::ParachainHost<Block> for Runtime {
-		fn validators() -> Vec<p_v0::ValidatorId> {
-			// this is a compile-time check of size equality. note that we don't invoke
-			// the function and nothing here is unsafe.
-			let _ = core::mem::transmute::<p_v0::ValidatorId, AccountId>;
-
-			// Yes, these aren't actually the parachain session keys.
-			// It doesn't matter, but we shouldn't return a zero-sized vector here.
-			// As there are no parachains
-			Session::validators()
-				.into_iter()
-				.map(|k| k.using_encoded(|s| Decode::decode(&mut &s[..]))
-					.expect("correct size and raw-bytes; qed"))
-				.collect()
+	impl primitives::v1::ParachainHost<Block, Hash, BlockNumber> for Runtime {
+		fn validators() -> Vec<ValidatorId> {
+			Vec::new()
 		}
-		fn duty_roster() -> p_v0::DutyRoster {
-			let v = Session::validators();
-			p_v0::DutyRoster { validator_duty: (0..v.len()).map(|_| p_v0::Chain::Relay).collect() }
+
+		fn validator_groups() -> (Vec<Vec<ValidatorIndex>>, GroupRotationInfo<BlockNumber>) {
+			(Vec::new(), GroupRotationInfo { session_start_block: 0, group_rotation_frequency: 0, now: 0 })
 		}
-		fn active_parachains() -> Vec<(p_v0::Id, Option<(p_v0::CollatorId, p_v0::Retriable)>)> {
+
+		fn availability_cores() -> Vec<CoreState<BlockNumber>> {
 			Vec::new()
 		}
-		fn global_validation_data() -> p_v0::GlobalValidationData {
-			p_v0::GlobalValidationData {
-				max_code_size: 1,
-				max_head_data_size: 1,
-				block_number: System::block_number().saturating_sub(1),
-			}
-		}
-		fn local_validation_data(_id: p_v0::Id) -> Option<p_v0::LocalValidationData> {
+
+		fn full_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<ValidationData<BlockNumber>> {
 			None
 		}
-		fn parachain_code(_id: p_v0::Id) -> Option<p_v0::ValidationCode> {
+
+		fn persisted_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<PersistedValidationData<BlockNumber>> {
 			None
 		}
-		fn get_heads(_extrinsics: Vec<<Block as BlockT>::Extrinsic>)
-			-> Option<Vec<p_v0::AbridgedCandidateReceipt>>
-		{
+
+		fn session_index_for_child() -> SessionIndex {
+			0
+		}
+
+		fn validation_code(_: Id, _: OccupiedCoreAssumption) -> Option<ValidationCode> {
 			None
 		}
-		fn signing_context() -> p_v0::SigningContext {
-			p_v0::SigningContext {
-				parent_hash: System::parent_hash(),
-				session_index: Session::current_index(),
-			}
+
+		fn candidate_pending_availability(_: Id) -> Option<CommittedCandidateReceipt<Hash>> {
+			None
 		}
-		fn downward_messages(_id: p_v0::Id) -> Vec<p_v0::DownwardMessage> {
+
+		fn candidate_events() -> Vec<CandidateEvent<Hash>> {
 			Vec::new()
 		}
 	}
diff --git a/runtime/polkadot/src/lib.rs b/runtime/polkadot/src/lib.rs
index ffa3a7db9825..d7e9762ffee3 100644
--- a/runtime/polkadot/src/lib.rs
+++ b/runtime/polkadot/src/lib.rs
@@ -32,15 +32,19 @@ use sp_std::prelude::*;
 use sp_core::u32_trait::{_1, _2, _3, _4, _5};
 use codec::{Encode, Decode};
 use primitives::v1::{
-	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment,
+	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment, ValidatorId,
+	ValidatorIndex, CoreState, Id, CandidateEvent, ValidationData, OccupiedCoreAssumption,
+	CommittedCandidateReceipt, PersistedValidationData, GroupRotationInfo, ValidationCode,
+};
+use sp_runtime::{
+	create_runtime_str, generic, impl_opaque_keys, ModuleId, ApplyExtrinsicResult,
+	KeyTypeId, Percent, Permill, Perbill, curve::PiecewiseLinear,
