Network

Use these standard EIP-1193 / EIP-3326 / EIP-3085 methods to read the currently connected chain, switch the user to a different one, or register a custom EVM network with StarKey.

eth_chainId

Returns the currently connected chain, as a hex string.

const chainId: string = await provider.request({ method: 'eth_chainId' })
// '0x1'

The provider also exposes this synchronously as provider.chainId once connected, without a request round-trip.

wallet_switchEthereumChain

Prompts the user to switch to a different, already-known chain.

try {
  await provider.request({
    method: 'wallet_switchEthereumChain',
    params: [{ chainId: '0x2105' }], // Base
  })
} catch (error: any) {
  if (error.code === 4902) {
    // chain not yet added to StarKey — call wallet_addEthereumChain first
  }
}

Params: [{ chainId: string }] — hex-encoded chain ID to switch to.

Returns: Promise<null> on success. Throws with code: 4902 if the chain hasn’t been added to StarKey yet — fall back to wallet_addEthereumChain in that case.

wallet_addEthereumChain

Registers a new EVM network with StarKey (and switches to it), for chains the wallet doesn’t already know about.

await provider.request({
  method: 'wallet_addEthereumChain',
  params: [
    {
      chainId: '0x279f', // Monad Testnet
      chainName: 'Monad Testnet',
      nativeCurrency: { name: 'Monad', symbol: 'MON', decimals: 18 },
      rpcUrls: ['https://testnet-rpc.monad.xyz'],
      blockExplorerUrls: ['https://testnet.monadexplorer.com'],
    },
  ],
})

Params: [AddEthereumChainParameter] — see EIP-3085  for the full field list (chainId, chainName, nativeCurrency, rpcUrls, blockExplorerUrls, iconUrls).

Returns: Promise<null> on success — StarKey switches to the new chain immediately after adding it.

Error handling

• wallet_switchEthereumChain rejects with code: 4902 for an unrecognized chain — add it first with wallet_addEthereumChain, then retry the switch.
• Both methods reject with code: 4001 if the user declines the prompt.

Notes

• Listen for the chainChanged event to react when the user switches networks from the StarKey UI directly, rather than only through your dApp’s own switch call.
• Re-read eth_accounts after a network change — StarKey may present a different active account per chain.

Best practices

• Read eth_chainId right after connecting to confirm the dApp and wallet agree on the active chain before building a transaction.
• Try wallet_switchEthereumChain first and only fall back to wallet_addEthereumChain on a 4902 error, rather than always adding the chain.

Related pages

• Establish a Connection
• Sending a Transaction
• Events