eth_chainId

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": []
}

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

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x2105"
}

Defined in EIP-695

Returns the currently configured chain ID, a value used in replay-protected transaction signing as introduced by EIP-155.

Parameters

This method does not accept any parameters.

string

A hexadecimal string representing the chain ID.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": []
}

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

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x2105"
}

Code	Message	Description
4100	Requested method not supported	The method is not supported by the wallet

Common chain IDs: Ethereum Mainnet (0x1), Base Mainnet (0x2105), Base Sepolia (0x14a34).