wallet_addEthereumChain

Add a new Ethereum chain to the wallet

Defined in EIP-3085

Requests that the wallet tracks the given chain and adds it to the wallet’s UI. This method is used to suggest new networks to the user.

Parameters

chainData · object · required

The chain data object containing network information.

Show Chain data properties

chainId · string · required

A 0x-prefixed hexadecimal string representing the chain ID.

chainName · string · required

The human-readable name of the chain.

nativeCurrency · object · required

An object describing the currency that is “native” to this chain.

Show Native currency properties

name · string · required

The name of the native currency.

symbol · string · required

The symbol of the native currency.

decimals · number · required

The number of decimals for the native currency.

rpcUrls · array · required

An array of RPC URL strings.

blockExplorerUrls · array

An array of block explorer URL strings (optional).

iconUrls · array

An array of icon URL strings (optional).

Returns

result · null

Returns null if successful.

Request

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "wallet_addEthereumChain",
  "params": [{
    "chainId": "0x2105",
    "chainName": "Base Mainnet",
    "nativeCurrency": {
      "name": "Ether",
      "symbol": "ETH",
      "decimals": 18
    },
    "rpcUrls": ["https://mainnet.base.org"],
    "blockExplorerUrls": ["https://basescan.org"]
  }]
}

Success Response

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": null
}

Error Handling

Code	Message	Description
4001	User rejected the request	User denied adding the chain
4100	Requested method not supported	The method is not supported by the wallet
4902	Unrecognized chain ID	The chain ID is not recognized

Make sure to provide accurate RPC URLs and block explorer URLs. Incorrect URLs may cause connectivity issues.