> 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/mantle-mnt/eth_newblockfilter-mantle.md).

# eth\_newBlockFilter - Mantle

Example code for the eth\_newBlockFilter JSON-RPC method. Complete guide on how to useeth\_newBlockFilter JSON-RPC in GetBlock Web3 documentation.

This method creates a filter in the node to notify when a new block arrives. To check if the state has changed, call `eth_getFilterChanges`.

### Parameters

* None

### Request

{% tabs %}
{% tab title="curl" %}
{% code title="curl" %}

```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": "eth_newBlockFilter",
    "params": [],
    "id": "getblock.io"
}'
```

{% endcode %}
{% endtab %}

{% tab title="JavaScript (axios)" %}
{% code title="request.js" %}

```javascript
import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "eth_newBlockFilter",
    "params": [],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data)))
    .catch(error => console.log(error));
```

{% endcode %}
{% endtab %}

{% tab title="Python (requests)" %}
{% code title="request.py" %}

```python
import requests
import json

url = "https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "eth_newBlockFilter",
    "params": [],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)
```

{% endcode %}
{% endtab %}

{% tab title="Rust (reqwest)" %}
{% code title="main.rs" %}

```rust
use reqwest::header;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::new();
    
    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header(header::CONTENT_TYPE, "application/json")
        .body(r#"{
            "jsonrpc": "2.0",
            "method": "eth_newBlockFilter",
            "params": [],
            "id": "getblock.io"
        }"#)
        .send()
        .await?;
    
    println!("{}", response.text().await?);
    Ok(())
}
```

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

### Response

{% code title="response.json" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x1a2b3c4d5e6f"
}
```

{% endcode %}

### Response Parameters

| Field  | Type   | Description                                  |
| ------ | ------ | -------------------------------------------- |
| result | string | Filter ID to use with `eth_getFilterChanges` |

### Use Case

The `eth_newBlockFilter` method is essential for:

* Block monitoring without WebSocket
* New block notifications
* Chain synchronization
* Block confirmation tracking
* Backend polling services

### Error Handling

| Status Code | Error Message | Cause                           |
| ----------- | ------------- | ------------------------------- |
| 403         | Forbidden     | Missing or invalid ACCESS-TOKEN |

### Web3 Integration

{% tabs %}
{% tab title="Ethers.js" %}
{% code title="ethers.js" %}

```javascript
import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const filterId = await provider.send('eth_newBlockFilter', []);
console.log('Block Filter ID:', filterId);
```

{% endcode %}
{% endtab %}

{% tab title="Viem" %}
{% code title="viem.js" %}

```javascript
import { createPublicClient, http } from 'viem';
import { mantle } from 'viem/chains';

const client = createPublicClient({
    chain: mantle,
    transport: http('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/')
});

const filterId = await client.request({
    method: 'eth_newBlockFilter',
    params: []
});
console.log('Block Filter ID:', filterId);
```

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