finalizepsbt - Bitcoin Cash

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

This method finalizes the inputs of a PSBT. If the transaction is fully signed it produces a network-ready hex; otherwise it returns the updated PSBT.

Parameters

Parameter	Type	Required	Description
psbt	string	Yes	The base64-encoded PSBT to finalize
extract	boolean	No	If true and the PSBT is complete, extract and return the network transaction. Default true

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "finalizepsbt",
    "params": ["cHNidP8BAHECAAAAAeJ+A9IdBRqivZ0zbDrAaTz6ks5xWSzuxSGxxIAZ/3ehAQAAAAD/////AqGaAQAAAAAAFgAUQiAC2SehyukB6sZoREzOjdCuYNUps7ELAAAAABepFPW0jREw3D02bR6r9ng6VS0cjgj0hwAAAAAAAAAA", true],
    "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: 'finalizepsbt',
  params: [psbt, true], id: 'getblock.io'
});
console.log(data.result.complete, data.result.hex);

Request

example.py

import requests

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'finalizepsbt',
        'params': ["cHNidP8BAHECAAAAAeJ+A9IdBRqivZ0zbDrAaTz6ks5xWSzuxSGxxIAZ/3ehAQAAAAD/////AqGaAQAAAAAAFgAUQiAC2SehyukB6sZoREzOjdCuYNUps7ELAAAAABepFPW0jREw3D02bR6r9ng6VS0cjgj0hwAAAAAAAAAA", true],
        '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": "finalizepsbt",
            "params": ["cHNidP8BAHECAAAAAeJ+A9IdBRqivZ0zbDrAaTz6ks5xWSzuxSGxxIAZ/3ehAQAAAAD/////AqGaAQAAAAAAFgAUQiAC2SehyukB6sZoREzOjdCuYNUps7ELAAAAABepFPW0jREw3D02bR6r9ng6VS0cjgj0hwAAAAAAAAAA", true],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

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

Response

{
    "error": null,
    "id": "getblock.io",
    "result": {
        "hex": "01000000000101e17e03d21d051aa2bd9d336c3ac0693cfa92ce71592ceec521b1c48019ff77a101000000171600146d76e574b5f4825fe740ba6c41aaf1b319dfb80cffffffff02819a010000000000160014422002d927a1cae901eac668444cce8dd0ae60d529b31b0b0000000017a914f5b48d1130dc3d366d1eabf6783a552d1c8e08f487000000000",
        "complete": true
    }
}

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	Object with the finalized transaction hex and completion status

Result Object

Field	Type	Description
psbt	string	The finalized PSBT, present when extract is false or signing is incomplete
hex	string	The network-ready transaction hex, present when complete
complete	boolean	Whether all inputs are finalized

Use Cases

• Broadcast Prep: Extract network-ready hex from a fully signed PSBT

• Completion Checks: Confirm all inputs are signed before broadcasting

• Multisig Finish: Finalize an m-of-n PSBT once enough signatures are gathered

• Pipeline Handoff: Produce hex for sendrawtransaction from a PSBT flow

Error Handling

Error Code	Message	Description
-22	Decode failed	The supplied data could not be decoded
-8	Invalid parameter	A required parameter is missing or malformed
-32603	Internal error	Node failed to process the request