+	transaction_validity::{TransactionValidity, TransactionSource, TransactionPriority},
+	traits::{
+		BlakeTwo256, Block as BlockT, OpaqueKeys, ConvertInto, IdentityLookup,
+		Extrinsic as ExtrinsicT, SaturatedConversion, Verify,
+	},
 };
-use primitives::v0 as p_v0;
-use sp_runtime::{create_runtime_str, generic, impl_opaque_keys, ModuleId, ApplyExtrinsicResult, KeyTypeId, Percent, Permill, Perbill, transaction_validity::{
-	TransactionValidity, TransactionSource, TransactionPriority,
-}, curve::PiecewiseLinear, traits::{
-	BlakeTwo256, Block as BlockT, OpaqueKeys, ConvertInto, IdentityLookup,
-	Extrinsic as ExtrinsicT, SaturatedConversion, Verify,
-}};
 #[cfg(feature = "runtime-benchmarks")]
 use sp_runtime::RuntimeString;
 use sp_version::RuntimeVersion;
@@ -1047,54 +1051,43 @@ sp_api::impl_runtime_apis! {
 			Executive::offchain_worker(header)
 		}
 	}
-	// Dummy implementation to continue supporting old parachains runtime temporarily.
-	impl p_v0::ParachainHost<Block> for Runtime {
-		fn validators() -> Vec<p_v0::ValidatorId> {
-			// this is a compile-time check of size equality. note that we don't invoke
-			// the function and nothing here is unsafe.
-			let _ = core::mem::transmute::<p_v0::ValidatorId, AccountId>;
-
-			// Yes, these aren't actually the parachain session keys.
-			// It doesn't matter, but we shouldn't return a zero-sized vector here.
-			// As there are no parachains
-			Session::validators()
-				.into_iter()
-				.map(|k| k.using_encoded(|s| Decode::decode(&mut &s[..]))
-					.expect("correct size and raw-bytes; qed"))
-				.collect()
+
+	impl primitives::v1::ParachainHost<Block, Hash, BlockNumber> for Runtime {
+		fn validators() -> Vec<ValidatorId> {
+			Vec::new()
 		}
-		fn duty_roster() -> p_v0::DutyRoster {
-			let v = Session::validators();
-			p_v0::DutyRoster { validator_duty: (0..v.len()).map(|_| p_v0::Chain::Relay).collect() }
+
+		fn validator_groups() -> (Vec<Vec<ValidatorIndex>>, GroupRotationInfo<BlockNumber>) {
+			(Vec::new(), GroupRotationInfo { session_start_block: 0, group_rotation_frequency: 0, now: 0 })
 		}
-		fn active_parachains() -> Vec<(p_v0::Id, Option<(p_v0::CollatorId, p_v0::Retriable)>)> {
+
+		fn availability_cores() -> Vec<CoreState<BlockNumber>> {
 			Vec::new()
 		}
-		fn global_validation_data() -> p_v0::GlobalValidationData {
-			p_v0::GlobalValidationData {
-				max_code_size: 1,
-				max_head_data_size: 1,
-				block_number: System::block_number().saturating_sub(1),
-			}
-		}
-		fn local_validation_data(_id: p_v0::Id) -> Option<p_v0::LocalValidationData> {
+
+		fn full_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<ValidationData<BlockNumber>> {
 			None
 		}
-		fn parachain_code(_id: p_v0::Id) -> Option<p_v0::ValidationCode> {
+
+		fn persisted_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<PersistedValidationData<BlockNumber>> {
 			None
 		}
-		fn get_heads(_extrinsics: Vec<<Block as BlockT>::Extrinsic>)
-			-> Option<Vec<p_v0::AbridgedCandidateReceipt>>
-		{
+
+		fn session_index_for_child() -> SessionIndex {
+			0
+		}
+
+		fn validation_code(_: Id, _: OccupiedCoreAssumption) -> Option<ValidationCode> {
 			None
 		}
-		fn signing_context() -> p_v0::SigningContext {
-			p_v0::SigningContext {
-				parent_hash: System::parent_hash(),
-				session_index: Session::current_index(),
-			}
+
+		fn candidate_pending_availability(_: Id) -> Option<CommittedCandidateReceipt<Hash>> {
+			None
