history-hygiene

history-hygiene is a skill for Claude Code, Codex from github/gh-aw. It costs 18 tokens per session (366 once invoked), scanned A, original, MIT.

A rule for recording only confirmed final decisions and outcomes in a project history file.

In plain words
What is it for?
It helps maintain accurate history.md records after decisions or implementation work are settled.
Why use it?
It prevents future agents from relying on outdated requests, reversed decisions, or unfinished plans.

Skill for Claude CodeCodex ✓ vendor

Written for no agent in particular: nothing here depends on one.

Good fit It helps maintain accurate history.md records after decisions or implementation work are…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/github/gh-aw/history-hygiene
About the project

GitHub Agentic Workflows is a GitHub CLI extension that lets developers define AI-assisted repository automation in Markdown and run it through GitHub Actions. It is intended for tasks requiring interpretation or reasoning, such as issue triage, pull-request review, CI investigation, documentation maintenance, and dependency analysis. The catalogue entries provide skills and agents for working with these workflows.

github/gh-aw · 5,108 stars · on GitHub · gh.io

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 github/gh-aw --skill history-hygiene
Clone the repo
git clone --depth 1 https://github.com/github/gh-aw

Made for: Claude Code, Codex.

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 history-hygiene

README.md
[![agentmods](https://agentmods.dev/badge/skills/github/gh-aw/history-hygiene.svg)](https://agentmods.dev/skills/github/gh-aw/history-hygiene)
Your own site
<a href="https://agentmods.dev/skills/github/gh-aw/history-hygiene"><img src="https://agentmods.dev/badge/skills/github/gh-aw/history-hygiene.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 366 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 $0.00018 $0.00366
Opus 5 $0.00009 $0.00183
Sonnet 5 $0.00004 $0.00073
Haiku 4.5 $0.00002 $0.00037

Measured 3d ago against content hash 1087baea8153, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

history-hygiene 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 3d 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.

Origin

Copies of this mod

8 near-identical copies found in the catalogue:

.squad/templates/skills/history-hygiene/SKILL.md · 37 lines

What it actually says

Context

History files (.md files tracking decisions, spawns, outcomes) are read cold by future agents. Stale or incorrect entries poison decision-making downstream. The Kobayashi incident proved this: history said "Brady decided v0.6.0" when Brady had reversed that to v0.8.17. Future spawns read the wrong truth and repeated the mistake.

Patterns

  • Record the final outcome, not the initial request.
  • Wait for confirmation before writing to history — don't log intermediate states.
  • If a decision reverses, update the entry immediately — don't leave stale data.
  • One read = one truth. A future agent should never need to cross-reference other files to understand what actually happened.

Examples

Correct:

  • "Migration target: v0.8.17 (initially discussed as v0.6.0, corrected by Brady)"
  • "Reverted to Node 18 per Brady's explicit request on 2024-01-15"

Incorrect:

  • "Brady directed v0.6.0" (when later reversed)
  • Recording what was requested instead of what actually happened
  • Logging entries before outcome is confirmed

Anti-Patterns

  • Writing intermediate or "for now" states to disk
  • Attributing decisions without confirming final direction
  • Treating history like a draft — history is the source of truth
  • Assuming readers will cross-reference or verify; they won't
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. 3d ago First seen · 37 lines · 18 tokens per session scan A 1087baea8153

Subscribe to this mod's changes

history-hygiene is a skill published in the GitHub repository github/gh-aw (5,108 stars, last pushed today), licensed MIT. It adds 18 tokens to every session and 366 once invoked, about $0.0001 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 2026-09-03.