Session Investigator

by evalstate

Session Investigator is an AI Engineering skill for Claude Code, published by evalstate in fast-agent.

3.9K stars434 forkson evalstate/fast-agentAdded 2026/08/16Repository updated 2026/08/14

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a2aacpagentagent-frameworkagent-skillsclimcpmcp-clientmcp-serverpythonskillstui

Install in seconds

Install Session Investigator

Copy Session Investigator into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/evalstate/fast-agent/tree/main/examples/hf-toad-cards/skills/session-investigator ~/.claude/skills/session-investigator

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/evalstate/fast-agent.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: examples/hf-toad-cards/skills/session-investigator/SKILL.md in evalstate/fast-agent
Installs to: ~/.claude/skills/session-investigator
Collection: One of 2 skills cataloged from this repository
Category: AI Engineering — 2451 skills

What Session Investigator does

Session Investigator examines fast-agent session and history files to diagnose issues like unexpected session endings, tool loops, and sub-agent trace correlation. Use it when analyzing conversation flow, timing, tool call/result pairing, and common failure patterns.

Session Investigator is cataloged under AI Engineering on DirSkills. Session Investigator comes from a repository tagged a2a, acp, agent, agent-framework and agent-skills.

Documentation

README

Excerpt

Session Investigator

Diagnose fast-agent session issues by examining session and history files.

Session Directory Structure

Sessions are stored in .fast-agent/sessions/<session-id>/:

2601181023-Kob2h3/
├── session.json              # Session metadata
├── history_<agent>.json      # Current agent history
└── history_<agent>_previous.json  # Previous save (rotation backup)

Session IDs encode creation time: YYMMDDHHMM-<random> (e.g., 2601181023 = 2026-01-18 10:23).

Key Files

session.json

This is the opening of the README. Read the full README on GitHub.

Frequently asked about Session Investigator

What else does evalstate publish alongside Session Investigator?
Session Investigator is one of 2 skills that DirSkills catalogs from evalstate/fast-agent, the repository it ships in. Its siblings there include PR Writing Review. Each one is a separate skill with its own page in this directory, installs the same way Session Investigator does, and is maintained by evalstate in that same repository. The rest of the collection is listed on the evalstate/fast-agent page.
How does Session Investigator compare to other AI Engineering skills?
Session Investigator ranks #566 by stars among the 2451 AI Engineering skills in this catalog. The most-starred ones next to it are Architecture Decision Records, AI-First Engineering and Agentic OS. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Session Investigator against them. Open each page to compare what they document and how they install.