wallet_switchEthereumChain

Request UKey Wallet to switch to the specified EVM network. If the network has not been added to your wallet yet, please add it via wallet_addEthereumChain first.

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Inputs

Pass an array whose first item is an object:

Field	Variant	Need	Remarks
chainId	string	yes	Target chain ID in 0x-prefixed hex

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return value

Returns null on success.

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Demo

try {
  await window.$ukey.ethereum.request({
    method: "wallet_switchEthereumChain",
    requestParams: [{ chainId: "0x89" }], // Note: Polygon
  });
  console.log("Changed over to Polygon");
} catch (error) {
  if (error.code === 4902) {
    // If the chain is missing, try adding it first
    await window.$ukey.ethereum.request({
      method: "wallet_addEthereumChain",
      requestParams: [
        {
          /* Note: Chain configuration */
        },
      ],
    });
  }
}

Common chain ID

chain	hexadecimal	decimal
Ethereum	0x1	1
Polygon	0x89	137
BSC	0x38	56
Arbitrum	0xa4b1	42161
Optimism	0xa	10
Base	0x2105	8453
Avalanche	0xa86a	43114

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error code

Code	Message	Details
4001	User rejected the request	Network switch was rejected by the user
4902	Chain ID is not recognized	Wallet does not have this network configured

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illustrate

• If the target chain is not configured, 4902 will be returned, and the user can be guided to add a network.
• Users may need to confirm the switch operation in their wallet.
• chainChanged will be triggered after the switch is completed, please refresh the chain-related status in the event.
• Follows EIP-3326 specification.

window.$ukey.ethereum.on("chainChanged", (chainId) => {
  console.log("Changed over to chain:", chainId);
  // Suggested action: reload the page
  window.location.reload();
});