 		}
-		fn downward_messages(_id: p_v0::Id) -> Vec<p_v0::DownwardMessage> {
+
+		fn candidate_events() -> Vec<CandidateEvent<Hash>> {
 			Vec::new()
 		}
 	}
diff --git a/runtime/westend/src/lib.rs b/runtime/westend/src/lib.rs
index 8093b44a1fa5..7d070bc83340 100644
--- a/runtime/westend/src/lib.rs
+++ b/runtime/westend/src/lib.rs
@@ -23,9 +23,10 @@
 use sp_std::prelude::*;
 use codec::{Encode, Decode};
 use primitives::v1::{
-	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment,
+	AccountId, AccountIndex, Balance, BlockNumber, Hash, Nonce, Signature, Moment, ValidatorId,
+	ValidatorIndex, CoreState, Id, CandidateEvent, ValidationData, OccupiedCoreAssumption,
+	CommittedCandidateReceipt, PersistedValidationData, GroupRotationInfo, ValidationCode,
 };
-use primitives::v0 as p_v0;
 use runtime_common::{
 	dummy, purchase, SlowAdjustingFeeUpdate,
 	impls::{CurrencyToVoteHandler, ToAuthor},
@@ -808,54 +809,42 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 
-	// Dummy implementation to continue supporting old parachains runtime temporarily.
-	impl p_v0::ParachainHost<Block> for Runtime {
-		fn validators() -> Vec<p_v0::ValidatorId> {
-			// this is a compile-time check of size equality. note that we don't invoke
-			// the function and nothing here is unsafe.
-			let _ = core::mem::transmute::<p_v0::ValidatorId, AccountId>;
-
-			// Yes, these aren't actually the parachain session keys.
-			// It doesn't matter, but we shouldn't return a zero-sized vector here.
-			// As there are no parachains
-			Session::validators()
-				.into_iter()
-				.map(|k| k.using_encoded(|s| Decode::decode(&mut &s[..]))
-					.expect("correct size and raw-bytes; qed"))
-				.collect()
+	impl primitives::v1::ParachainHost<Block, Hash, BlockNumber> for Runtime {
+		fn validators() -> Vec<ValidatorId> {
+			Vec::new()
 		}
-		fn duty_roster() -> p_v0::DutyRoster {
-			let v = Session::validators();
-			p_v0::DutyRoster { validator_duty: (0..v.len()).map(|_| p_v0::Chain::Relay).collect() }
+
+		fn validator_groups() -> (Vec<Vec<ValidatorIndex>>, GroupRotationInfo<BlockNumber>) {
+			(Vec::new(), GroupRotationInfo { session_start_block: 0, group_rotation_frequency: 0, now: 0 })
 		}
-		fn active_parachains() -> Vec<(p_v0::Id, Option<(p_v0::CollatorId, p_v0::Retriable)>)> {
+
+		fn availability_cores() -> Vec<CoreState<BlockNumber>> {
 			Vec::new()
 		}
-		fn global_validation_data() -> p_v0::GlobalValidationData {
-			p_v0::GlobalValidationData {
-				max_code_size: 1,
-				max_head_data_size: 1,
-				block_number: System::block_number().saturating_sub(1),
-			}
-		}
-		fn local_validation_data(_id: p_v0::Id) -> Option<p_v0::LocalValidationData> {
+
+		fn full_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<ValidationData<BlockNumber>> {
 			None
 		}
-		fn parachain_code(_id: p_v0::Id) -> Option<p_v0::ValidationCode> {
+
+		fn persisted_validation_data(_: Id, _: OccupiedCoreAssumption)
+			-> Option<PersistedValidationData<BlockNumber>> {
 			None
 		}
-		fn get_heads(_extrinsics: Vec<<Block as BlockT>::Extrinsic>)
-			-> Option<Vec<p_v0::AbridgedCandidateReceipt>>
-		{
+
+		fn session_index_for_child() -> SessionIndex {
+			0
+		}
+
+		fn validation_code(_: Id, _: OccupiedCoreAssumption) -> Option<ValidationCode> {
 			None
 		}
-		fn signing_context() -> p_v0::SigningContext {
-			p_v0::SigningContext {
-				parent_hash: System::parent_hash(),
-				session_index: Session::current_index(),
