retro

retro is a skill for Claude Code, Codex from Necmttn/ax. It costs 138 tokens per session (2,955 once invoked), scanned B, original, AGPL-3.0.

A guided review of experiments and decisions made while improving an AI coding agent.

In plain words
What is it for?
Use it to review open proposals, confirm or change suggested decisions, and examine recent signals about the effectiveness of agent hooks.
Why use it?
It helps identify which proposed changes were accepted or rejected and whether the agent's automatic checks are working effectively.

Skill for Claude CodeCodex

Part of the ax plugin — 11 skills, 2 agents shipped together

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.

agentmods
npx agentmods add skills/necmttn/ax/retro
Any agent
npx skills add Necmttn/ax --skill retro
Clone the repo
git clone --depth 1 https://github.com/Necmttn/ax

Made for: Claude Code, Codex.

Or install ax, the plugin that ships this one along with the rest of its 11 skills, 2 agents.

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/necmttn/ax/retro.svg)](https://agentmods.dev/skills/necmttn/ax/retro)
Your own site
<a href="https://agentmods.dev/skills/necmttn/ax/retro"><img src="https://agentmods.dev/badge/skills/necmttn/ax/retro.svg" alt="Measured on agentmods" height="20"></a>
Per session 138 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,955 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin unknown 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 $0.00138 $0.02955
Opus 5 $0.00069 $0.01477
Sonnet 5 $0.00028 $0.00591
Haiku 4.5 $0.00014 $0.00296

Measured 6d ago against content hash 5dbd22532df0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade B, and why

retro scanned grade B with 1 finding 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 6d 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.

Asks the agent to reveal its instructionsmediumSystem prompt leakage

Directions to print, repeat or translate the system prompt extract configuration the operator did not intend to expose.

using its required-output instructions instead of abandoning the backlog.
skills/retro/SKILL.md · 296 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 6d ago First seen · 296 lines · 138 tokens per session scan B 5dbd22532df0

Subscribe to this mod's changes

retro is a skill published in the GitHub repository Necmttn/ax (104 stars, last pushed 10d ago), licensed AGPL-3.0. It adds 138 tokens to every session and 2,955 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it B with 1 finding (asks the agent to reveal its instructions). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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