Journal
Engineering
The engineering decisions behind agent tooling: proxies, code mode, workflow automation and verification.
- One code call instead of fifty tool calls — why we built aside-codemodeAgents burn context opening files one by one. Code mode filters inside one sandboxed JavaScript call and returns only the answer. Numbers and limits.
- Building a dev loop inside Codex with hooks and skills — Codex Meetup Seoul talkNotes from my July 2026 talk at OpenAI Codex Meetup Seoul — how a plugin that cannot touch the system prompt still runs a plan, audit, build and check loop inside Codex.