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.
npx agentmods add instructions/softinio/nix-config/claude-mdgit clone --depth 1 https://github.com/softinio/nix-configWrote 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/softinio/nix-config/claude-md)<a href="https://agentmods.dev/instructions/softinio/nix-config/claude-md"><img src="https://agentmods.dev/badge/instructions/softinio/nix-config/claude-md.svg" alt="Measured on agentmods" 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 | $0.02344 | $0.02344 |
| Opus 5 | $0.01172 | $0.01172 |
| Sonnet 5 | $0.00469 | $0.00469 |
| Haiku 4.5 | $0.00234 | $0.00234 |
Grade C, and why
nix-config CLAUDE.md scanned grade C 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 6d 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.
Reaches for credential fileshighPrivilege escalation
SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.
gitSigningKey = "~/.ssh/id_ed25519.pub"; # SSH pubkey for git+jj commit signing (null disables signing) How it starts
The opening of the file, as written. The whole thing — 209 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.
Overview
This is a nix-darwin and home-manager configuration for managing macOS systems declaratively. The configuration uses Nix flakes and manages both system-level packages (via nix-darwin) and user-level packages and dotfiles (via home-manager).
Supports both Apple Silicon (aarch64-darwin) and Intel (x86_64-darwin) Macs, with multi-user support for shared machines.
Architecture
Flake Structure
The repository follows a modular architecture:
flake.nix: Entry point defining inputs (nixpkgs, nix-darwin, home-manager, nixvim, herdr) and outputs. UsesmkDarwinConfighelper function to generate machine configurations. Threadshostnameto home-manager viaextraSpecialArgs.home.nix: Main home-manager entry point. Imports the program modules,packages.nix, andlocal-options.nix; sets the unfree allowlist (allowUnfreePredicate),stateVersion, andsessionVariables; and exposes shared module args (theme). It no longer holds the package list or inline program config.packages.nix: User packages (home.packages), grouped by domain (languages, language servers, formatters, vcs, cli tools, etc.).theme.nix: Shared appearance settings (currently the monospacefontFamily), passed to every module as thethemeargument.local-options.nix: Declares repo-local module options underconfig.local.*(e.g. per-editoruseNixPackagetoggles).users/*.nix: User profile files containing personal settings (gitignored to keep private).programs/default.nix: List of program module imports (each program has its own subdirectory withdefault.nix).programs/*/default.nix: Individual program configurations (fish, git, jujutsu, ghostty, nixvim, zed, etc.). Can access theuserandthemearguments. Trivialenable = trueprograms are grouped inprograms/cli-tools/default.nix.
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.
- 6d ago First seen · 209 lines · 2,344 tokens per session scan C 3fa0379f2b3d
nix-config CLAUDE.md is an instructions file published in the GitHub repository softinio/nix-config (11 stars, last pushed 21d ago), licensed MIT. It adds 2,344 tokens to every session, about $0.0117 per session on Opus 5. A static security scan graded it C with 1 finding (reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
hoenn AGENTS.md
AGENTS.md instructions for alyraffauf/hoenn, covering work in hoenn, check a change, deploy deliberately and keep secrets out of git.
nix-config AGENTS.md
AGENTS.md instructions for dliberalesso/nix-config, covering agent instructions for nix-config, build/lint/test commands, architecture guidance, architecture and common patterns.
nxv AGENTS.md
Instructions for utensils/nxv, covering agents.md, project overview, development environment, build commands and nix flake outputs.
NixKits AGENTS.md
AGENTS.md instructions for Kihara777/NixKits, covering agents.md, 访问控制, 初次启动, 语言要求 and 项目定位.
rigup.nix AGENTS.md
AGENTS.md instructions for YPares/rigup.nix, a project described as: AI agents and Nix: parametrable skills/instructions and tools, packaged together in a reproducible and modular fashion.
dotfiles AGENTS.md
AGENTS.md instructions for ahonn/dotfiles, covering agents.md, essential commands, apply configuration (workstation - primary dev machine), apply configuration (homelab - mac mini server) and update flake inputs.