> 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/ethereum-eth/eth_newblockfilter-ethereum.md).

# eth\_newBlockFilter - Ethereum

This method creates a filter that fires each time a new block is added to the chain. Returns a filter ID that subsequent `eth_getFilterChanges` calls poll to receive block hashes. Lighter-weight than log filters — no criteria, just chain-tip advancement notifications.

## Parameters

This method takes no parameters.

## Request

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

```bash
curl --location --request POST 'https://go.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="Axios" %}
{% code title="example.js" %}

```javascript
const axios = require('axios');

const response = await axios.post('https://go.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'eth_newBlockFilter',
    params: [],
    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://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'eth_newBlockFilter',
        'params': [],
        '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://go.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "eth_newBlockFilter",
            "params": [],
            "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": "0x1a"
}
```

## Response Parameters

| Parameter | Type   | Description                                                                        |
| --------- | ------ | ---------------------------------------------------------------------------------- |
| `jsonrpc` | string | JSON-RPC protocol version ("2.0")                                                  |
| `id`      | string | Request identifier matching the request                                            |
| `result`  | string | Hex-encoded filter ID — pass to `eth_getFilterChanges` to receive new block hashes |

## Use Cases

* **New Block Notifications**: Poll to receive block hashes for each newly produced block without subscribing over WSS
* **Simple Chain-Progress Indicators**: Feed a UI 'live block' badge without full block details
* **Trigger Periodic Work**: Kick off backend work (indexer runs, reorg checks) once per new block

## Error Handling

| Error Code | Message        | Description                      |
| ---------- | -------------- | -------------------------------- |
| -32603     | Internal error | Node failed to create the filter |

## Web3 Integration

{% tabs %}
{% tab title="Ethers.js" %}
{% code title="ethers-example.js" overflow="wrap" %}

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

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

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

setInterval(async () => {
    const hashes = await provider.send('eth_getFilterChanges', [filterId]);
    hashes.forEach(h => console.log('New block:', h));
}, 12000);
```

{% endcode %}
{% endtab %}

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

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

const client = createPublicClient({
    chain: mainnet,
    transport: http('https://go.getblock.io/<ACCESS-TOKEN>/'),
});

const filter = await client.createBlockFilter();
console.log('Block filter ID:', filter.id);

setInterval(async () => {
    const hashes = await client.getFilterChanges({ filter });
    hashes.forEach(h => console.log('New block:', h));
}, 12000);
```

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


---

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