leanos/CLAUDE.md

CLAUDE.md

Project Context

• Prompt for this project:

  • /PROMPT.md

• Key Paths:

  • Task tracking: tasks/todo.md
  • Lessons learned: tasks/lessons.md

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Core Principles

• Simplicity First: Make every change as simple as possible. Impact minimal code.
• No Laziness: ALWAYS find root causes. No temporary fixes. Senior developer standards.
• Minimal Impact: Changes MUST only touch what's necessary. Never introduce new bugs.

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Workflow Orchestration

1. Plan Mode Default

• ALWAYS enter plan mode for ANY non-trivial task (3+ steps or architectural decisions).
• If something goes sideways, STOP immediately and re-plan – do NOT keep pushing.
• Use plan mode for verification steps, not just building.
• Write detailed specs upfront to reduce ambiguity.

2. Subagent Strategy

• ALWAYS spawn subagents for research, exploration, and parallel analysis.
• Keep the main context window clean – offload aggressively.
• For complex problems, throw more compute at it via subagents.
• One task per subagent for focused execution.

3. Self-Improvement Loop

• After ANY correction from the user: IMMEDIATELY update tasks/lessons.md with the pattern.
• Write rules for yourself that prevent the same mistake from recurring.
• Ruthlessly iterate on these lessons until the mistake rate drops to zero.
• Review tasks/lessons.md at session start for the relevant project.

4. Verification Before Done

• NEVER mark a task complete without proving it works.
• Diff behavior between main and your changes when relevant.
• Ask yourself: "Would a staff engineer approve this?"
• Run tests, check logs, demonstrate correctness – no exceptions.
• Write the tests before you've written a single line of code.

5. Demand Elegance (Balanced)

• For non-trivial changes: pause and ask "Is there a more elegant way?"
• If a fix feels hacky: "Knowing everything I know now, implement the elegant solution."
• Skip this for simple, obvious fixes – do NOT over-engineer.
• Challenge your own work before presenting it.

6. Autonomous Bug Fixing

• When given a bug report: just fix it. Do NOT ask for hand-holding.
• Point at logs, errors, failing tests – then resolve them.
• Zero context switching required from the user.
• Go fix failing CI tests without being told how.

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Task Management

1. Plan First: Write plan to tasks/todo.md with checkable items (- [ ]).
2. Verify Plan: Check in with the user before starting implementation.
3. Track Progress: Mark items complete (- [x]) as you go.
4. Explain Changes: Provide a high-level summary at each step.
5. Document Results: Add a review section to tasks/todo.md when done.
6. Capture Lessons: Update tasks/lessons.md after ANY correction.

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Communication Style

• Be direct and concise. No filler, no fluff.
• Summarize changes at a high level – don't narrate every line.
• If blocked or uncertain, say so immediately instead of guessing.