Module subxt::rpc

RPC types and client for interacting with a substrate node.

These is used behind the scenes by various subxt APIs, but can also be used directly.

• Rpc is the highest level wrapper, and the one you will run into first. It contains the higher level methods for interacting with a node.
• RpcClient is what Rpc uses to actually talk to a node, offering a RpcClient::request and RpcClient::subscribe method to do so.
• RpcClientT is the underlying dynamic RPC implementation. This provides the low level RpcClientT::request_raw and RpcClientT::subscribe_raw methods. This can be swapped out for a custom implementation, but by default we’ll rely on jsonrpsee for this.

Example

Fetching storage keys

use subxt::{ PolkadotConfig, OnlineClient, storage::StorageKey };

#[subxt::subxt(runtime_metadata_path = "../artifacts/polkadot_metadata.scale")]
pub mod polkadot {}

let api = OnlineClient::<PolkadotConfig>::new().await.unwrap();

let key = polkadot::storage()
    .xcm_pallet()
    .version_notifiers_root()
    .to_bytes();

// Fetch up to 10 keys.
let keys = api
    .rpc()
    .storage_keys_paged(&key, 10, None, None)
    .await
    .unwrap();

for key in keys.iter() {
    println!("Key: 0x{}", hex::encode(&key));
}

Modules

types

Types sent to/from the Substrate RPC interface.

Macros

rpc_params

Create some RpcParams to pass to our RpcClient. RpcParams simply enforces that parameters handed to our RpcClient methods are the correct shape.

Structs

RawValue

Reference to a range of bytes encompassing a single valid JSON value in the input data.

Rpc

Client for substrate rpc interfaces

RpcClient

A concrete wrapper around an RpcClientT which exposes the udnerlying interface via some higher level methods that make it a little easier to work with.

RpcParams

This represents the parameters passed to an RpcClient, and exists to enforce that parameters are provided in the correct format.

RpcSubscription

The RPC subscription returned from RpcClientT’s subscription method.

Subscription

A generic RPC Subscription. This implements Stream, and so most of the functionality you’ll need to interact with it comes from the StreamExt extension trait.

Traits

RpcClientT

Any RPC client which implements this can be used in our super::Rpc type to talk to a node.

Type Definitions

RpcFuture

A boxed future that is returned from the RpcClientT methods.

RpcSubscriptionId

The ID associated with the RpcClientT’s subscription.

RpcSubscriptionStream

The inner subscription stream returned from our RpcClientT’s subscription method.