check

check is a command for coding agents from joshsymonds/nix-config. It costs 7 tokens per session (296 once invoked), scanned A, original, MIT.

A code-quality command that runs the project's available checks and fixes the problems it finds.

In plain words
What is it for?
Use it before finishing work to find and repair style issues, test failures, build errors, type problems, formatting errors, and security warnings.
Why use it?
It brings linting, tests, builds, formatting, and security checks into one workflow, then repeats validation until the checks pass.

Command

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 commands/joshsymonds/nix-config/check
Clone the repo
git clone --depth 1 https://github.com/joshsymonds/nix-config

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 check

README.md
[![agentmods](https://agentmods.dev/badge/commands/joshsymonds/nix-config/check.svg)](https://agentmods.dev/commands/joshsymonds/nix-config/check)
Your own site
<a href="https://agentmods.dev/commands/joshsymonds/nix-config/check"><img src="https://agentmods.dev/badge/commands/joshsymonds/nix-config/check.svg" alt="Measured on agentmods" height="20"></a>
Per session 7 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 296 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 $0.00007 $0.00296
Opus 5 $0.00003 $0.00148
Sonnet 5 $0.00001 $0.00059
Haiku 4.5 $0.00001 $0.00030

Measured 5d ago against content hash df519b377ef2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

check 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 5d 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.

home-manager/claude-code/commands/check.md · 44 lines

What it actually says

Code Quality Check

Fix all issues found during quality verification. Do not just report problems.

Workflow

  1. Identify - Run all validation commands
  2. Fix - Address every issue found
  3. Verify - Re-run until all checks pass

Validation Commands

Find and run all applicable commands:

  • Lint: make lint, golangci-lint run, npm run lint, ruff check
  • Test: make test, go test ./..., npm test, pytest
  • Build: make build, go build ./..., npm run build
  • Format: gofmt, prettier, black
  • Security: gosec, npm audit, bandit

Parallel Fixing Strategy

When multiple issues exist, spawn agents to fix in parallel:

Agent 1: Fix linting issues in module A
Agent 2: Fix test failures
Agent 3: Fix type errors

Go-Specific Standards

  • Use concrete types, not interface{}
  • Wrap errors with context
  • Add godoc comments
  • Use channels for synchronization
  • No time.Sleep() for coordination

Success Criteria

All validation commands pass with zero warnings or errors.

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. 5d ago First seen · 44 lines · 7 tokens per session scan A df519b377ef2

Subscribe to this mod's changes

check is a command published in the GitHub repository joshsymonds/nix-config (835 stars, last pushed 8d ago), licensed MIT. It adds 7 tokens to every session and 296 once invoked, about $0.0000 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.