The signatureSubscribe method opens a stream that emits a single notification when a given transaction signature reaches the requested commitment level (or when transaction status changes if enableReceivedNotification is set). After the notification fires, the subscription is automatically cancelled. Pair it with signatureUnsubscribe to cancel a subscription before it fires.

Parameters

• signature: string - Transaction signature, as a base-58 encoded string.

• config (optional): object - Configuration object containing:

  • commitment: string - The commitment level. One of processed, confirmed, finalized. Defaults to finalized.
  • enableReceivedNotification: boolean (optional) - When true, the subscription also fires a notification when the transaction has been received by the node, before reaching the requested commitment.

Request

// initiate websocket stream first
wscat -c wss://solana-mainnet.g.alchemy.com/v2/<-- ALCHEMY APP API KEY -->
 
// then call subscription
{"jsonrpc":"2.0","id":1,"method":"signatureSubscribe","params":["2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b",{"commitment":"finalized","enableReceivedNotification":false}]}

import { Connection } from '@solana/web3.js'
 
const connection = new Connection(
  'https://solana-mainnet.g.alchemy.com/v2/<-- ALCHEMY APP API KEY -->',
  {
    wsEndpoint: 'wss://solana-mainnet.g.alchemy.com/v2/<-- ALCHEMY APP API KEY -->',
    commitment: 'finalized'
  }
)
 
const signature = '2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b'
 
const subscriptionId = connection.onSignature(
  signature,
  (result, context) => {
    console.log('Signature status at slot', context.slot, result)
  },
  'finalized'
)
 
// The subscription is auto-removed by the node once it fires.
// To remove it manually before it fires:
// await connection.removeSignatureListener(subscriptionId)

Result

// subscribe response
{"jsonrpc":"2.0","result":24006,"id":1}
 
// notification (commitment reached)
{
  "jsonrpc": "2.0",
  "method": "signatureNotification",
  "params": {
    "result": {
      "context": { "slot": 5207624 },
      "value": { "err": null }
    },
    "subscription": 24006
  }
}

Unsubscribe

Use signatureUnsubscribe with the subscription id returned by signatureSubscribe to cancel a pending subscription. (After the notification has already fired, the subscription is removed automatically.)

• subscription_id: number - The subscription id to cancel.

{"jsonrpc":"2.0","id":1,"method":"signatureUnsubscribe","params":[subscription_id]}

{"jsonrpc":"2.0","result":true,"id":1}

When using @solana/web3.js, call connection.removeSignatureListener(subscriptionId) instead of sending the raw JSON-RPC request.