How does deep linking into mini apps work?

I'd start with what you want to do in your app and work from there. There are two kinds of mini app linking, one "deep," one not:

1) A "launcher" deep link that opens your mini app homeUrl. This is just as if someone clicked the icon in the app launcher.

These look like:
https:// warpcast[dot]com/~/frames/launch?domain=farville[dot]farm

We are starting to render these as embeds in the feed so they look like other mini apps. You've probably seen them before as slim single line embeds too.

These deep links are nice because if you share it outside Farcaster you get a nice embed that will take you to the App Store if Warpcast isn't installed. (Try pasting one into iMessage). But they only open your mini app homeUrl, at least for now. 

So if your goal is to share externally, use this.

Example:

I'd start with what you want to do in your app and work from there. There are two kinds of mini app linking, one "deep," one not:

1) A "launcher" deep link that opens your mini app homeUrl. This is just as if someone clicked the icon in the app launcher.

These look like:
https:// warpcast[dot]com/~/frames/launch?domain=farville[dot]farm

We are starting to render these as embeds in the feed so they look like other mini apps. You've probably seen them before as slim single line embeds too.

These deep links are nice because if you share it outside Farcaster you get a nice embed that will take you to the App Store if Warpcast isn't installed. (Try pasting one into iMessage). But they only open your mini app homeUrl, at least for now. 

So if your goal is to share externally, use this.

Example: 
https://warpcast.com/~/frames/launch?domain=farville.farm