# eth\_chainId - Ethereum

## How to Use the eth\_chainId Method

The received chain ID must fit the information in the actual known head block. It ensures that the user can apply the information for transactions’ assignment.

### **Parameters**

No parameters.

### **What you receive**

QUANTITY - large integer of the current chain id.

### Sample

Here is a typical appliance example.

#### Call

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

```bash
curl https://eth-mainnet.rpcfast.com/?api_key=<key> \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'

```

{% endtab %}
{% endtabs %}

#### Outcome

```json
{"jsonrpc":"2.0","id":1,"result":"0x1"}
```