lagune: Instructions file for Claude Code

CLAUDE.md

lagune CLAUDE.md is an instructions file for Claude Code from wellwelwel/lagune. It costs 2,619 tokens per session, scanned A, original, MIT.

Project instructions for Lagune, a security-focused development workflow that uses an AI assistant to harden software against problems such as leaked secrets and missing access checks.

In plain words
What is it for?
Understanding the security-hardening workspace and carrying out code reviews, fixes, and verification within its documented defensive process.
Why use it?
They explain the project's defensive purpose and direct contributors to the right guidance for architecture, engineering practices, and writing.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md.

This is wellwelwel/lagune's own configuration. It tells Claude Code how to work on lagune itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything lagune configures →

Reuse

Borrowing it

Nothing to install: this file belongs to wellwelwel/lagune. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/wellwelwel/lagune/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/wellwelwel/lagune

Made for: Claude Code.

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.

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README.md
[![agentmods](https://agentmods.dev/badge/instructions/wellwelwel/lagune/claude-md.svg)](https://agentmods.dev/instructions/wellwelwel/lagune/claude-md)
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<a href="https://agentmods.dev/instructions/wellwelwel/lagune/claude-md"><img src="https://agentmods.dev/badge/instructions/wellwelwel/lagune/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,619 This file is loaded in full into every session.
When invoked 2,619 The same file — it is already loaded in full.
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 $0.02619 $0.02619
Opus 5 $0.01309 $0.01309
Sonnet 5 $0.00524 $0.00524
Haiku 4.5 $0.00262 $0.00262

Measured 8d ago against content hash 90bac24c7a62, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

lagune CLAUDE.md 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 8d 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.

CLAUDE.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SDH (Security-Driven Hardening): Lagune

This file orients any AI agent (and human) working in this repository. Read it fully before making changes. It describes what Lagune is, who it is for, how it is built, and how to work in this codebase. For the file/folder layout and concrete structure, invoke the internal /architecture skill, for the toolchain, code conventions, and build path, the /engineering skill, and for the language conventions and how to write Lagune's prose, the /writer skill.


1. What this workspace is

This workspace is the development environment for Lagune.

Lagune is the practice of Security-Driven Hardening (SDH): a structured, AI-driven security workflow. Lagune turns a codebase into a more secure one, driving the work from a spec the agent runs rather than from ad-hoc fixes.

The project stands in the tradition of Blue Teams: the defenders in security. Lagune is about defense, hardening, and verification, never offense.

The problem it exists to solve

Software is increasingly shipped by people, and AI agents, who cannot reliably recognize an insecure pattern: a leaked secret, a missing authorization check, an injectable query. AI coding assistants made this acute by letting non-developers ship real software, but the gap is broader than any one audience. Most projects never get a security pass that is specific to what they actually do. The ecosystem becomes more fragile with every "it works, ship it" moment.

Lagune's mission is to put a defensive, security-first workflow within reach of any user, by making the AI agent do the heavy lifting: detecting what a system actually is, and guiding it toward the security practices that matter for that system, in a safe-by-default way.

What Lagune actually ships

Lagune is a collection of templates and agent commands, not a heavy framework. Its value is the workflow the AI agent runs: detecting what the system actually does (login, uploads, payments, and so on), mapping the vulnerabilities that matter for that context, then proposing, applying, and validating the right fixes. The context detection is what makes the rest specific instead of generic.

Read the full file on GitHub · 96 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. 8d ago First seen · 96 lines · 2,619 tokens per session scan A 90bac24c7a62

Subscribe to this mod's changes

lagune CLAUDE.md is an instructions file published in the GitHub repository wellwelwel/lagune (147 stars, last pushed 8d ago), licensed MIT. It adds 2,619 tokens to every session, about $0.0131 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 2026-08-30.

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