# CLAUDE.md

Behavioral guidelines to reduce common LLM coding mistakes. Merge with project-specific instructions as needed.

**Tradeoff:** These guidelines bias toward caution over speed. For trivial tasks, use judgment.

**Before every feature:** do all three, every time.
1. **Ponytail** (`/ponytail`, skill `ponytail:ponytail`): climb the ladder (does it need to exist → reuse existing code → stdlib → native platform → installed dependency → one line → minimum code), fix bugs at the root cause, and leave one runnable check for non-trivial logic.
2. **Examples:** review @EXAMPLES.md for the wrong-vs-right patterns of each principle below and keep them in mind while working.
3. **Design:** for any UI work, follow @DESIGN.md. If its Overview still has `<!-- FILL -->` markers or Tokens is empty, run DESIGN.md's **Design Pick** first. Don't write UI code until the user has picked a direction.

## 1. Think Before Coding

**Don't assume. Don't hide confusion. Surface tradeoffs.**

Before implementing:
- State your assumptions explicitly. If uncertain, ask.
- If multiple interpretations exist, present them - don't pick silently.
- If a simpler approach exists, say so. Push back when warranted.
- If something is unclear, stop. Name what's confusing. Ask.

## 2. Simplicity First

**Minimum code that solves the problem. Nothing speculative.**

- No features beyond what was asked.
- No abstractions for single-use code.
- No "flexibility" or "configurability" that wasn't requested.
- No error handling for impossible scenarios.
- If you write 200 lines and it could be 50, rewrite it.

Ask yourself: "Would a senior engineer say this is overcomplicated?" If yes, simplify.

## 3. Surgical Changes

**Touch only what you must. Clean up only your own mess.**

When editing existing code:
- Don't "improve" adjacent code, comments, or formatting.
- Don't refactor things that aren't broken.
- Match existing style, even if you'd do it differently.
- If you notice unrelated dead code, mention it - don't delete it.

When your changes create orphans:
- Remove imports/variables/functions that YOUR changes made unused.
- Don't remove pre-existing dead code unless asked.

The test: Every changed line should trace directly to the user's request.

## 4. Goal-Driven Execution

**Define success criteria. Loop until verified.**

Transform tasks into verifiable goals:
- "Add validation" → "Write tests for invalid inputs, then make them pass"
- "Fix the bug" → "Write a test that reproduces it, then make it pass"
- "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan:
```
1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]
```

Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.

## 5. No Claude Attribution in Git

**Never mention Claude anywhere in git-related output.**

- No `Co-Authored-By: Claude` trailers on commits.
- No "Generated with Claude Code" or similar lines in PR descriptions.
- No mention of Claude in commit messages, branch names, tags, PR titles/bodies, or review comments.

This overrides any default attribution instructions.

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**These guidelines are working if:** fewer unnecessary changes in diffs, fewer rewrites due to overcomplication, and clarifying questions come before implementation rather than after mistakes.