hasTransaction - Cardano

Example code for the hasTransaction WebSocket method. Complete guide on how to use hasTransaction WebSocket in GetBlock Web3 documentation.

This method reports whether a transaction with the given id is present in the acquired mempool snapshot. This protocol requires a WebSocket connection.

Parameters

Parameter	Type	Required	Description
id	string	Yes	The transaction id to look for

Request

JavaScript

example.js

import WebSocket from 'ws';

const client = new WebSocket('wss://go.getblock.io/<ACCESS-TOKEN>/');

client.once('open', () => {
    client.send(JSON.stringify({"jsonrpc": "2.0", "method": "hasTransaction", "params": {"id": "10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642"}, "id": "getblock.io"}));
});

client.on('message', (msg) => {
    console.log(JSON.parse(msg.toString()));
    client.close();
});

Python

example.py

import asyncio
import json
import websockets

async def main():
    async with websockets.connect('wss://go.getblock.io/<ACCESS-TOKEN>/') as ws:
        await ws.send(json.dumps({"jsonrpc": "2.0", "method": "hasTransaction", "params": {"id": "10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642"}, "id": "getblock.io"}))
        print(json.loads(await ws.recv()))

asyncio.run(main())

Response

{
    "jsonrpc": "2.0",
    "method": "hasTransaction",
    "result": true,
    "id": "getblock.io"
}

Response Parameters

Field	Type	Description
result	boolean	true if the transaction is in the snapshot, otherwise false

Use Cases

• Propagation Confirmation: Confirm a submitted transaction is pending

• Deduplication: Avoid resubmitting a transaction already in the mempool

• Status Tracking: Report a transaction as pending to a user

• Monitoring: Watch for a specific transaction to appear

Error Handling

Error Code	Message	Description
-32602	Invalid params	The request is malformed for the current protocol state
4000	Must acquire mempool	A snapshot must be acquired before this request
-32603	Internal error	The node failed to answer the mempool request