> 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/filecoin-fil/native-api/filecoin_chaingetblockmessages.md).

# Filecoin.ChainGetBlockMessages - Filecoin

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

This method returns the messages contained in a block, split into BLS-signed and secp256k1-signed messages, along with their CIDs.

## Parameters

| Parameter | Type   | Required | Description                          |
| --------- | ------ | -------- | ------------------------------------ |
| cid       | object | Yes      | Block CID, as an object with a / key |

## 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": "Filecoin.ChainGetBlockMessages", "params": [{"/": "bafy2bzacecdkonmhngylnnhrk4azkg2wkgcm6cnm5qn5sk4ww5cszjlvkgkd6"}], "id": "getblock.io"}'
```

{% endcode %}
{% endtab %}

{% tab title="JavaScript" %}
{% code title="example.js" %}

```javascript
const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
        jsonrpc: '2.0',
        method: 'Filecoin.ChainGetBlockMessages',
        params: [{"/": "bafy2bzacecdkonmhngylnnhrk4azkg2wkgcm6cnm5qn5sk4ww5cszjlvkgkd6"}],
        id: 'getblock.io'
    })
});

const data = await response.json();
console.log(data.result);
```

{% endcode %}
{% endtab %}

{% tab title="Python" %}
{% 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': 'Filecoin.ChainGetBlockMessages',
        'params': [{"/": "bafy2bzacecdkonmhngylnnhrk4azkg2wkgcm6cnm5qn5sk4ww5cszjlvkgkd6"}],
        'id': 'getblock.io'
    }
)

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

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

## Response

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "BlsMessages": [
            {
                "Version": 0,
                "To": "f3ukhj6tpkgxjknu54opiaej2vrjz7nh7gzodkqlhpfphc6gxkogzmojv2cnlpgcuwkvnyhloctnc6lmlvceuq",
                "From": "f3ukhj6tpkgxjknu54opiaej2vrjz7nh7gzodkqlhpfphc6gxkogzmojv2cnlpgcuwkvnyhloctnc6lmlvceuq",
                "Nonce": 42,
                "Value": "1000000000000000000",
                "Method": 0
            }
        ],
        "SecpkMessages": [],
        "Cids": [
            {
                "/": "bafy2bzacea3wsdh6y3a36tb3skempjoxqpuyompjbmfeyf34fi3uy6uue42v4"
            }
        ]
    }
}
```

## Response Parameters

| Field         | Type  | Description                            |
| ------------- | ----- | -------------------------------------- |
| BlsMessages   | array | BLS-signed messages in the block       |
| SecpkMessages | array | secp256k1-signed messages in the block |
| Cids          | array | CIDs of all messages in the block      |

## Use Cases

* **Message Indexing**: Read all messages in a block
* **Transfer Tracking**: Scan a block for FIL transfers
* **Method Analysis**: Classify messages by their actor method
* **Explorers**: List a block's messages

## Error Handling

| Error Code | Message         | Description                                                 |
| ---------- | --------------- | ----------------------------------------------------------- |
| -32602     | Invalid params  | A parameter is missing or has the wrong type or format      |
| 1          | Actor not found | The address or actor does not exist in the requested tipset |
| -32603     | Internal error  | The node failed to process the request                      |