> 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/tron-trx/tron-json-rpc-api/eth_chainid-tron.md).

# eth\_chainId - Tron

This method returns the chain ID of the TRON network for JSON-RPC clients. TRON mainnet returns `0x2b6653dc` (728126428).

## Parameters

This method does not accept any parameters.

## Request

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

```bash
curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/jsonrpc' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_chainId",
    "params": [],
    "id": "getblock.io"
}'
```

{% endcode %}
{% endtab %}

{% tab title="Axios" %}
{% code title="example.js" %}

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

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/jsonrpc', {
    jsonrpc: '2.0',
    method: 'eth_chainId',
    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://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/jsonrpc',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'eth_chainId',
        '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://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/jsonrpc")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "eth_chainId",
            "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": "0x2b6653dc"
}
```

## Response Parameters

| Parameter | Type   | Description                                                    |
| --------- | ------ | -------------------------------------------------------------- |
| jsonrpc   | string | JSON-RPC protocol version ("2.0")                              |
| id        | string | Request identifier matching the request                        |
| result    | string | Hex-encoded chain ID (0x2b6653dc = 728126428 for TRON mainnet) |

## Use Cases

* **Network Detection**: Confirm a client is connected to TRON mainnet
* **Tooling Compatibility**: Provide a chain ID to Ethereum-style libraries
* **Multi-Chain Routing**: Select TRON-specific logic by chain ID
* **Endpoint Validation**: Verify an endpoint serves the expected network

## Error Handling

| Error Code | Message        | Description                                            |
| ---------- | -------------- | ------------------------------------------------------ |
| -32602     | Invalid params | A parameter is missing or has the wrong type or format |
| -32603     | Internal error | The node failed to process the request                 |