# Eth\_chainId

## Ethereum method - eth\_chainId

> Returns the hexadecimal string of the current chain ID.

```json
{"openapi":"3.0.0","info":{"title":"Ethereum JSON-RPC","version":"1.0.0"},"servers":[{"url":"https://arbitrum.nownodes.io"}],"security":[{"api-keyAuth":[]}],"components":{"securitySchemes":{"api-keyAuth":{"type":"apiKey","in":"header","name":"api-key"}}},"paths":{"/":{"post":{"tags":["eth_chainId"],"summary":"Ethereum method - eth_chainId","description":"Returns the hexadecimal string of the current chain ID.","operationId":"ethChainId","requestBody":{"required":true,"content":{"application/json":{"schema":{"type":"object","required":["jsonrpc","method","params","id"],"properties":{"jsonrpc":{"type":"string","description":"JSON-RPC protocol version"},"method":{"type":"string","description":"Name of the method to call"},"params":{"type":"array","description":"This method does not require parameters. Use an empty array."},"id":{"type":"integer","description":"Unique identifier for the request"}}}}}},"responses":{"200":{"description":"Chain ID response","content":{"application/json":{"schema":{"type":"object","properties":{"jsonrpc":{"type":"string","description":"JSON-RPC protocol version"},"id":{"type":"integer","description":"ID matching the request"},"result":{"type":"string","description":"The chain ID in hexadecimal string format.\nFor example: \"0x1\" = Ethereum mainnet, \"0x3\" = Ropsten, \"0x5\" = Goerli, etc.\n"}}}}}}}}}}}
```