> 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/tempo/eth_subscribe-tempo.md).

# eth\_subscribe - Tempo

Creates a real-time subscription over a WebSocket connection. Available subscription types are `newHeads` (new block headers), `logs` (matching contract events), and `newPendingTransactions` (mempool). Only available over WebSocket transport — use `wss://go.getblock.io/<ACCESS-TOKEN>/`.

{% hint style="info" %}
**WebSocket-only method.** Available only over the WebSocket transport at `wss://go.getblock.io/<ACCESS-TOKEN>/`. Calling it over HTTP POST returns an `Invalid Request` error.
{% endhint %}

## Parameters

| Parameter        | Type   | Required | Description                                               |
| ---------------- | ------ | -------- | --------------------------------------------------------- |
| subscriptionType | string | Yes      | One of `"newHeads"`, `"logs"`, `"newPendingTransactions"` |
| filterObject     | object | No       | For `"logs"`: filter with `address` and/or `topics`       |

## Request Example

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

```bash
# WebSocket-only method. Use wscat (or similar) to connect first:
wscat -c 'wss://go.getblock.io/<ACCESS-TOKEN>/'

# Then send:
{"jsonrpc": "2.0", "method": "eth_subscribe", "params": ["newHeads"], "id": "getblock.io"}
```

{% endtab %}

{% tab title="JavaScript (Axios)" %}

```javascript
import WebSocket from 'ws';

const ws = new WebSocket('wss://go.getblock.io/<ACCESS-TOKEN>/');

ws.on('open', () => {
    ws.send(JSON.stringify({
    "jsonrpc": "2.0",
    "method": "eth_subscribe",
    "params": [
        "newHeads"
    ],
    "id": "getblock.io"
}));
});

ws.on('message', (data) => {
    console.log(JSON.parse(data.toString()));
});
```

{% endtab %}

{% tab title="Python (Requests)" %}

```python
import asyncio
import json
import websockets

async def main():
    async with websockets.connect('wss://go.getblock.io/<ACCESS-TOKEN>/') as ws:
        await ws.send(json.dumps({
    "jsonrpc": "2.0",
    "method": "eth_subscribe",
    "params": [
        "newHeads"
    ],
    "id": "getblock.io"
}))
        async for message in ws:
            print(json.loads(message))

asyncio.run(main())
```

{% endtab %}

{% tab title="Rust (Reqwest)" %}

```rust
use tokio_tungstenite::connect_async;
use tokio_tungstenite::tungstenite::Message;
use serde_json::json;
use futures_util::{SinkExt, StreamExt};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let (mut ws_stream, _) = connect_async("wss://go.getblock.io/<ACCESS-TOKEN>/").await?;

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "eth_subscribe",
        "params": [
                "newHeads"
        ],
        "id": "getblock.io"
});
    ws_stream.send(Message::Text(payload.to_string())).await?;

    while let Some(msg) = ws_stream.next().await {
        println!("{:?}", msg?);
    }
    Ok(())
}
```

{% endtab %}
{% endtabs %}

## Response Example

{% code overflow="wrap" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x9cef478923ff08bf67fde6c64013158d"
}
```

{% endcode %}

## Response Parameters

| Field  | Type   | Description                                                                                            |
| ------ | ------ | ------------------------------------------------------------------------------------------------------ |
| result | string | Subscription ID, used to match incoming `eth_subscription` notifications and to call `eth_unsubscribe` |

## Use Cases

* Real-time payment notifications for merchant integrations
* Live TIP-20 transfer feeds for wallets
* Streaming indexers that react to new Tempo blocks instantly

## Error Handling

| Status Code | Error Message     | Cause                                                                    |
| ----------- | ----------------- | ------------------------------------------------------------------------ |
| 403         | Forbidden         | Missing or invalid `<ACCESS-TOKEN>`                                      |
| -32602      | Invalid params    | Request parameters are missing or malformed                              |
| 429         | Too Many Requests | Rate limit exceeded for your plan                                        |
| -32600      | Invalid Request   | `eth_subscribe` was called over HTTP; use a WebSocket connection instead |

## SDK Integration

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

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

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

const result = await provider.send('eth_subscribe', ["newHeads"]);
console.log(result);
```

{% endtab %}

{% tab title="Viem" %}

```javascript
import { createPublicClient, http, defineChain } from 'viem';

// Tempo is not yet in viem/chains as a built-in — define it inline.
const tempo = defineChain({
    id: 4217,
    name: 'Tempo',
    network: 'tempo',
    // Tempo has no native gas token. The `nativeCurrency` field is required by viem's
    // type system; values shown here are a no-op placeholder — actual fees are paid in TIP-20.
    nativeCurrency: { name: 'USD Placeholder', symbol: 'USD', decimals: 18 },
    rpcUrls: {
        default: { http: ['https://go.getblock.io/<ACCESS-TOKEN>/'] }
    },
    blockExplorers: { default: { name: 'Tempo Explorer', url: 'https://explore.tempo.xyz' } }
});

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

const result = await client.request({ method: 'eth_subscribe', params: ["newHeads"] });
console.log(result);
```

{% endtab %}
{% endtabs %}


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