author_submitAndWatchExtrinsic

author_submitAndWatchExtrinsic broadcasts a signed extrinsic and subscribes to status notifications such as Ready, InBlock, and Finalized. This is the preferred flow when your application must react immediately to zkSBT issuance, credential revocations, or shielded transfers.

ℹ️ This call requires a WebSocket transport. HTTP endpoints will return an error because they cannot keep the subscription alive.

Parameters

Parameter	Type	Required	Description
extrinsic	string	Yes	Hex-encoded, signed SCALE extrinsic.

Returns

A subscription ID. The node streams status notifications to the client until you call author_unwatchExtrinsic or the extrinsic reaches Finalized/Dropped.

WebSocket Example

import { ApiPromise, WsProvider } from '@polkadot/api';

const provider = new WsProvider('wss://api-manta-atlantic-mainnet.n.dwellir.com/YOUR_API_KEY');
const api = await ApiPromise.create({ provider });

const subscription = await api.rpc.author.submitAndWatchExtrinsic(signedExtrinsic, ({ status, events }) => {
  if (status.isReady) {
    console.log('Extrinsic queued');
  }
  if (status.isInBlock) {
    console.log('Included in block', status.asInBlock.toHex());
  }
  if (status.isFinalized) {
    console.log('Finalized in', status.asFinalized.toHex());
    events
      .filter(({ event }) => api.events.system.ExtrinsicSuccess.is(event))
      .forEach(() => console.log('✅ Execution success'));
  }
});

// Later, to stop receiving updates
await api.rpc.author.unwatchExtrinsic(subscription);

JSON-RPC Frames

// Request
{
  "jsonrpc": "2.0",
  "method": "author_submitAndWatchExtrinsic",
  "params": [
    "0x450284008eaf04151687736326c9fea17e25fc5287613693c912909cb226aa4794f26a48"
  ],
  "id": 1
}

// Example notification
{
  "jsonrpc": "2.0",
  "method": "author_extrinsicUpdate",
  "params": {
    "result": {
      "inBlock": "0x12dbd70ed24bffa8ecf8a0ac1a3ab639cdb4ce462f32fbfa33f33017dae6a604"
    },
    "subscription": "0x1"
  }
}

Operational Tips

• Use this stream when you need deterministic confirmation before issuing off-chain credentials or releasing private liquidity.
• Combine with author_pendingExtrinsics to detect if the extrinsic stalled before reaching Ready.
• Remember to unwatch long-running subscriptions to avoid WebSocket leaks.

Related Methods

• author_submitExtrinsic
• author_pendingExtrinsics
• chain_getFinalizedHead