# Session Compare

Compare two sessions side-by-side using Agent Monitor data, per-model token usage...

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

## Install

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

## Description

Compare two sessions side-by-side using Agent Monitor data, per-model token usage (input/output/cache_read/cache_write + compaction baselines), pricing engine cost breakdowns, workflow intelligence (complexity scores, tool flow transitions, subagent effectiveness), session metadata (thinking_blocks, turn_count, turn_duration_ms, usage_extras), and full event timelines with all 10+ event types.

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

# Session Compare

Compare two Claude Code sessions side-by-side using Agent Monitor data.

## Input

The user provides: **$ARGUMENTS**

This may be:
- Two session IDs: "abc123 def456"
- "best vs worst", compare highest and lowest productivity sessions
- "latest 2", compare the two most recent sessions
- A session ID + "vs average", compare one session against the baseline

## Procedure

1. **Identify sessions to compare**:
   - If two IDs given: fetch both from `http://localhost:4820/api/sessions/{id}`
   - If "best vs worst": fetch sessions, score by completion + cost efficiency, pick extremes
   - If "latest 2": `GET /api/sessions?limit=2` (default sort: most recently updated first)
   - If "vs average": fetch session + compute averages from last 50 sessions

2. **Gather detailed data** for each session:
   - Session metadata: `GET /api/sessions/{id}`
   - Events: `GET /api/events?session_id={id}`
   - Agents: `GET /api/agents?session_id={id}`
   - Cost: `GET /api/pricing/cost/{id}`

3. **Build comparison**:

   ### Overview Comparison
   | Metric | Session A | Session B | Difference |
   |--------|-----------|-----------|-----------|
   | Status | completed | error |, |
   | Model | sonnet-4 | sonnet-4 | same |
   | Duration | 12m 34s | 45m 12s | +32m 38s |
   | Total Cost | $0.0234 | $0.1456 | +522% |
   | Events | 45 | 187 | +315% |
   | Tools Used | 8 | 12 | +4 |
   | Error Count | 0 | 7 | +7 |
   | Agents | 2 | 5 | +3 |

   ### Token Comparison
   | Token Type | Session A | Session B | Difference |
   |-----------|-----------|-----------|-----------|
   | Input | N | N | ±N% |
   | Output | N | N | ±N% |
   | Cache Read | N | N | ±N% |
   | Cache Write | N | N | ±N% |
   | Efficiency | N% | N% | ±N% |

   ### Tool Usage Comparison
   - Tools unique to Session A
   - Tools unique to Session B
   - Shared tools with usage count comparison
   - Error rate per tool in each session

The rest: https://github.com/hoangsonww/Claude-Code-Agent-Monitor/blob/HEAD/plugins/ccam-insights/skills/session-compare/SKILL.md