context-hygiene

context-hygiene is a cursor rule for Cursor from b-fontaine/devoxx-2026. It costs 246 tokens per session, scanned A, original, MIT.

A set of rules for keeping only the information needed for the current coding task in an agent's working context.

In plain words
What is it for?
Use it to guide targeted file reading, starting with specifications and interfaces, implementing within one architecture layer, and checking changes with tests and linting.
Why use it?
It reduces unnecessary exploration and helps prevent repeated fixes or architecture decisions that conflict with the project’s established patterns.

Cursor rule for Cursor

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 rules/b-fontaine/devoxx-2026/context-hygiene
Clone the repo
git clone --depth 1 https://github.com/b-fontaine/devoxx-2026

Made for: Cursor.

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 context-hygiene

README.md
[![agentmods](https://agentmods.dev/badge/rules/b-fontaine/devoxx-2026/context-hygiene.svg)](https://agentmods.dev/rules/b-fontaine/devoxx-2026/context-hygiene)
Your own site
<a href="https://agentmods.dev/rules/b-fontaine/devoxx-2026/context-hygiene"><img src="https://agentmods.dev/badge/rules/b-fontaine/devoxx-2026/context-hygiene.svg" alt="Measured on agentmods" height="20"></a>
Per session 246 This file is loaded in full into every session.
When invoked 246 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00246 $0.00246
Opus 5 $0.00123 $0.00123
Sonnet 5 $0.00049 $0.00049
Haiku 4.5 $0.00025 $0.00025

Measured 4d ago against content hash 53b231f21849, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

context-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 4d 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.

.cursor/rules/context-hygiene.mdc · 26 lines

What it actually says

Hygiène de contexte

Principes

  • Une session = une tâche = une couche architecturale
  • Ne lis que les fichiers nécessaires à la tâche en cours
  • Préfère lire un fichier .feature ou un trait/interface plutôt que toute l'implémentation
  • Quand tu ne sais pas où est quelque chose, utilise grep ciblé plutôt que de lire l'arborescence entière

Workflow recommandé

  1. Lis le fichier de spec/test concerné en premier
  2. Lis les interfaces/traits du domain
  3. Implémente dans une seule couche
  4. Vérifie (test + lint)
  5. Si la tâche suivante est dans une autre couche, propose un résumé des décisions avant de continuer

Signaux d'alerte

  • Si tu as lu plus de 10 fichiers sans produire de code : tu explores trop
  • Si tu répètes une correction déjà faite : le contexte est probablement saturé
  • Si tu proposes un pattern différent de celui établi : relis le CLAUDE.md/AGENTS.md
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. 4d ago First seen · 26 lines · 246 tokens per session scan A 53b231f21849

Subscribe to this mod's changes

context-hygiene is a cursor rule published in the GitHub repository b-fontaine/devoxx-2026 (5 stars, last pushed 4mo ago), licensed MIT. It adds 246 tokens to every session, about $0.0012 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.