> 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_statenetworkversion.md).

# Filecoin.StateNetworkVersion - Filecoin

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

This method returns the Filecoin network protocol version in effect at a given tipset. The network version increments with each network upgrade.

{% hint style="info" %}
Many state methods take a tipset key as their final parameter: an array of block CIDs identifying the tipset to read. Pass an empty array `[]` to read against the current chain head.
{% endhint %}

## Parameters

| Parameter | Type  | Required | Description                                             |
| --------- | ----- | -------- | ------------------------------------------------------- |
| tipsetKey | array | Yes      | Tipset key to read from; empty array for the chain head |

## 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.StateNetworkVersion", "params": [[]], "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.StateNetworkVersion',
        params: [[]],
        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.StateNetworkVersion',
        'params': [[]],
        'id': 'getblock.io'
    }
)

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

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

## Response

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": 23
}
```

## Response Parameters

| Field  | Type    | Description                                |
| ------ | ------- | ------------------------------------------ |
| result | integer | The network protocol version at the tipset |

## Use Cases

* **Upgrade Detection**: Detect network upgrades by version
* **Compatibility**: Adapt message construction to the network version
* **Tooling**: Configure SDKs against the active version
* **Diagnostics**: Log the network version for support

## 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                      |