diagnoselisted

# Diagnose A discipline for hard bugs. Skip phases only when explicitly justified. When exploring the codebase, build a clear mental model of the relevant modules and check any ADRs or design notes in the area you're touching. ## Redact This skill has you show commands, outputs, and captured artifacts. Redact every secret first: write `<REDACTED>` in its place. Build loops against env vars so credentials stay in the environment, not in what you show. Captured artifacts (HAR files, log dumps) carry auth headers — quote only the lines that carry signal. If redacted output isn't enough to diagnose, say so and ask the user. ## Phase 1 — Build a feedback loop **This is the skill.** Everything else is mechanical. If you have a fast, deterministic, agent-runnable pass/fail signal for the bug, you will find the cause — bisection, hypothesis-testing, and instrumentation all just consume that signal. If you don't have one, no amount of staring at code will save you. Spend disproportionate effort here. **Be aggressive. Be creative. Refuse to give up.** ### Ways to construct one — try them in roughly this order 1. **Failing test** at whatever seam reaches the bug — unit, integration, e2e. 2. **Curl / HTTP script** against a running dev server. 3. **CLI invocation** with a fixture input, diffing stdout against a known-good snapshot. 4. **Headless browser script** (Playwright / Puppeteer) — drives the UI, asserts on DOM/console/network. 5. **Replay a captured trace.** Save a real