-			}
+
+		fn candidate_pending_availability(_: Id) -> Option<CommittedCandidateReceipt<Hash>> {
+			None
 		}
-		fn downward_messages(_id: p_v0::Id) -> Vec<p_v0::DownwardMessage> {
+
+		fn candidate_events() -> Vec<CandidateEvent<Hash>> {
 			Vec::new()
 		}
 	}
diff --git a/service/src/client.rs b/service/src/client.rs
index 20e924078ddf..896d922d9584 100644
--- a/service/src/client.rs
+++ b/service/src/client.rs
@@ -19,13 +19,13 @@
 use std::sync::Arc;
 use sp_api::{ProvideRuntimeApi, CallApiAt, NumberFor};
 use sp_blockchain::HeaderBackend;
-use sp_runtime::traits::{Block as BlockT, BlakeTwo256};
-use sp_runtime::generic::{BlockId, SignedBlock};
+use sp_runtime::{
+	Justification, generic::{BlockId, SignedBlock}, traits::{Block as BlockT, BlakeTwo256},
+};
 use consensus_common::BlockStatus;
-use sp_runtime::Justification;
 use sp_storage::{StorageData, StorageKey, ChildInfo, PrefixedStorageKey};
 use sc_client_api::{Backend as BackendT, BlockchainEvents, KeyIterator};
-use polkadot_primitives::v0::{Block, ParachainHost, AccountId, Nonce, Balance};
+use polkadot_primitives::v0::{Block, AccountId, Nonce, Balance};
 
 /// A set of APIs that polkadot-like runtimes must implement.
 pub trait RuntimeApiCollection:
@@ -33,7 +33,6 @@ pub trait RuntimeApiCollection:
 	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
 	+ babe_primitives::BabeApi<Block>
 	+ grandpa_primitives::GrandpaApi<Block>
-	+ ParachainHost<Block>
 	+ sp_block_builder::BlockBuilder<Block>
 	+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
 	+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
@@ -52,7 +51,6 @@ where
 	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
 	+ babe_primitives::BabeApi<Block>
 	+ grandpa_primitives::GrandpaApi<Block>
-	+ ParachainHost<Block>
 	+ sp_block_builder::BlockBuilder<Block>
 	+ frame_system_rpc_runtime_api::AccountNonceApi<Block, AccountId, Nonce>
 	+ pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<Block, Balance>
@@ -173,7 +171,7 @@ impl sc_client_api::UsageProvider<Block> for Client {
 
 impl sc_client_api::BlockBackend<Block> for Client {
 	fn block_body(
-		&self, 
+		&self,
 		id: &BlockId<Block>
 	) -> sp_blockchain::Result<Option<Vec<<Block as BlockT>::Extrinsic>>> {
 		match self {
@@ -200,7 +198,7 @@ impl sc_client_api::BlockBackend<Block> for Client {
 	}
 
 	fn justification(
-		&self, 
+		&self,
 		id: &BlockId<Block>
 	) -> sp_blockchain::Result<Option<Justification>> {
 		match self {
@@ -211,7 +209,7 @@ impl sc_client_api::BlockBackend<Block> for Client {
 	}
 
 	fn block_hash(
-		&self, 
+		&self,
 		number: NumberFor<Block>
 	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
 		match self {
@@ -224,9 +222,9 @@ impl sc_client_api::BlockBackend<Block> for Client {
 
 impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	fn storage(
-		&self, 
-		id: &BlockId<Block>, 
-		key: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		key: &StorageKey,
 	) -> sp_blockchain::Result<Option<StorageData>> {
 		match self {
 			Self::Polkadot(client) => client.storage(id, key),
@@ -236,9 +234,9 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn storage_keys(
-		&self, 
-		id: &BlockId<Block>, 
-		key_prefix: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		key_prefix: &StorageKey,
 	) -> sp_blockchain::Result<Vec<StorageKey>> {
 		match self {
 			Self::Polkadot(client) => client.storage_keys(id, key_prefix),
