Okay...and continue to work up the levels? Why do you think OAuth might be limiting? Why do you think they started building subagents first? What is the difference between subagents and products like Aider?

If they were able to wrap the API directly, this is relatively easy to implement but they have to do this within Claude Code which is based on giving a prompt/hiding API access. This is obvious if you think carefully about what Claude Code is, what requests it is sending to the API, etc.