Farcaster Devs

📣 We are building a simpler way to detect Mini App environment

We are considering different ways for Web apps to detect if they're running in Farcaster Mini App context vs. a regular web browser.

Which approach would you prefer as a developer? Join the discussion: https://github.com/farcasterxyz/miniapps/discussions/222

Feedback regarding detection of mini-app hosts:

• Option 1 (well-known query parameter) would be the worst because it’s another identifier apps need to hardcode and will be easily spoofed (akin to browser extension wallets setting `isMetaMask` to true on their `window.ethereum` object). Just continue to let apps specify custom params for themselves in `<meta name="fc:frame">` if they really need it.

• Option 2 (message passing) is ideal but can be improved further – I recommend turning it into a two-way message system modeled after EIP-6963 to avoid race conditions. (Also while you’re at it, use EIP-6963 to announce Farcaster Wallet’s EIP-1193 object to the app for instant compatibility with existing wallet picker UIs.)

• Option 3 (`isInMiniApp()` SDK function) – this is fine assuming apps don’t already have the SDK code-split from their main client-side bundle, but maybe redundant to Option 2.

UNBLOCK CRYPTO | EIP6963

The way web3 frontends originally interacted with the MetaMask browser extension was by looking for a global JavaScript variable at `window.ethereum` or `window.web3.currentProvider` that adheres to the EIP-1193 standard.

As more wallet browser extensions and “in-app browsers” hit the market, they copied this convention and even set the `isMetaMask` flag to `true` so that existing frontends with MetaMask buttons could find them. Hence the conflict and confusion that continues to this day 🦊⚔️🥸

The solution is to adopt EIP-6963 which uses JavaScript events instead of global variables to introduce EIP-1193 objects to the frontend.

In other words – @opensea, get your act together and support EIP-6963 already!!

EIP-6963:

https://eips.ethereum.org/EIPS/eip-6963

https://warpcast.com/darrylyeo/0xb5094494

/frontend dev (HTML/CSS)・founder/decentralized data wrangler /blockhead・contributor /ethglobal /walletbeat・hackathon bounty hunter・music maker・dropout・nomad・25

Also for Option 2, you may as well just extend the EIP-6963–announced EIP-1193 interface with custom RPC methods to avoid the need for a custom client-side SDK altogether.

https://warpcast.com/darrylyeo/0x0ac8b731

Also, Option 2 and Option 3 won’t work for detecting mini-app hosts on the server-side of the app – maybe a custom HTTP header is in order?

What’s the cost of importing and initializing `@farcaster/frame-sdk` on every page load if someone were to use my web app outside of a mini-app context? Is there an alternative flow that doesn’t rely on this dependency?

My original feedback that sparked this discussion:

My original feedback that sparked this discussion:

https://warpcast.com/darrylyeo/0x244b7782

GitHub discussion:

https://github.com/farcasterxyz/miniapps/discussions/222#discussioncomment-13054763