Borrowing it
Nothing to install: this file belongs to Univers42/hellish. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Univers42/hellish/main/CLAUDE.mdgit clone --depth 1 https://github.com/Univers42/hellishWrote 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.
[](https://agentmods.dev/instructions/univers42/hellish/claude-md)<a href="https://agentmods.dev/instructions/univers42/hellish/claude-md"><img src="https://agentmods.dev/badge/instructions/univers42/hellish/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/univers42/hellish/claude-md"><img src="https://agentmods.dev/badge/instructions/univers42/hellish/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01976 | $0.01976 |
| Opus 5.5 | $0.00790 | $0.00790 |
| Sonnet 5.5 | $0.00395 | $0.00395 |
| Haiku 4.5 | $0.00198 | $0.00198 |
Grade B, and why
hellish CLAUDE.md 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 12d 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 for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
- The tester `chmod 000`s `tests/test_files/invalid_permission`. If a run is interrupted, `chmod 755` it before git operations. How it starts
The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
hellish is a from-scratch POSIX(+bashisms, + an opt-in zsh dialect) shell in C, written as a 42 project. Its behaviour is defined by diffing against a pinned bash 5.3.9 (bash --posix) and, for the zsh dialect, a pinned zsh 5.9. In-depth docs: DEV_DOC.md, CONTRIBUTING.md, and src/<module>/README.md for each module.
Setup
- Submodules are required:
vendor/libft(libft + theft_mallocallocator) andvendor/scripts(dev tooling). If the build can't find libft, rungit submodule update --init --recursive. - Build the oracles once:
make oracle(→~/bash-5.3.9) andmake zsh-oracle(→~/zsh-5.9). The golden suite compares against these, not the system bash. makewith no target prints the help page, which lists every target with a description.
Build
| Command | Result |
|---|---|
make all |
MODE=debug: -O0 -g3, ASan+LSan, libc malloc (SAFE=1) → build/bin/hellish |
make OPT=1 all / MODE=release |
-O3 -flto, ft_malloc (SAFE=0), no sanitizers |
MODE=relwithdebinfo |
-O2 -g, ft_malloc |
make re / make re OPT=1 |
full rebuild; both must build cleanly before a PR |
-Wall -Wextra -Werror: a warning fails the build. Add flags withEXTRA_CFLAGS=…. PassingCFLAGS=…replaces the whole flag set.- Each mode/SAFE combination has its own object dir (
build/obj-<mode>-<alloc>), but they all link to the same binary path. - Sources are found with
find src(excludingsrc/platform/), so a new.cfile needs no Makefile edit. Onlysrc/platform/$(TARGET)/(currentlyposix) is compiled in. Platform-specific code goes in per-file implementations there, not in#ifdefs. - Debug knobs:
--debug=lexer|parser|ast,HELLISH_ALLOC_STATS=1(live bytes at exit, the leak oracle onSAFE=0),HELLISH_BANNER=0,HELLISH_NO_UPDATE_CHECK=1.
Test
A green make test alone isn't enough. The test layers are:
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.
- 12d ago First seen · 78 lines · 1,976 tokens per session scan B 6b20c69305a2
hellish CLAUDE.md is an instructions file published in the GitHub repository Univers42/hellish (54 stars, last pushed 6d ago), licensed MIT. It adds 1,976 tokens to every session, about $0.0079 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-18.
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