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