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/grigio/docker-nixuser/agents-mdgit clone --depth 1 https://github.com/grigio/docker-nixuserWhat 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 | $0.01391 | $0.01391 |
| Opus 5 | $0.00696 | $0.00696 |
| Sonnet 5 | $0.00278 | $0.00278 |
| Haiku 4.5 | $0.00139 | $0.00139 |
Grade A, and why
docker-nixuser 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Development Guide
NOTE: Keep it updated with the most useful non-trivial dev info. Keep it minimal.
CI Publishing (CRITICAL)
The publish job runs on v* tag push (push: tags: ['v*']), not on push to master. Push to master only runs build (test, no ghcr.io push). To publish:
git tag vX.Y.Z && git push origin vX.Y.Z
Note: Uses push: tags trigger, not create event — git push --tags triggers it reliably.
The tag triggers both build and publish jobs. The publish job builds amd64 + arm64, pushes platform-specific images, then creates multi-arch manifests (version + latest).
Multi-Platform CI Builds
The CI workflow builds Docker images for:
linux/amd64(x86_64)linux/arm64(aarch64) — built via Nix--system aarch64-linuxwith QEMU emulation
Multi-platform images use Docker manifests. Platform-specific images are tagged as:
ghcr.io/grigio/docker-nixuser:TAG-amd64ghcr.io/grigio/docker-nixuser:TAG-arm64
Arm64 builds use docker/setup-qemu-action for QEMU binfmt registration, allowing Nix to
cross-build for aarch64-linux on amd64 runners via nix build .#default --system aarch64-linux.
Arm64 testing in CI uses docker run --platform linux/arm64 (relies on QEMU binfmt from
docker/setup-qemu-action for transparent emulation).
Flake Auto-Update
The flake-update-check.yml workflow runs weekly (Sunday 2 AM UTC) and:
- Checks if
flake.lockis up to date - Updates GitHub status check
- Automatically creates a pull request if updates are available
Docker Image
The project creates a Docker image with Nix package manager running as non-root user nixuser.
Build
nix --extra-experimental-features 'nix-command flakes' build .#default
Load Image
docker load < result
Run Container
docker run -it nix-nixuser:latest
Test Nix Installation
docker run --rm nix-nixuser:latest sh -c 'whoami && nix profile add nixpkgs#hello && hello'
Expected output:
nixuser
Hello, world!
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.
- 2d ago First seen · 117 lines · 1,391 tokens per session scan A d325f10edfa1
docker-nixuser AGENTS.md is an instructions file published in the GitHub repository grigio/docker-nixuser (22 stars, last pushed 1mo ago), licensed MIT. It adds 1,391 tokens to every session, about $0.0070 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.
Other instructions, from other repositories
agent-box AGENTS.md
Instructions for 0xferrous/agent-box, covering pre commit, image, returns: /nix/store/ -source, wrappers and portal adr.
microsandbox AGENTS.md
AGENTS.md instructions for superradcompany/microsandbox, covering agents.md, scope, project map, design principles and backward compatibility review.
sandboxd AGENTS.md
Instructions for tastyeffectco/sandboxd, covering agents.md — operating sandboxd, what this is, prerequisites, install and core api.
greywall CLAUDE.md
Instructions for GreyhavenHQ/greywall, covering greywall, build & run, test, lint & format and project structure.
MultiGen CLAUDE.md
Instructions for lingyuanli/MultiGen, covering claude.md, architecture, development commands, full stack (docker) and api (local).
agentbox CLAUDE.md
Instructions for madarco/agentbox, covering agentbox — context for claude code, architecture overview, important notes, testing / verifying and conventions.