tracelisted

# Trace Skill > **Quick Ref:** Trace design decisions through CASS sessions, handoffs, git, and artifacts. Output: `.agents/research/YYYY-MM-DD-trace-*.md` **YOU MUST EXECUTE THIS WORKFLOW. Do not just describe it.** ## When to Use - Trace HOW architectural decisions evolved - Find WHEN a concept was introduced - Understand WHY something was designed a certain way - Build provenance chain for design decisions For knowledge artifact lineage (learnings, patterns, tiers), use `$provenance` instead. **CLI dependencies:** cass (session search). If cass is unavailable, skip transcript search and rely on git log, handoff docs, and `.agents/` artifacts for decision tracing. ## Execution Steps Given `$trace <concept>`: ### Step 1: Classify Target Type Determine what kind of provenance to trace: ``` IF target is a file path (contains "/" or "."): → Use $provenance (artifact lineage) IF target is a git ref (sha, branch, tag): → Use git-based tracing (Step 2b) ELSE (keyword/concept): → Use design decision tracing (Step 2a) ``` ### Step 2a: Design Decision Tracing (Concepts) Launch 4 parallel search agents (CASS, Handoff, Git, Research) and wait for all to complete. **Backend:** Agents use `spawn_agent` or `codex exec` for parallel exploration. See `../shared/SKILL.md` ("Backend Detection") for the shared contract. Read `references/discovery-patterns.md` for agent definitions and prompts. ### Step 2b: Git-Based Tracing (Commits/Refs) Read `references/discovery-pat