nxv AGENTS.md

nxv AGENTS.md is an instructions file for Codex, OpenCode from utensils/nxv. It costs 4,039 tokens per session, scanned A, original, MIT.

Repository instructions for nxv, a Rust command-line tool and web service that finds specific versions of Nix packages by searching the history of nixpkgs, the package collection for Nix. It covers the Nix development environment and build and test commands.

In plain words
What is it for?
Use it when developing nxv, entering its reproducible Nix environment, building release or indexer versions, running the HTTP service, or testing its package lookup and database code.
Why use it?
It tells a coding agent how this project is structured and how to compile and test it, including checks that require the optional indexer feature.

Instructions file for CodexOpenCode

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/utensils/nxv/agents-md
Clone the repo
git clone --depth 1 https://github.com/utensils/nxv

Made for: Codex, OpenCode.

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 nxv AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/utensils/nxv/agents-md.svg)](https://agentmods.dev/instructions/utensils/nxv/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/utensils/nxv/agents-md"><img src="https://agentmods.dev/badge/instructions/utensils/nxv/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 4,039 This file is loaded in full into every session.
When invoked 4,039 The same file — it is already loaded in full.
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 $0.04039 $0.04039
Opus 5 $0.02020 $0.02020
Sonnet 5 $0.00808 $0.00808
Haiku 4.5 $0.00404 $0.00404

Measured 4d ago against content hash 983e2f051bdc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

nxv AGENTS.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.

AGENTS.md · 270 lines

How it starts

The opening of the file, as written. The whole thing — 270 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

This file provides guidance to AI coding agents (Claude Code, Codex, etc.) when working with code in this repository. CLAUDE.md is a symlink to this file — edit here.

Project Overview

nxv (Nix Versions) is a Rust CLI tool for quickly finding specific versions of Nix packages across nixpkgs history. It uses a pre-built SQLite index with bloom filters for fast lookups. Also provides an HTTP API server with web frontend.

Development Environment

This project uses Nix flakes with crane for reproducible builds:

nix develop          # Enter devshell with Rust toolchain
direnv allow         # Or use direnv for automatic shell activation

Build Commands

cargo build                      # Debug build
cargo build --release            # Release build
cargo build --features indexer   # Build with indexer feature
cargo run -- <args>              # Run with arguments
cargo test                       # Run default test suite (unit + integration)
cargo test --features indexer    # Include indexer tests (some #[ignore]d ones need `nix` + network)
cargo test <test_name>           # Run a single test by name
cargo test db::                  # Run tests in a specific module
cargo clippy --features indexer -- -D warnings   # Lint (matches CI; CI also runs the featureless variant)
cargo fmt                        # Format code
cargo bench                      # Run benchmarks (bloom, search, indexer)
nix flake check                  # Run all Nix checks (build, clippy, fmt, tests, a11y)

The devshell provides shortcuts for all of these (build, clippy, fmt-check, run-tests, coverage, ...). ci-local runs the exact CI sequence: fmt-check, clippy, test — all with --features indexer.

Nix Flake Outputs

nix build                        # Build nxv (user binary)
nix build .#nxv-indexer          # Build with indexer feature
nix build .#nxv-static           # Static musl build (Linux only; native arch)
nix build .#nxv-static-aarch64   # Static musl build (aarch64, cross-compiled on x86_64 Linux)
nix build .#nxv-docker           # Docker image (Linux only, use --system x86_64-linux on macOS)
nix run                          # Run nxv directly
nix run .#nxv-indexer            # Run with indexer feature

Read the full file on GitHub · 270 lines

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 · 270 lines · 4,039 tokens per session scan A 983e2f051bdc

Subscribe to this mod's changes

nxv AGENTS.md is an instructions file published in the GitHub repository utensils/nxv (136 stars, last pushed 22d ago), licensed MIT. It adds 4,039 tokens to every session, about $0.0202 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.