analyzepsbt - Bitcoin

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

This method analyzes a PSBT and reports what is missing for each input, the next role in the signing workflow, and the estimated fee and virtual size.

Parameters

Parameter	Type	Required	Description
psbt	string	Yes	The base64-encoded PSBT

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": "analyzepsbt",
    "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: 'analyzepsbt',
    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': 'analyzepsbt',
        '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": "analyzepsbt",
            "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": {
        "inputs": [
            {
                "has_utxo": true,
                "is_final": false,
                "missing": {
                    "signatures": [
                        "bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq"
                    ]
                },
                "next": "signer"
            }
        ],
        "estimated_vsize": 141,
        "estimated_feerate": 0.0002,
        "fee": 2.82e-05,
        "next": "signer"
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	object	PSBT analysis object

Result Object

Field	Type	Description
inputs	array	Per-input analysis with what is missing
estimated_vsize	number	Estimated virtual size once complete
estimated_feerate	number	Estimated fee rate in BTC/kvB
next	string	The next role in the workflow (updater, signer, finalizer, extractor)

Use Cases

• Workflow Routing: Determine the next signing step

• Completeness Checks: See what each input still needs

• Fee Preview: Estimate the fee before finalizing

• Wallet UX: Guide users through PSBT signing

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