MassGen CLAUDE.md

MassGen CLAUDE.md is an instructions file for coding agents from massgen/MassGen. It costs 4,568 tokens per session, scanned A, original, no licence file.

Repository-specific instructions for coding assistants working on MassGen. They cover instruction files, OpenSpec planning, keeping guidance files consistent, and debugging assumptions.

In plain words
What is it for?
Making code changes, preparing plans, keeping CLAUDE.md and related instructions aligned, and investigating MassGen issues.
Why use it?
They help assistants plan and debug changes consistently with the project's development rules.

Instructions file

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 instructions/massgen/massgen/claude-md
Clone the repo
git clone --depth 1 https://github.com/massgen/MassGen

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 MassGen CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/massgen/massgen/claude-md.svg)](https://agentmods.dev/instructions/massgen/massgen/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/massgen/massgen/claude-md"><img src="https://agentmods.dev/badge/instructions/massgen/massgen/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 4,568 This file is loaded in full into every session.
When invoked 4,568 The same file — it is already loaded in full.
Security scan A 0 findings. 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 $0.04568 $0.04568
Opus 5 $0.02284 $0.02284
Sonnet 5 $0.00914 $0.00914
Haiku 4.5 $0.00457 $0.00457

Measured 4d ago against content hash aa50fd1e30f1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

MassGen 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 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.

CLAUDE.md · 342 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 4d ago First seen · 342 lines · 4,568 tokens per session scan A aa50fd1e30f1

Subscribe to this mod's changes

MassGen CLAUDE.md is an instructions file published in the GitHub repository massgen/MassGen (1,125 stars, last pushed 2mo ago), with no licence file. It adds 4,568 tokens to every session, about $0.0228 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.