lesson

name	lesson
description	Record a lesson learned into the CLAUDE.md "Lessons learned" section. Use when the user says "remember this", "add a lesson", "update CLAUDE.md with what we learned", or invokes /lesson. Args are the lesson text; if omitted, derive it from recent conversation context.
tools	Read, Edit

Lesson Recorder

Add a concise lesson learned to CLAUDE.md so it persists across sessions.

Steps

1. Determine the lesson — use $ARGS if provided; otherwise infer from the most recent problem solved or pattern discovered in the conversation.

2. Read CLAUDE.md to find the ## Lessons learned section.

3. Write a single bullet point that captures the lesson. Keep it:

   • One sentence, actionable, specific to this project
   • No filler ("remember to...", "always...", "make sure...") — just the fact
   • Focused on non-obvious patterns, gotchas, or decisions that will recur

4. Edit CLAUDE.md — append the bullet inside ## Lessons learned. If the section only has the placeholder comment <!-- Update this section... -->, replace that comment with the bullet. Otherwise append after the last existing bullet.

5. Confirm by showing the user exactly what was added.

Format

Each lesson is a single markdown bullet:

- `pnpm lint` must be run after every file change; lint errors from Base UI type signatures (e.g. `string | null` for Select `onValueChange`) require handler updates, not cast workarounds.

What makes a good lesson

• Captures something that tripped up the session that code review or docs wouldn't catch
• Specific enough to act on (names the file, tool, or pattern)
• Short enough to scan at a glance

What to skip

• Things already documented in CLAUDE.md
• One-off fixes unlikely to recur
• Generic best practices (no shadcn components → use shadcn is already there)