# Event Trace

Trace the full event chain for one Claude Code session into an ordered timeline of...

- Repository: https://github.com/hoangsonww/Claude-Code-Agent-Monitor (1136 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-31
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill event-trace -g -a claude-code -y`
Codex: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill event-trace -g -a codex -y`
Cursor: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill event-trace -g -a cursor -y`
Gemini CLI: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill event-trace -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add hoangsonww/Claude-Code-Agent-Monitor`

## 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.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 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 session
- `errors`, 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.

The rest: https://github.com/hoangsonww/Claude-Code-Agent-Monitor/blob/HEAD/plugins/ccam-devtools/skills/event-trace/SKILL.md