event-trace

event-trace is a skill for Claude Code, Codex from hoangsonww/Claude-Code-Agent-Monitor. It costs 73 tokens per session (808 once invoked), scanned A, original, MIT.

A timeline tool for one Claude Code session that orders every recorded event and includes tool names, summaries, gaps, out-of-order events, and failures. An event is a recorded action or state change during a run.

In plain words
What is it for?
Use it to trace a chosen, latest, or errored session from start to finish and inspect its agents, events, duration, and cost.
Why use it?
It makes the exact sequence of a session visible, which helps reveal where work stopped, failed, or behaved unexpectedly.

Skill for Claude CodeCodex

Written for Claude Code and Codex: $ARGUMENTS substitution, but also agents/openai.yaml present. Also seen: mentions Claude Code.

Part of the ccam-devtools plugin — 6 skills, 3 commands, 2 agents shipped together

Good fit Use it to trace a chosen, latest, or errored session from start to finish and inspect its agents, events, duration, and cost.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hoangsonww/claude-code-agent-monitor/event-trace
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill event-trace
Clone the repo
git clone --depth 1 https://github.com/hoangsonww/Claude-Code-Agent-Monitor

Made for: Claude Code, Codex.

Or install ccam-devtools, the plugin that ships this one along with the rest of its 6 skills, 3 commands, 2 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for event-trace

README.md
[![agentmods](https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/event-trace/github.svg)](https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/event-trace)
Your own site
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/event-trace"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/event-trace/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for event-trace

Your own site · 80×15
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/event-trace"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/event-trace.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 808 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00073 $0.00808
Opus 5 $0.00036 $0.00404
Sonnet 5 $0.00015 $0.00162
Haiku 4.5 $0.00007 $0.00081

Measured 9d ago against content hash e2369483bb24, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

event-trace scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/ccam-devtools/skills/event-trace/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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.

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 🚩.

Read the full file on GitHub · 74 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 74 lines · 73 tokens per session scan A e2369483bb24

Subscribe to this mod's changes

event-trace is a skill published in the GitHub repository hoangsonww/Claude-Code-Agent-Monitor (991 stars, last pushed 4d ago), licensed MIT. It adds 73 tokens to every session and 808 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.