# getblockfilter - Bitcoin {disallowed}

This method retrieves a BIP 157 content filter for a particular block.

### Parameters

| Parameter  | Type   | Required | Description                                     |
| ---------- | ------ | -------- | ----------------------------------------------- |
| blockhash  | string | Yes      | The hash of the block.                          |
| filtertype | string | No       | The type name of the filter (default: "basic"). |

### Request

{% tabs %}
{% tab title="cURL" %}

```bash
curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "getblockfilter",
    "params": ["000000000000000000046b9302e08c16ea186950f42a5498320ddd1bd7ab3428", "basic"],
    "id": "getblock.io"
}'
```

{% endtab %}

{% tab title="Axios" %}

```javascript
import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "getblockfilter",
    "params": ["000000000000000000046b9302e08c16ea186950f42a5498320ddd1bd7ab3428", "basic"],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://go.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));
```

{% endtab %}

{% tab title="request" %}

```python
import requests
import json

url = "https://go.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "getblockfilter",
    "params": ["000000000000000000046b9302e08c16ea186950f42a5498320ddd1bd7ab3428", "basic"],
    "id": "getblock.io"
})

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

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

{% endtab %}

{% tab title="Rust" %}

```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://go.getblock.io/<ACCESS-TOKEN>/")
        .header(header::CONTENT_TYPE, "application/json")
        .body(r#"{
            "jsonrpc": "2.0",
            "method": "getblockfilter",
            "params": ["000000000000000000046b9302e08c16ea186950f42a5498320ddd1bd7ab3428", "basic"],
            "id": "getblock.io"
        }"#)
        .send()
        .await?;
    
    println!("{}", response.text().await?);
    Ok(())
}
```

{% endtab %}
{% endtabs %}

### Response

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "filter": "0193b2a0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6...",
        "header": "a1b2c3d4e5f6789abcdef0123456789abcdef01234567890abcdef1234567890"
    }
}
```

### Response Parameters

| Field  | Type   | Description                    |
| ------ | ------ | ------------------------------ |
| filter | string | The hex-encoded filter data.   |
| header | string | The hex-encoded filter header. |

### Use Case

The `getblockfilter` method is essential for:

* Light client implementations (BIP 157/158)
* Efficient address balance scanning
* Privacy-preserving blockchain queries
* Mobile wallet synchronization
* Reducing bandwidth for SPV clients
* Building neutrino-compatible applications

### Error Handling

| Status Code | Error Message     | Cause                                          |
| ----------- | ----------------- | ---------------------------------------------- |
| 403         | Forbidden         | Missing or invalid ACCESS-TOKEN.               |
| -5          | Block not found   | The specified block hash does not exist.       |
| -1          | Index not enabled | Block filter index is not enabled on the node. |

### Integration With Web3

The `getblockfilter` method helps developers:

* Build light wallet implementations
* Reduce bandwidth requirements for clients
* Implement BIP 157/158 protocols
* Create privacy-focused wallet scanners
* Support mobile and resource-constrained devices


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.getblock.io/api-reference/bitcoin-btc/btc_getblockfilter.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.