Farcaster Devs

how is it possible to generate key metadata + sig ahead of time when registering rids/keys through the bundler — when you don’t know what the rid will be ahead of time since it is issued during the transaction?

The fid isn't part of the key registration signature, we use the owner address instead. So it really means "add key to this account's current FID":

The fid isn't part of the key registration signature, we use the owner address instead. So it really means "add key to this account's current FID":
 https://github.com/farcasterxyz/contracts/blob/dec97bd5cc89712d93ba18be40ae2ce057696f48/src/KeyGateway.sol#L32

I'm eth newbie..just learning
(working on @farcaster)

terminally.online

but the fid is part of the signed key request validator check, which gets called by the key registry during runtime and requires u to have signed over the fid ahead of time? 

I was trying to piece this together on the published bundler tests but the fuzzing abstracts just enough of what’s happening for me to miss it

Ah, yeah. That fid identifies the entity *requesting to add the key*, e.g. Warpcast or Neynar or Supercast. So it's the fid of an app, not a user.