I think this is a fine proposal, with some definite benefit, but I think it leaves some user experience to be desired.
Part of the reason this EIP is needed is because currently the EIP-3085 wallet_addEthereumChain method will throw an error when trying to switch the user to a “default” network on MetaMask, and so there is currently no programmatic way to suggest a user switch to a “default” network.
One proposed approach is this EIP as well as a hasEthereumChain method, which combined would mean potentially multiple acts of consent to perform this one action:
- Permission to view available networks
- (if the network is not available) Permission to add & switch to network
- (if the network is available) Permission to switch network
Meanwhile, the dapp didn’t need to view all networks to complete its intended goal of suggesting a network if it wasn’t present. It could’ve provided that fallback case in its original request.
I think these many actions can be summarized with a single method instead, like a switchWithOptionalFallbackToAdd method. The current proposal could be simply extended with an optional parameter to make this possible.
For example, we could provide an optional parameter fallbackRpc, which if the user lacked the requested network would fall back to triggering the EIP-3085: wallet_addEthereumChain logic.
{
"id": 1,
"jsonrpc": "2.0",
"method": "wallet_switchEthereumChain",
"params": [
{
"chainId": "0x5",
"fallbackRpc": {
"chainId": "0x5",
"chainName": "Goerli",
"rpcUrl": "https://goerli.infura.io/v3/INSERT_API_KEY_HERE",
"nativeCurrency": {
"name": "Goerli ETH",
"symbol": "gorETH",
"decimals": 18
},
"blockExplorerUrl": "https://goerli.etherscan.io"
}
}
]
}