wallet_switchEthereumChain

Requests that the wallet switch to the specified chain. If the chain is not already configured in the wallet, an error will be thrown.

Parameters

Array containing a single object:

Field	Type	Required	Description
`chainId`	`string`	Yes	Chain ID (hex string with 0x prefix)

Returns

null on success

Example


try {
  await window.$onekey.ethereum.request({
    method: 'wallet_switchEthereumChain',
    params: [{ chainId: '0x89' }] // Polygon
  })
  console.log('Switched to Polygon')
} catch (error) {
  if (error.code === 4902) {
    // Chain not added, try adding it
    await window.$onekey.ethereum.request({
      method: 'wallet_addEthereumChain',
      params: [{ /* chain config */ }]
    })
  }
}

Common Chain IDs

Chain	Chain ID (Hex)	Chain ID (Decimal)
Ethereum	`0x1`	1
Polygon	`0x89`	137
BSC	`0x38`	56
Arbitrum	`0xa4b1`	42161
Optimism	`0xa`	10
Base	`0x2105`	8453
Avalanche	`0xa86a`	43114

Errors

Code	Message	Description
4001	User rejected the request	User denied the switch
4902	Unrecognized chain ID	Chain not configured in wallet

Notes

If chain is not configured, use wallet_addEthereumChain first
User may need to approve the switch
Listen to chainChanged event to detect when switch completes
Specified by EIP-3326


window.$onekey.ethereum.on('chainChanged', (chainId) => {
  console.log('Chain changed to:', chainId)
  // Recommended: reload the page
  window.location.reload()
})