How to plan agent coding projects
(updated June 15th)Coding
Update 2026-06-15: I’m making heavy use of the Compound Engineering plugin. Its planning skill is great.
Making something? Planning is the most important part. With a good plan, you’re much less likely to waste time building the wrong thing, the wrong way.
Quick tips on planning:
- Mindset: you’re part of a team. Your agent is a product designer, and an engineer. Work together to make a great plan.
- Start by telling the agent about your problem—not the thing you think you want to build.
- Ask yourself, and your agent: what are the stakes here? Is it worth spending minutes, hours or days to solve this? Do a BOTEC.
- Ask the agent to brainstorm ways to solve the problem. Try requesting that brainstorm before you share your own thoughts on what to build.
- If the agent is too eager to switch from thought partnership to building, use question mode.
- Consider wireframing user interfaces before you build a working app. When you see a wireframe, you’ll have insights about what you need. It’s much faster to iterate on wireframes than a fully working prototype.
- After open discussion, switch to plan mode (
Shift + Tab). - Review the agent’s plan carefully. Ask it to explain things you don’t understand, or that strike you as questionable.
- Make big plans, so the agent can run independently for longer. Ask it to build the whole thing; assign 10 tickets at a time.
- Your plan should usually include “comprehensively test using Chrome” and “do code review”. Make sure the agent can use Chrome. To test a browser extension, use this skill.
- For web apps, use an agent-friendly framework like Next.js or Convex. Deploy to Vercel or Railway.
- For planning, Codex 5.4 is as good or better than Opus 4.6. YMMV.
- For big projects, consider writing a full PRD. If you’re doing this often, try ChatPRD.
- When planning, consider using fast mode (
/fast on). You’ll save a bunch of time, and the cost may make you think harder.1 - For difficult projects, ask several models.
Footnotes
With Claude Code, you’ll typically spend $5–25 per plan. On Codex, fast mode uses your ChatGPT Pro plan quota at 2x. ↩