agentmods.dev

Nix Packaging

Nix Packaging is a skill for Claude Code from breakds/claude.bds. It costs 14 tokens per session (386 once invoked), scanned A, original, MIT.

A guide for packaging software with Nix. Nix is a system for describing software, its dependencies, and how it is built in a repeatable way.

In plain words
What is it for?
It helps package software from the current project or an external repository, update versions, add packages to a Nix flake, and test builds.
Why use it?
It removes much of the guesswork involved in creating or updating package definitions. It also explains how to check builds and update source hashes when software changes.

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 2 3mo ago A scan 14 tokens original MIT
View the source file 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.

agentmods
npx agentmods add skills/breakds/claude.bds/nix-packaging
Any agent
npx skills add breakds/claude.bds --skill nix-packaging
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 Packaging

README.md
[![agentmods](https://agentmods.dev/badge/skills/breakds/claude.bds/nix-packaging.svg)](https://agentmods.dev/skills/breakds/claude.bds/nix-packaging)
Your own site
<a href="https://agentmods.dev/skills/breakds/claude.bds/nix-packaging"><img src="https://agentmods.dev/badge/skills/breakds/claude.bds/nix-packaging.svg" alt="Measured on agentmods" height="20"></a>
Per session 14 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 386 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00014 $0.00386
Opus 5 $0.00007 $0.00193
Sonnet 5 $0.00003 $0.00077
Haiku 4.5 $0.00001 $0.00039

Measured 6d ago against content hash 150c14e2ff30, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

Nix Packaging 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 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.

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-packaging/SKILL.md · 41 lines

What it actually says

Overview

Create new Nix packages or update existing ones, with language-specific examples and guidance.

Workflow: Creating a New Package

  1. Identify the software source: internal to this repo or external (e.g., a GitHub repository).
  2. Determine the programming language(s) used.
  3. Analyze the software structure (build system, dependencies, configuration files).
  4. Create the package following language-specific guidance below.
  5. Optionally, integrate the package into the current project (e.g., add to overlay and expose via packages in flake.nix).
  6. Test iteratively: run nix build .#<package-name>, read errors, fix issues, and rebuild until successful.

Workflow: Updating an Existing Package

Typically, update the version and source fetching attributes (e.g., fetchFromGitHub). The hash field must also be updated using one of these methods:

Method 1: Calculate the new hash directly

# Get the hash
nix-prefetch-url --type sha256 --unpack https://github.com/owner/repo/archive/refs/tags/v<NEW_VERSION>.tar.gz
# Convert to SRI format
nix hash convert --hash-algo sha256 <old-hash>

Method 2: Let Nix tell you the hash Set hash = ""; and run the build. The error message will display the correct hash.

For language-specific update steps, see the references below.

Language-Specific Packaging Skills

Files

What ships with it

11 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. 6d ago First seen · 41 lines · 14 tokens per session scan A 150c14e2ff30

Subscribe to this mod's changes

Nix Packaging is a skill published in the GitHub repository breakds/claude.bds (2 stars, last pushed 3mo ago), licensed MIT. It adds 14 tokens to every session and 386 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.

DevOps and cloud
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