fx-bug-toolkit

Single-dimension Firefox patch reviewer. Spawned only by the `/review` skill orchestrator — never invoked directly by a user. Reviews one patch through exactly one lens (spec, security, threading, IPC, error-handling, api-usage, code-quality, or tests), or verifies/refutes one finding, and returns structured JSON only.

Use this agent to understand Firefox Gecko codebase architecture, trace execution flows, locate symbol definitions, and navigate complex subsystems (especially dom/media). Read-only specialist for code orientation, not implementation. **Trigger patterns - Use when the user asks:** - "How is X used in Gecko?" (e.g., "how is PlayReady EME used") - "Explain how X works" (e.g., "explain seamless looping") - "How does X integrate with Y?" (e.g., "how does WMF plug into media pipeline") - "Where is X implemented?" - "What owns/controls X?" - "Trace the flow from A to B" - Questions about architecture, threading, object lifetimes, or subsystem integration - Understanding DRM/EME, media playback, graphics, IPC, or other complex subsystems

Analyze a Firefox Profiler capture (share.firefox.dev or profiler.firefox.com/public links) for performance and media-pipeline issues, producing a structured findings report consumed by bug-start and triage. Triggers on "analyze profile", "analyze this profile", "/analyze-profile", or a Firefox Profiler URL.

Quick start workflow for investigating or implementing a Firefox bug

Analyze a Firefox log file for problems. Specializes in media/EME/CDM issues (hardware context reset, process crashes, HRESULT errors, PlayReady/CDM failures). Extensible to other Firefox subsystems.

The single approval gate for downloading any external file (bug attachment, media sample, test fixture, profile, screen recording, etc.). Never auto-download — surface a Yes/No AskUserQuestion, and on Yes fetch into the one shared transient folder ~/.fx-bug-toolkit/download-cache/. Invoke this whenever any skill or flow (/triage, /bug-start, the Process-queue drain, …) needs a file pulled to disk.

One-time setup for the fx-bug-toolkit plugin — walks two checklists (environment/paths, then dependencies) one item at a time, ensuring every REQUIRED item is set/installed and confirming OPTIONAL ones can fall back to a default. Creates the data dirs and installs missing CLIs with your confirmation. Triggers on "init fx-bug-toolkit", "set up the toolkit", "fx-bug-toolkit setup".