Borrowing it
Nothing to install: this file belongs to FilipNowakowicz/nixos-config. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/FilipNowakowicz/nixos-config/main/.agents/skills/nix-verification-loop/SKILL.mdgit clone --depth 1 https://github.com/FilipNowakowicz/nixos-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/skills/filipnowakowicz/nixos-config/nix-verification-loop)<a href="https://agentmods.dev/skills/filipnowakowicz/nixos-config/nix-verification-loop"><img src="https://agentmods.dev/badge/skills/filipnowakowicz/nixos-config/nix-verification-loop/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.
<a href="https://agentmods.dev/skills/filipnowakowicz/nixos-config/nix-verification-loop"><img src="https://agentmods.dev/badge/skills/filipnowakowicz/nixos-config/nix-verification-loop.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00029 | $0.02487 |
| Opus 5 | $0.00015 | $0.01243 |
| Sonnet 5 | $0.00006 | $0.00497 |
| Haiku 4.5 | $0.00003 | $0.00249 |
Grade B, and why
nix-verification-loop scanned grade B 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 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
the new services absent from the running generation. Confirm sudo is usable How it starts
The opening of the file, as written. The whole thing — 155 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Nix Verification Loop
Use this workflow whenever editing Nix, shell scripts, host definitions, tests, packages, deploy wiring, secrets boundaries, or generated data in this repo.
Workflow
- Identify the touched surface:
- Flake/module wiring: start with
bash scripts/validate.sh flake-eval. - Shared modules/profiles/lib helpers: add
bash scripts/validate.sh light. - A single host: run
bash scripts/validate.sh host <name>when closure risk matters. - Package outputs: run
bash scripts/validate.sh package <name>orpackage all. - Profile behavior: run
bash scripts/validate.sh profile-test <name>. - Homeserver routing: run
bash scripts/validate.sh smoke-homeserver-gcpwhen endpoint behavior changes. - Markdown-only repo docs: run
bash scripts/validate.sh docs.
- Flake/module wiring: start with
- If new files are created for a Nix flake check or build, stage them before expecting Nix to see them.
- Prefer the narrow check first, then widen only when the touched surface justifies it.
- Report any skipped validation explicitly with the reason.
- For a wider tier (
hosts,package all,heavy,cve-reports), consider running it via a subagent that redirects output to a file and returns only the exit status and tail — this keeps the noisy build entirely out of the main session's transcript instead of relying on truncation alone.
Guardrails
- Do not run deploy commands unless the user asked for deployment or the task explicitly requires landing live host state.
- Treat
deploy-rssilence in non-interactive sessions as a known behavior; if necessary, fall back to closure build/copy/switch instructions fromCLAUDE.md. - Never edit encrypted secrets directly. Use
sops. nix develop -c <tool>/nix develop --command <tool>now pass through<tool>'s stdout and exit status: the default devShell shell hook only execs zsh for interactive sessions ($-containingi), not for-cinvocations. Prefer tools already available in the current shell directly when possible, butnix develop -c <cmd>is valid proof a command ran.- When backgrounding a validation command, join every step on one logical line
with
&&/;(or a single quotedbash -c '...') — never rely on a literal newline between top-level statements. A backgrounded multi-line command can collapse onto one pipeline, e.g. turningnix fmt FILE | tail -5+ a followinggit addline intotail -5 git add FILE && git commit, which hangstailforever on an open pipe with empty output. Avoid pipingnix develop -c <cmd>throughtail/headin the background for the same reason; run such commands in the foreground or redirect to a file instead.
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.
- 9d ago First seen · 155 lines · 29 tokens per session scan B 70ecaa8bb01d
nix-verification-loop is a skill published in the GitHub repository FilipNowakowicz/nixos-config (5 stars, last pushed 5d ago), licensed MIT. It adds 29 tokens to every session and 2,487 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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