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

Use it before finishing work to find and repair style issues, test failures, build errors, type problems, formatting errors, and security warnings.

It brings linting, tests, builds, formatting, and security checks into one workflow, then repeats validation until the checks pass.

check — Command for Claude Code by joshsymonds/nix-config

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.

Clone the repo

git clone --depth 1 https://github.com/joshsymonds/nix-config

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/joshsymonds/nix-config/check/github.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/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/joshsymonds/nix-config/check"><img src="https://agentmods.dev/badge/commands/joshsymonds/nix-config/check.svg" alt="Reviewed on agentmods" width="80" 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. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00007	$0.00296
Opus 5.5	$0.00003	$0.00118
Sonnet 5.5	$0.00001	$0.00059
Haiku 4.5	$0.00001	$0.00030

Measured 2mo ago against content hash df519b377ef2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 2mo 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

Identify - Run all validation commands
Fix - Address every issue found
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.

2mo 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 yesterday), licensed MIT. It adds 7 tokens to every session and 296 once invoked, about $0.0000 per session on Opus 5.5. 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.

Debugging

check next to 6 commands from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
checkjoshsymonds/nix-config	Command	835	yesterday	MIT	A	7	Claude Code
qa-changesOpenHands/extensions	Command	176	yesterday	MIT	A	63	Claude Code
react-nativegetsentry/toolkit	Command	957	yesterday	none	A	0	Claude Code
auditar-cascadingluanpdd/kit-mcp	Command	5	4d ago	MIT	A	54	Claude Code
http-serviceMadAppGang/magus	Command	14	yesterday	MIT	A	27	Claude Code
doctordoncheli/don-cheli-sdd	Command	59	2mo ago	Apache-2.0	A	76	Claude Code
doctorfatihkan/badi	Command	7	1mo ago	MIT	A	0	Claude Code