optimal sign-in strategy for dapps with iOS mobile browser

[intergalacticspacehighway]

After having seen issues like #521 with iOS browser <-> wallet app redirection, I want to start a discussion of what could be the optimal sign-in strategy for dapps on iOS browser.

Sign-in steps

• Establish a connection with the wallet (assuming you'd be using WalletConnect protocol).
• On connection established, you'd ask for a personal signature so you can verify the address on the server.

Approach 1

• Show a connect button from rainbowkit.
• On connection established, get personal signature.

const { isConnected } = useConnect();

useEffect(() => {
   // Skipping some initialisation checks for simplicity
    if (isConnected) signPersonalMessage()
}, [isConnected])

Approach 2

• IMO this is better as signPersonalMessage is more like an event instead of effect.
• However, it needs a new API in rainbowkit to make an imperative call to trigger connect modal. API like this exists in web3modal.

const handleSignIn = async () => {
    const connection = await rainbowkit.connect();
    const sign = await signPersonalMessage();
}

Issues with above approaches

• iOS will redirect to web link instead of app during signPersonalMessage call.
• In the below app, we're triggering signPersonalMessage in useEffect.
• The root cause here is that iOS is not considering it to be triggered by user action and hence redirecting to the web link.

RPReplay_Final1656072509.1.MP4

TradeOff

• This one has a tradeoff where we compromise a bit on UX and show a button to trigger signature.

RPReplay_Final1656072787.1.MP4

Possible solutions

• A new API in WalletConnect protocol that can handle connect + personal signature in a single call.
• I think we can experiment with Approach 2 having an imperative API but I still think iOS won't consider it to be a user action triggered redirection.
• Compromise with UX and go with the tradeoff of showing a button to trigger signature.

Related bugs - WalletConnect/walletconnect-monorepo#1165, #522

Does anyone have any workarounds to solve this?