agentmods.dev

nix-scaffolding

nix-scaffolding is a skill for Claude Code from breakds/claude.bds. It costs 24 tokens per session (951 once invoked), scanned A, original, MIT.

A guide for creating a new project with a Nix flake and development shell. A Nix flake records project setup, while a development shell provides the tools and dependencies used for development.

In plain words
What is it for?
It helps scaffold Python, Python with machine learning, Rust, and web projects, including dependencies, system packages, environment variables, shell commands, and a pinned Nix package set.
Why use it?
It removes repetitive setup work and keeps the development environment defined in the project. It also helps configure language-specific dependencies and startup commands.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the bds-dev plugin — 2 skills, 3 commands shipped together

not rated 2repo 3mo ago A scan 24 tokens original MIT

Good fit It helps scaffold Python, Python with machine learning, Rust, and web projects, including dependencies, system packages, environment variables, shell commands, and a pinned Nix package set.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/breakds/claude.bds/nix-scaffolding
View source ↗ breakds/claude.bds
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.

Any agent
npx skills add breakds/claude.bds --skill nix-scaffolding
Clone the repo
git clone --depth 1 https://github.com/breakds/claude.bds

Made for: Claude Code.

Or install bds-dev, the plugin that ships this one along with the rest of its 2 skills, 3 commands.

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 nix-scaffolding

README.md
[![agentmods](https://agentmods.dev/badge/skills/breakds/claude.bds/nix-scaffolding/github.svg)](https://agentmods.dev/skills/breakds/claude.bds/nix-scaffolding)
Your own site
<a href="https://agentmods.dev/skills/breakds/claude.bds/nix-scaffolding"><img src="https://agentmods.dev/badge/skills/breakds/claude.bds/nix-scaffolding/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.

agentmods 80×15 button for nix-scaffolding

Your own site · 80×15
<a href="https://agentmods.dev/skills/breakds/claude.bds/nix-scaffolding"><img src="https://agentmods.dev/badge/skills/breakds/claude.bds/nix-scaffolding.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 951 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00024 $0.00951
Opus 5 $0.00012 $0.00476
Sonnet 5 $0.00005 $0.00190
Haiku 4.5 $0.00002 $0.00095

Measured 9d ago against content hash 2eef5a97c14d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

nix-scaffolding 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 9d 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.

bds-dev/skills/nix-scaffolding/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Nix Project Scaffolding

Create new projects with flake.nix and devshell for Python, Rust, or webapp stacks.

Workflow

  1. Gather basic info:

    • Project name (used for directory and shell name)
    • Short description (for flake description)
    • Project type: Python / Python+ML / Rust / Webapp

  2. Gather project-specific details:

    • Python/Python+ML: Initial Python dependencies to include (e.g., pandas, pytest, fastapi)
    • Rust: Additional system dependencies for buildInputs (e.g., libva, glib.dev)
    • Webapp: Any additional tools beyond Node.js + pnpm
    • All: Custom shellHook commands, environment variables, or special configurations

  3. Ask for nixpkgs pin:

    • Ask user which nixpkgs commit to pin in flake.lock
    • User may provide a commit hash or reference another project's lock

  4. Create and customize project:

    • Create project directory
    • Copy appropriate template from templates/
    • Replace {{PROJECT_NAME}} and {{PROJECT_DESCRIPTION}} placeholders
    • Customize based on gathered details:
      • Add specified dependencies to packages list
      • Add any custom buildInputs or environment variables
      • Modify shellHook if needed
    • Run git init
    • Run nix flake lock --override-input nixpkgs github:NixOS/nixpkgs/<commit>

Templates

Template Use when
basic-python Pure Python projects without ML/CUDA needs
basic-python-ml ML/robotics projects needing CUDA and ml-pkgs overlay
basic-rust Rust projects (uses crane with full checks)
basic-webapp Frontend apps with Node.js + pnpm
pyo3-python Python library with Rust backend via PyO3/maturin
esp32 ESP32 embedded projects with ESP-IDF (C/C++)

Template Structure

All templates create:

<project>/
  flake.nix           # flake-parts based
  .envrc              # direnv integration (watch_dir nix, use flake)
  nix/
    development.nix   # devShell definition

Read the full file on GitHub · 98 lines

Files

What ships with it

24 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 9d ago First seen · 98 lines · 24 tokens per session scan A 2eef5a97c14d

Subscribe to this mod's changes

nix-scaffolding is a skill published in the GitHub repository breakds/claude.bds (2 stars, last pushed 3mo ago), licensed MIT. It adds 24 tokens to every session and 951 once invoked, about $0.0001 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.

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