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.
npx skills add JustinThomas2/agentrc --skill session-retrogit clone --depth 1 https://github.com/JustinThomas2/agentrcWrote 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.
[](https://agentmods.dev/skills/justinthomas2/agentrc/session-retro)<a href="https://agentmods.dev/skills/justinthomas2/agentrc/session-retro"><img src="https://agentmods.dev/badge/skills/justinthomas2/agentrc/session-retro/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.
<a href="https://agentmods.dev/skills/justinthomas2/agentrc/session-retro"><img src="https://agentmods.dev/badge/skills/justinthomas2/agentrc/session-retro.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00047 | $0.00590 |
| Opus 5.5 | $0.00019 | $0.00236 |
| Sonnet 5.5 | $0.00009 | $0.00118 |
| Haiku 4.5 | $0.00005 | $0.00059 |
Grade A, and why
session-retro 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TRANSCRIPT = $ARGUMENTS - if that reads as a literal placeholder instead of a file path, treat it as empty: the analyzer will find the current project's most recent transcript on its own.
The retro must cost a small fraction of the session it analyzes. All number-crunching happens in the bundled script; NEVER read the raw transcript into context - not even excerpts. Work only from the script's printed summary plus what you already remember of this session. Read-only throughout: analyze and report, change nothing.
Your task
- Run the analyzer bundled in this skill's directory:
python3 <skill-dir>/analyze.py [TRANSCRIPT]It picks the newest transcript for the current project under~/.claude/projects/unless a path is given. If it errors (e.g. running under a harness that stores transcripts elsewhere), say so and ask me for the transcript path instead of guessing. - Interpret the summary. The interesting signals:
- the largest tool results, and whether each was necessary at that size (whole-file Read where a range or search would have done? verbose command output that could have been filtered?)
- repeated calls to the same target - re-reads and retry loops
- cache behavior:
readis re-served context and cheap;createdplusfresh inputis what actually grew the bill, and final context is how full the window got - anything you remember doing the long way (trial-and-error loops, work that a subagent or a narrower query could have done cheaper)
- Report, briefly - the whole retro should be a screenful:
- a high-level breakdown of where tokens went
- an honest assessment of which spend was justified and which was avoidable, tied to specific entries in the summary
- 2-3 concrete takeaways for future sessions Keep it to observations about this session; do not turn the takeaways into config or instruction changes without being asked.
Notes
- Deliberately manual-only: an automatic end-of-session run (a SessionEnd hook, possibly gated to long sessions) was considered and deferred - see issue #15. Record a new issue instead of adding a hook here.
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.
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.
- 2mo ago First seen · 52 lines · 47 tokens per session scan A 8c36f2f1ca13
session-retro is a skill published in the GitHub repository JustinThomas2/agentrc (2 stars, last pushed 3mo ago), licensed MIT. It adds 47 tokens to every session and 590 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.
Other skills, from other repositories
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
insight-error-page
Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…