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 : 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 Task(subagent_type="Explore") which maps to task(subagent_type="explore") in OpenCode. See skills/shared/SKILL.md ("Runtime-Native Spawn Backend Selection") for the shared contract. Read references/discovery-patterns.md for agent definitions and prompts. Step 2b: Git-Based Tracing (Commits/Refs) Read references/discovery-patterns.md for git-based tracing commands. Step 3: Build Timeline Merge results from all sources into a single chronological timeline (oldest first). Deduplicate same-day/same-session events. Every claim needs a source citation. Step 4: Extract Key Decisions For each event in timeline, identify: What changed: The decision or evolution Why: Reasoning if available Who: Session/author/commit author Evidence: Link to source (session path, file, commit) Step 5: Write Trace Report Write to: .agents/research/YYYY-MM-DD-trace-.md Read references/report-template.md for the full report format and deduplication rules. Step 6: Report to User Tell the user: Concept traced successfully Timeline of evolution (key dates) Most significant decisions Location of trace report Related concepts to explore Handling Edge Cases Read references/edge-cases.md for handling: no CASS results, no handoffs, ambiguous concepts (>20 results), and all-sources-empty scenarios. General principle: continue with remaining sources and note gaps in the report. Key Rules Search ALL sources - CASS, handoffs, git, research Build timeline - chronological evolution is the goal Cite evidence - every claim needs a source Handle gaps gracefully - not all concepts are in all sources Write report - trace must produce .agents/research/ artifact Relationship to /provenance Skill Purpose Input Output /provenance Artifact lineage File path Tier/promotion history /trace Design decisions Concept/keyword Timeline of evolution Use /provenance for: "Where did this learning come from?" Use /trace for: "How did we decide on this architecture?" Examples

Trace a design decision

/trace "three-level architecture"

Trace a role/concept

/trace "Chiron"

Trace a pattern

/trace "brownian ratchet"

Trace a feature

/trace "parallel wave execution" Tracing an Architectural Decision User says: /trace "agent team protocol" What happens: Agent classifies target as concept (not file path or git ref) Agent launches 4 parallel agents: CASS search, handoff search, git log search, research artifact search CASS finds 8 sessions mentioning "agent team", handoff finds 2 docs, git finds 3 commits, research finds 1 analysis Agent builds chronological timeline from 2026-01-15 (first mention) to 2026-02-08 (latest update) Agent extracts 5 key decisions: initial SendMessage design, TeamCreate addition, deliberation protocol, in-process mode, delegate mode Agent writes trace report to .agents/research/2026-02-13-trace-agent-team-protocol.md with full timeline and citations Result: Complete evolution timeline showing how agent team protocol developed across 7 sessions with source citations. Tracing from Git Commit User says: /trace abc1234 What happens: Agent detects git ref format (short sha) Agent runs git-based tracing commands to get commit details, changed files, related commits Agent uses git log --grep to find related work Agent searches .agents/ for contemporary research/plans Agent builds timeline focused on that specific change Agent writes report showing commit context, what changed, why (from commit message and related docs) Result: Trace report links commit to broader design context from surrounding artifacts. Troubleshooting Problem Cause Solution CASS returns no results Session search not installed or query too specific Check which cass . If missing, skip CASS and rely on handoffs/git/research. Try broader query terms. Timeline has gaps Not all decisions documented in searchable artifacts Note gaps in report. Suggest interviewing team members or checking Slack/email archives for missing context. Too many results (>50 matches) Very broad concept or high-frequency term Read references/edge-cases.md for ambiguous concept handling. Narrow query or filter by date range. Ask user for more specific aspect to trace. Empty trace report (all sources failed) Concept genuinely undocumented or typo Verify spelling. Try synonyms. Report to user: "No documented history found. This may be a new concept or may need different search terms."