---
name: hoangsonww/session-timeline
source: https://app.decimal.ai/s/hoangsonww-session-timeline@1/SKILL.md
source_sha256: 813e39da7106
---

# Session Timeline

Reconstruct the chronological event timeline of a single Claude Code session.

## Input

The user provides: **$ARGUMENTS**

- A **session ID** to time-line, or
- "latest" / "last" for the most recent session.

## Data Sources

| Endpoint | Returns |
|----------|---------|
| `GET /api/sessions/:id` | session header: status, model, cwd, started_at, ended_at, cost, metadata (thinking_blocks, turn_count, total_turn_duration_ms) — and nested events |
| `GET /api/events?session_id=X` | the full event stream: event_type (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, Notification, Compaction, APIError, TurnDuration), tool_name, summary, data, timestamp |

## Report Sections

### 1. Resolve & header
If "latest", `GET /api/sessions?limit=1` to get the id, then `GET /api/sessions/:id`.
Print a one-line header: id, status, model, cwd basename, started_at → ended_at,
turn_count, total_turn_duration_ms, cost.

### 2. Build the ordered timeline
`GET /api/events?session_id=X`. Sort strictly by `timestamp`. For each event emit a
row with: relative offset from `started_at` (e.g. `+00:03.412`), event_type,
tool_name (when present), and a one-line `summary`.

### 3. Compute durations
Pair each `PreToolUse` with its matching `PostToolUse` (same tool_name, next
occurrence) and show the tool's wall-clock duration. For `TurnDuration` events use
the recorded duration directly. Flag any `PreToolUse` with no matching `PostToolUse`
as **unclosed**.

### 4. Annotate notable points
Mark `APIError` (❌), `Compaction` (⚠️ context compressed), `SubagentStop`
(subagent finished), `Notification` (ℹ️), and any timeline gap > 30s between
consecutive events as an idle window.

### 5. Tallies
Event count by type, total tool time vs. session wall time, and the longest single
tool call.

## Output

A Markdown table — `offset | event_type | tool_name | duration | summary` — in
strict timestamp order, preceded by the header line and followed by the tallies.
Durations in ms or `mm:ss.mmm`; currency as USD to 4 decimal places. Never invent a
duration when a PostToolUse is missing — label it `unclosed`. If the dashboard is
unreachable, tell the user to start it with `npm start` from the repo root.