Diagnose

Use this workflow only after the explicit opt-in described in the frontmatter. A normal bug report or debugging request does not opt in to this skill.

Find and explain the cause of a symptom with 100% operational confidence.

Start from the user's concrete anchor: file, route, error, log, screen, branch, artifact, or reproduction step. Consult relevant architecture notes, ADRs, glossaries, and test docs. Inspect code, run safe tools or tests, and analyze existing artifacts.

Explicit invocation of Diagnose constitutes approval for behavior-neutral temporary instrumentation within the requested scope. Ask separately only for risky actions, inaccessible-state reproduction, or mutations that affect product behavior or external systems.

References

Load only what applies:

• Browser or React web: browser-react.md
• iOS, Android, React Native, macOS, TV, or physical device: app-device.md
• Logs, runtime probes, metrics, or debug hooks: instrumentation.md

Evidence Loop