| name | event-trace |
| description | Trace the full event chain for one Claude Code session into an ordered timeline of every event type with tool_name and summary, highlighting gaps, out-of-order events, and failures. Reads /api/events?session_id= and /api/sessions/:id from the Agent Monitor dashboard. Use when debugging what a session actually did, step by step.
|
Event Trace
Build a chronological, annotated event timeline for a single session.
Input
The user provides: $ARGUMENTS
This is a session ID. It may also be:
latest / last — trace the most recently updated sessionerrors — trace the most recent session whose status is error
Data Sources
| Endpoint | Returns |
|---|
GET /api/sessions?limit=N | session list (used to resolve latest/errors and the target id) |
GET /api/sessions/:id | full session detail (status, model, cwd, started_at, ended_at, cost, nested agents + events) |
GET /api/events?session_id=X | the ordered event stream: event_type, tool_name, summary, data, timestamp |
Report Sections
1. Resolve the session
If $ARGUMENTS is a raw id, use it. If latest/last, call
GET /api/sessions?limit=1. If errors, call
GET /api/sessions?limit=10&status=error and pick the newest. Confirm the id
resolves via GET /api/sessions/:id; if not, report it as missing and stop.
2. Session header
From GET /api/sessions/:id: id, status, model, cwd, started_at → ended_at,
total duration, cost (USD to 4 decimals), and counts (events, agents).
3. Ordered timeline
From GET /api/events?session_id=X, list every event in timestamp order. One row
per event:
| # | time | Δ since prev | event_type | tool_name | summary |
Cover all event types present: SessionStart, PreToolUse, PostToolUse, Stop,
SubagentStop, Compaction, APIError, TurnDuration, Notification, SessionEnd.
4. Gap & failure highlights
Annotate the timeline:
- Gaps: any Δ > 30s between consecutive events — mark ⏳ and note the wait.
- Unpaired tool calls: a PreToolUse with no matching PostToolUse (same
tool_name, next in stream) — mark ⚠️ "no completion recorded".
- Failures: APIError events and PostToolUse whose
summary/data indicates
an error — mark ❌ with the error text.
- Compaction: mark ♻️ and note it resets the visible token baseline.
- Missing bookends: no SessionStart at the head or no Stop/SessionEnd at the
tail of an ended session — mark 🚩.
5. Verdict
One line: CLEAN, GAPS DETECTED, or FAILURES PRESENT — with the count of each
flag type and the single most likely thing to investigate next.
Output
- Markdown timeline table, events in strict timestamp order.
- Status glyphs inline: ✅ ok, ❌ error, ⚠️ warning/unpaired, ⏳ gap, ♻️ compaction, 🚩 missing bookend.
- Currency in USD to 4 decimals.
- Cite only event data returned by the API — do not invent timestamps or summaries.
- If the dashboard is unreachable, tell the user to start it with
npm start from the repo root.
