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Add a network

In some cases, such as when interacting with smart contracts, your dapp must connect a user to a new network in MetaMask. Instead of the user adding a new network manually, which requires them to configure RPC URLs and chain IDs, your dapp can use the wallet_addEthereumChain and wallet_switchEthereumChain RPC methods to prompt the user to add a specific, pre-configured network to their MetaMask wallet.

These methods are specified by EIP-3085 and EIP-3326, and we recommend using them together.

  1. wallet_addEthereumChain creates a confirmation asking the user to add the specified network to MetaMask.
  2. wallet_switchEthereumChain creates a confirmation asking the user to switch to the specified network.

The confirmations look like the following:

Add network confirmation
Switch network confirmation

Example​

The following is an example of using wallet_addEthereumChain and wallet_switchEthereumChain to prompt a user to add and switch to a new network:

try {
  await ethereum.request({
    method: 'wallet_switchEthereumChain',
    params: [{ chainId: '0xf00' }],
  });
} catch (switchError) {
  // This error code indicates that the chain has not been added to MetaMask.
  if (switchError.code === 4902) {
    try {
      await ethereum.request({
        method: 'wallet_addEthereumChain',
        params: [
          {
            chainId: '0xf00',
            chainName: '...',
            rpcUrls: ['https://...'] /* ... */,
          },
        ],
      });
    } catch (addError) {
      // handle "add" error
    }
  }
  // handle other "switch" errors
}