You don't need to mess with certificates - you can point CC at a HTTP endpoint and it'll happily play along.
If you build a DIY proxy you can also mess with the prompt on the wire. Cut out portions of the system prompt etc. Or redirect it to a different endpoint based on specific conditions etc.
Have tried with gemini-cli and claude-code both, it works, honestly, it should work with most if not all cli clients
Working on this feature right now!! Thank you for the suggestion, will start the branch for it... Whent think of improving the context window usage, now that with an http relay we can start thinking of intercepting the context window, anything that you think could be cool to implement?
Have you tried this with Gemini? or Codex?