> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/bitcoin-btc/bitcoin-btc-json-rpc-api/analyzepsbt-bitcoin.md).

# 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

{% tabs %}
{% tab title="cURL" %}
{% code overflow="wrap" %}

```bash
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"
}'
```

{% endcode %}
{% endtab %}

{% tab title="bitcoinjs-lib" %}
{% code title="example.js" overflow="wrap" %}

```javascript
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);
```

{% endcode %}
{% endtab %}

{% tab title="Request" %}
{% code title="example.py" %}

```python
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())
```

{% endcode %}
{% endtab %}

{% tab title="Rust" %}
{% code title="example.rs" %}

```rust
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(())
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

## Response

```json
{
    "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   |