retro

retro is a skill for Claude Code from optimiziramsi/skills. It costs 90 tokens per session (1,122 once invoked), scanned A, original, MIT.

A session wrap-up skill that collects lasting lessons from the work and places them in the project's instruction files. It includes checking where each lesson belongs and removing duplicates or outdated notes.

In plain words
What is it for?
Use it after an important session, a correction, a discovered pitfall, or when someone asks to save what was learned.
Why use it?
It prevents useful corrections and recurring mistakes from being forgotten or making the instruction system grow without control.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md.

Part of the optimiziramsi-skills plugin — 25 skills, 25 commands, 9 agents, 2 hooks shipped together

Good fit Use it after an important session, a correction, a discovered pitfall, or when someone asks to save what was learned.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/optimiziramsi/skills/retro
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 optimiziramsi/skills --skill retro
Clone the repo
git clone --depth 1 https://github.com/optimiziramsi/skills

Made for: Claude Code.

Or install optimiziramsi-skills, the plugin that ships this one along with the rest of its 25 skills, 25 commands, 9 agents, 2 hooks.

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 retro

README.md
[![agentmods](https://agentmods.dev/badge/skills/optimiziramsi/skills/retro/github.svg)](https://agentmods.dev/skills/optimiziramsi/skills/retro)
Your own site
<a href="https://agentmods.dev/skills/optimiziramsi/skills/retro"><img src="https://agentmods.dev/badge/skills/optimiziramsi/skills/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.

agentmods 80×15 button for retro

Your own site · 80×15
<a href="https://agentmods.dev/skills/optimiziramsi/skills/retro"><img src="https://agentmods.dev/badge/skills/optimiziramsi/skills/retro.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,122 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.
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 $0.00090 $0.01122
Opus 5 $0.00045 $0.00561
Sonnet 5 $0.00018 $0.00224
Haiku 4.5 $0.00009 $0.00112

Measured 9d ago against content hash ac953e6d01c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

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 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.

instructions/skills/retro/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Retro — route learnings, close the unit

This is how the instruction system self-updates without rotting. Harvest what this session taught, route each learning to the store that owns it, and keep the system lean.

Assumes the default .agent/ house layout: .agent/lessons/, .claude/rules/, .docs/, .agent/handoff.md, .agent/instructions-changelog.md. A project on a different layout (e.g. keeps docs/ at the repo root instead of .docs/) maps each to its own equivalent — the paths named in these skills are the convention, not a hard requirement.

1. Harvest

Scan the session for durable learnings:

  • user corrections ("no, do it this way"), confirmed conventions, owner decisions;
  • bugs whose root cause implies a rule; gotchas that cost real time;
  • a procedure that was wrong or missing.

Skip: session narration, one-off trivia, anything already recorded, secrets/personal data. A learning qualifies only if it would change how a future session acts — git history already holds the narrative.

2. Route each learning to its store

  • learning: Durable fact, gotcha, working agreement, engineering lesson store: .agent/lessons/ via: the lessons skill

  • learning: Binding rule (must / never) store: the project's binding-rule home — .claude/rules/*.md only if the project uses that layer, else its canonical rule book / CLAUDE.md (never create a new instruction layer) via: add the enforcement tag; if you write [ENFORCED], the guard must exist — extend a hook in the same change, else tag it [HONOR]

  • learning: Repeatable procedure that was wrong or missing store: the matching skill's steps via: edit the skill

  • learning: Architecture / code-shape / recipe store: .docs/ via: edit the doc

  • learning: Volatile "where we left off" state store: .agent/handoff.md via: the handoff skill — NOT here

  • learning: Enforcement gap (a checkable violation slipped through) store: a hook via: add / extend the guard

Read the full file on GitHub · 103 lines

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 · 103 lines · 90 tokens per session scan A ac953e6d01c1

Subscribe to this mod's changes

retro is a skill published in the GitHub repository optimiziramsi/skills (2 stars, last pushed 19d ago), licensed MIT. It adds 90 tokens to every session and 1,122 once invoked, about $0.0005 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 2026-08-31.

Related

Other skills, from other repositories

media-ingest

Ingest video, audio, PDF, book, screenshot, and GitHub repo content into the brain. Multi-format handling with entity extraction and backlink propagation. Covers video-ingest, youtube-ingest, and book-ingest subtypes.

garrytan/gbrain · 52 tokens

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

Cortex

Operate Cortex, the LifeOS memory system — the typed Knowledge Archive (People, Companies, Ideas, Research with typed related: links) plus recall of prior work sessions, ISAs, and conversations. Search, add, harvest, develop, ingest, distill, graph-navigate, recall. USE WHEN cortex, knowledge, knowledge base, search…

danielmiessler/LifeOS · 196 tokens

memory

Use when the user asks to remember, recall, forget, update, search, or inspect durable OpenSquilla memory, including profile facts in USER.md and long-term notes in MEMORY.md or memory//.md.

opensquilla/opensquilla · 44 tokens

ha-data-stores

Map of Hope Agent's local data stores and safe read-only query workflow. Use when the user asks where Hope Agent stores data, wants to inspect sessions/messages/memory/logs/background jobs/knowledge indexes/settings, asks the model to query local app data, or debugging requires checking persisted state. Trigger…

shiwenwen/hope-agent · 115 tokens

establishing-project-context

Use when the user asks to establish shared project language, or project work exposes a conflicting, renamed, or deprecated domain term that needs active semantic modeling. Routine small tasks stay on the fast path.

GanyuanRan/Aegis · 45 tokens