Kicking around some ideas on how to make frames more powerful for interactive casts. 

Reply or DM if you have thoughts!

Technowatermelon. Elder Millenial. Building Farcaster. 

nf.td/varun

2. Contributing to @stephancill's comment on that, I could see a flow similar to Cast Actions:
  a. "Factory Frame" can be added in a specific "Factory Frames" list by visiting a deeplink that points to route accepting GET method which has a similar to Cast Action GET response: name, description, icon etc.

b. Such "Factory Frames" are shown in a list (like "Cast Actions") but have a specific button preserved in UI only when you have the "Cast" dialog active.
  c. On click, POST request with FrameAction payload is sent to the route with CastId.hash=0x(0) and CastId.fid=<user's fid> with current cast text set at input_text

f. This `embedURL` is automatically appended to the end of the Cast.

d. After c., an "Ephemeral Frame" pops up.
e. Such an "Ephemeral Frame" should send a 200 Reply with Content-Type: JSON having { embedURL: string } which will have the constructed Embed URL. On receiving, the modal should be dismissed automatically.