@@ -246,11 +244,11 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 			Self::Kusama(client) => client.storage_keys(id, key_prefix),
 		}
 	}
-	
+
 	fn storage_hash(
-		&self, 
-		id: &BlockId<Block>, 
-		key: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		key: &StorageKey,
 	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
 		match self {
 			Self::Polkadot(client) => client.storage_hash(id, key),
@@ -260,9 +258,9 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn storage_pairs(
-		&self, 
-		id: &BlockId<Block>, 
-		key_prefix: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		key_prefix: &StorageKey,
 	) -> sp_blockchain::Result<Vec<(StorageKey, StorageData)>> {
 		match self {
 			Self::Polkadot(client) => client.storage_pairs(id, key_prefix),
@@ -272,10 +270,10 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn storage_keys_iter<'a>(
-		&self, 
-		id: &BlockId<Block>, 
-		prefix: Option<&'a StorageKey>, 
-		start_key: Option<&StorageKey>
+		&self,
+		id: &BlockId<Block>,
+		prefix: Option<&'a StorageKey>,
+		start_key: Option<&StorageKey>,
 	) -> sp_blockchain::Result<KeyIterator<'a, <crate::FullBackend as sc_client_api::Backend<Block>>::State, Block>> {
 		match self {
 			Self::Polkadot(client) => client.storage_keys_iter(id, prefix, start_key),
@@ -285,10 +283,10 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn child_storage(
-		&self, 
-		id: &BlockId<Block>, 
-		child_info: &ChildInfo, 
-		key: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key: &StorageKey,
 	) -> sp_blockchain::Result<Option<StorageData>> {
 		match self {
 			Self::Polkadot(client) => client.child_storage(id, child_info, key),
@@ -298,10 +296,10 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn child_storage_keys(
-		&self, 
-		id: &BlockId<Block>, 
-		child_info: &ChildInfo, 
-		key_prefix: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key_prefix: &StorageKey,
 	) -> sp_blockchain::Result<Vec<StorageKey>> {
 		match self {
 			Self::Polkadot(client) => client.child_storage_keys(id, child_info, key_prefix),
@@ -311,10 +309,10 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn child_storage_hash(
-		&self, 
-		id: &BlockId<Block>, 
-		child_info: &ChildInfo, 
-		key: &StorageKey
+		&self,
+		id: &BlockId<Block>,
+		child_info: &ChildInfo,
+		key: &StorageKey,
 	) -> sp_blockchain::Result<Option<<Block as BlockT>::Hash>> {
 		match self {
 			Self::Polkadot(client) => client.child_storage_hash(id, child_info, key),
@@ -324,9 +322,9 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn max_key_changes_range(
-		&self, 
-		first: NumberFor<Block>, 
-		last: BlockId<Block>
+		&self,
+		first: NumberFor<Block>,
+		last: BlockId<Block>,
 	) -> sp_blockchain::Result<Option<(NumberFor<Block>, BlockId<Block>)>> {
 		match self {
 			Self::Polkadot(client) => client.max_key_changes_range(first, last),
@@ -336,11 +334,11 @@ impl sc_client_api::StorageProvider<Block, crate::FullBackend> for Client {
 	}
 
 	fn key_changes(
-		&self, 
-		first: NumberFor<Block>, 
-		last: BlockId<Block>, 
-		storage_key: Option<&PrefixedStorageKey>, 
-		key: &StorageKey
+		&self,
+		first: NumberFor<Block>,
+		last: BlockId<Block>,
+		storage_key: Option<&PrefixedStorageKey>,
+		key: &StorageKey,
 	) -> sp_blockchain::Result<Vec<(NumberFor<Block>, u32)>> {
 		match self {
 			Self::Polkadot(client) => client.key_changes(first, last, storage_key, key),