check-vercel-rules

check-vercel-rules is a command for coding agents from Lykhoyda/rn-dev-agent. It costs 41 tokens per session (750 once invoked), scanned A, original, MIT.

A command that checks a project’s JavaScript and TypeScript files against Vercel Labs coding rules. It can review changed files, the whole project, or run as a continuous-integration check.

In plain words
What is it for?
Use it for manual project audits, checking edited files, creating a baseline of existing violations, or blocking non-compliant code in CI.
Why use it?
It finds rule violations before they reach review or release and can make violations fail a CI check. It also supports machine-readable report formats.

Command

Part of the rn-dev-agent plugin — 11 skills, 16 commands, 5 agents, 6 hooks shipped together

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/lykhoyda/rn-dev-agent/check-vercel-rules
Clone the repo
git clone --depth 1 https://github.com/Lykhoyda/rn-dev-agent

Or install rn-dev-agent, the plugin that ships this one along with the rest of its 11 skills, 16 commands, 5 agents, 6 hooks.

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-vercel-rules

README.md
[![agentmods](https://agentmods.dev/badge/commands/lykhoyda/rn-dev-agent/check-vercel-rules.svg)](https://agentmods.dev/commands/lykhoyda/rn-dev-agent/check-vercel-rules)
Your own site
<a href="https://agentmods.dev/commands/lykhoyda/rn-dev-agent/check-vercel-rules"><img src="https://agentmods.dev/badge/commands/lykhoyda/rn-dev-agent/check-vercel-rules.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 750 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 $0.00041 $0.00750
Opus 5 $0.00020 $0.00375
Sonnet 5 $0.00008 $0.00150
Haiku 4.5 $0.00004 $0.00075

Measured 3d ago against content hash 3846f1ec99b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

check-vercel-rules 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 3d 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.

packages/claude-plugin/commands/check-vercel-rules.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Run the Vercel rule audit: $ARGUMENTS

Why this command exists

The PostToolUse audit hook (hooks/vercel-rules-audit.sh) checks rules on single-file edits during a session. This command runs the same checker across a broader scope — the whole project, just changed files, or for CI/pre-ship gating — and emits the chosen output format.

It wraps scripts/check-vercel-rules.mjs. Same checker, three call sites:

  • PostToolUse hook (per edit, automatic)
  • This slash command (manual, project-scoped)
  • pre-ship-checker integration (CI, blocks on violations)

Modes

Argument Behavior
(none) --all walk of cwd; reports violations; exit 0
--changed [files...] Check only specified files (or stdin one-per-line)
--all Walk cwd for .tsx/.jsx/.ts/.js; max 200 files
--ci Same as --all but exits 1 on any violation (use in pre-commit/CI)
--baseline-snapshot Write current violations to baseline path; exit 0
--format hook|json|sarif Output shape (default hook)

Run

# Default: --all on cwd, hook-format output
if [[ -z "$ARGUMENTS" ]]; then
  node "${CLAUDE_PLUGIN_ROOT}/scripts/check-vercel-rules.mjs" --all
else
  node "${CLAUDE_PLUGIN_ROOT}/scripts/check-vercel-rules.mjs" $ARGUMENTS
fi

After the run

  • No violations → no output. The repo is clean against the v1.0 grep-checker subset.
  • Violations reported → each line cites a rule ID and points to the upstream rule file under third_party/vercel-labs/agent-skills/skills/... for the full explanation + fix.
  • Want to suppress legacy violations? Run /rn-dev-agent:check-vercel-rules --baseline-snapshot to snapshot the current set; subsequent runs (and the PostToolUse hook) will only report NEW violations. Critical for retrofit on existing codebases.
  • Want SARIF for GitHub code-scanning? Use --format sarif; the output conforms to SARIF 2.1.0 and uploads cleanly to the Code Scanning API.

Reference

Read the full file on GitHub · 65 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. 3d ago First seen · 65 lines · 41 tokens per session scan A 3846f1ec99b4

Subscribe to this mod's changes

check-vercel-rules is a command published in the GitHub repository Lykhoyda/rn-dev-agent (11 stars, last pushed 3d ago), licensed MIT. It adds 41 tokens to every session and 750 once invoked, about $0.0002 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.