getmempoolentry - Bitcoin Cash

Example code for the getmempoolentry JSON-RPC method. Complete guide on how to use the getmempoolentry JSON-RPC method in the GetBlock Web3 documentation.

This method returns mempool data for a single transaction that is currently in the mempool, including its fees, size, and ancestor and descendant counts.

Parameters

Parameter	Type	Required	Description
txid	string	Yes	The transaction id, which must be in the mempool

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "getmempoolentry",
    "params": ["10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642"],
    "id": "getblock.io"
}'

bitcoinjs-lib

example.js

const axios = require('axios');
const { data } = await axios.post('https://go.getblock.io/<ACCESS-TOKEN>/', {
  jsonrpc: '2.0', method: 'getmempoolentry',
  params: ['10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642'], id: 'getblock.io'
});
console.log(data.result.fees);

Request

example.py

import requests

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'getmempoolentry',
        'params': ["10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642"],
        'id': 'getblock.io'
    }
)

print(response.json()['result'])

Rust

example.rs

use reqwest::Client;
use serde_json::{json, Value};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let response = client
        .post("https://go.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "getmempoolentry",
            "params": ["10b54fd708ab2e5703979b4ba27ca0339882abc2062e77fbe51e625203a49642"],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "error": null,
    "id": "getblock.io",
    "result": {
        "size": 226,
        "time": 1617180599,
        "height": 684634,
        "descendantcount": 1,
        "descendantsize": 226,
        "ancestorcount": 1,
        "ancestorsize": 226,
        "fees": {
            "base": 2.26e-06,
            "modified": 2.26e-06,
            "ancestor": 2.26e-06,
            "descendant": 2.26e-06
        }
    }
}

Response Parameters

Parameter	Type	Description
error	null|object	Error object when the call fails, otherwise null
id	string	Request identifier matching the request
result	object	Mempool entry object for the transaction

Result Object

Field	Type	Description
size	numeric	Transaction size in bytes
time	numeric	Time the transaction entered the mempool
ancestorcount	numeric	Number of in-mempool ancestor transactions
descendantcount	numeric	Number of in-mempool descendant transactions
fees	object	Base, modified, ancestor, and descendant fees in BCH

Use Cases

• Fee Bumping: Read ancestor fees before deciding on a child-pays-for-parent spend

• Confirmation Estimates: Assess a transaction's position by its fee rate

• Chain Limits: Check ancestor and descendant counts against mempool limits

• Stuck Transactions: Diagnose why a low-fee transaction remains unconfirmed

Error Handling

Error Code	Message	Description
-8	Invalid parameter	txid is not a valid 64-character hex string
-5	Transaction not found	No transaction with the given id is available; a txindex may be required
-32603	Internal error	Node failed to read the transaction