finalizepsbt - Bitcoin

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

This method finalizes a PSBT once all inputs are signed and, if complete, extracts the network-ready transaction. It returns the finalized PSBT or the extracted hex.

Parameters

Parameter	Type	Required	Description
psbt	string	Yes	The base64-encoded PSBT
extract	boolean	No	Whether to extract and return the raw transaction if complete (default: true)

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "finalizepsbt",
    "params": ["cHNidP8BAHUCAAAAASaBcTce3/KF6Tet7qSze3gADAVmy7OtZGQXE8pCFxv2AAAAAAD+////AtPf9QUAAAAAGXapFPUKlXhpm/rZ4JBKZ2n3nQ4jCMYBiKz1AAAAAA=="],
    "id": "getblock.io"
}'

bitcoinjs-lib

example.js

const axios = require('axios');

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'finalizepsbt',
    params: ["cHNidP8BAHUCAAAAASaBcTce3/KF6Tet7qSze3gADAVmy7OtZGQXE8pCFxv2AAAAAAD+////AtPf9QUAAAAAGXapFPUKlXhpm/rZ4JBKZ2n3nQ4jCMYBiKz1AAAAAA=="],
    id: 'getblock.io'
}, {
    headers: { 'Content-Type': 'application/json' }
});

console.log(response.data.result);

Request

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'finalizepsbt',
        'params': ["cHNidP8BAHUCAAAAASaBcTce3/KF6Tet7qSze3gADAVmy7OtZGQXE8pCFxv2AAAAAAD+////AtPf9QUAAAAAGXapFPUKlXhpm/rZ4JBKZ2n3nQ4jCMYBiKz1AAAAAA=="],
        'id': 'getblock.io'
    }
)

print(response.json())

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://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "finalizepsbt",
            "params": ["cHNidP8BAHUCAAAAASaBcTce3/KF6Tet7qSze3gADAVmy7OtZGQXE8pCFxv2AAAAAAD+////AtPf9QUAAAAAGXapFPUKlXhpm/rZ4JBKZ2n3nQ4jCMYBiKz1AAAAAA=="],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

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

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "hex": "0200000001a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8091a2b3c4d5e6f708192a3b4c5d60000000000ffffffff0100e1f505000000001600141d0f172a0ecb48aee1be1f2687d2963ae33f71a100000000",
        "complete": true
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	object	Object with the finalized PSBT or extracted transaction

Result Object

Field	Type	Description
psbt	string	The finalized PSBT, when not extracting
hex	string	The extracted network-ready transaction, when complete
complete	boolean	Whether the transaction is fully signed and finalized

Use Cases

• Transaction Extraction: Produce a broadcastable transaction from a PSBT

• Signing Completion: Finalize once all signatures are present

• Custody: Extract from a fully signed PSBT

• Automation: Finalize and broadcast in a pipeline

Error Handling

Error Code	Message	Description
403	Forbidden	Missing or invalid ACCESS-TOKEN
-22	Decode failed	The transaction or script could not be decoded
-8	Invalid parameter	A parameter is out of range or malformed
-32602	Invalid params	A parameter is missing or has the wrong type