Look Before It Leaps
You have your requirements. You have your look. You have your screen rules. Now it’s almost time to build.
Almost. There’s one more step, and it’s the one that saves the most headaches: turning everything into a plan, and reading it before a single file changes.
That’s what plan mode is for.
What Plan Mode Does
In plan mode, Claude can:
- Read your files, your notebook, your requirements, your photos.
- Think and ask you questions.
- Write a plan and show it to you.
But it can’t:
- Change any of your files.
- Run commands that change things.
Plan mode is Claude with its hands in its pockets. It can look at everything, but it can’t touch anything until you say so.
To turn it on, press Shift+Tab until the bottom of the screen says plan mode.
Asking for the Plan
In plan mode, ask for a plan built from your requirements:
Read @REQUIREMENTS.md and @CLAUDE.md. Make a step by step plan to build this website. Keep each step small, so I can check the result after every one. Don't build anything yet.Claude reads everything, thinks it through, and shows you the plan.
A good plan has small milestones (steps that each end with something you can see and check):
| Too big | Just right |
|---|---|
| “Build the whole website” | “Set up the site, and show a blank page on localhost” |
| “Do all the pages” | “Build the home page with the name and photo” |
| “Make it look good” | “Apply the colors and fonts from CLAUDE.md to the home page” |
Now Read It. Really Read It.
This is the most important moment of the whole build. Go through the plan line by line, and for each step ask:
- Is this something I asked for?
- Is anything from my requirements missing?
- Is anything here that I said was “not now”?
- Is any step too big to check in one go?
Then push back, in plain words:
Remove step 4, the blog is "not now". Add a step for putting captions under the drawings. And split step 2 into two smaller steps.Go back and forth as many times as you like. Changing a plan is free. (Remember the cost-of-change note?)
Save the Plan
When the plan looks right, have it saved as a file, so it survives /clear and future chats:
This plan looks good. Save it as PLAN.md, with a checkbox next to each step.To write the file, Claude needs to leave plan mode. It will ask you first. Approving is the gate opening: from here on, it can build.
Requirements say what. The plan says in what order. And you approve both before anything gets built.
Finally, point your notebook at both files, so every future chat knows where to look:
Add to CLAUDE.md: the requirements are in REQUIREMENTS.md and the build plan is in PLAN.md. Tick off each step in PLAN.md when it's done.Try it
Switch to plan mode, ask Claude for a step by step plan for your website, and read every line of it. Push back at least once, even on something small. Then save it as PLAN.md.
See an example prompt
Press Shift+Tab until you see plan mode, then:
Read @REQUIREMENTS.md and @CLAUDE.md. Make a step by step plan to build my website, with small steps I can check one at a time. Don't build anything yet.After you’ve read it and made your changes:
Looks good. Save it as PLAN.md with a checkbox next to each step, and note in CLAUDE.md that the plan lives there.