js-package-manager

js-package-manager is a cursor rule for Cursor from kwami-labs/kwami. It costs 255 tokens per session, scanned A, original, Apache-2.0.

A repository rule for choosing Bun or pnpm, JavaScript and TypeScript package managers, instead of npm. It also defines how installs, scripts, and continuous-integration checks should run.

In plain words
What is it for?
It guides dependency installation, project scripts, test and build commands, and CI setup based on the lockfile found in the repository.
Why use it?
It prevents developers and automated builds from using different package managers or ignoring the repository’s lockfile, which can produce inconsistent dependencies.

Cursor rule for Cursor

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 rules/kwami-labs/kwami/js-package-manager
Clone the repo
git clone --depth 1 https://github.com/kwami-labs/kwami

Made for: Cursor.

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 js-package-manager

README.md
[![agentmods](https://agentmods.dev/badge/rules/kwami-labs/kwami/js-package-manager.svg)](https://agentmods.dev/rules/kwami-labs/kwami/js-package-manager)
Your own site
<a href="https://agentmods.dev/rules/kwami-labs/kwami/js-package-manager"><img src="https://agentmods.dev/badge/rules/kwami-labs/kwami/js-package-manager.svg" alt="Measured on agentmods" height="20"></a>
Per session 255 This file is loaded in full into every session.
When invoked 255 The same file — it is already loaded in full.
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 $0.00255 $0.00255
Opus 5 $0.00128 $0.00128
Sonnet 5 $0.00051 $0.00051
Haiku 4.5 $0.00026 $0.00026

Measured 3d ago against content hash 8d866d297769, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

js-package-manager 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.

.cursor/rules/js-package-manager.mdc · 36 lines

What it actually says

JS package manager

Never default to npm for install, scripts, or CI in this repo.

Detection (pick one)

  1. bun.lock / bun.lockbbun
  2. pnpm-lock.yaml / pnpm-workspace.yamlpnpm
  3. Otherwise → pnpm (default)

This repo uses pnpm (pnpm-lock.yaml).

Do / don't

# ✅
pnpm install --frozen-lockfile
pnpm lint && pnpm typecheck && pnpm test:run && pnpm build

# ❌
npm ci
npm install
npm run …

CI

  • Use pnpm/action-setup (or bun’s setup action) before actions/setup-node
  • Set cache: "pnpm" (or "bun") — never cache: "npm" unless only package-lock.json exists
  • Install with pnpm install --frozen-lockfile (or bun install --frozen-lockfile)
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 · 36 lines · 255 tokens per session scan A 8d866d297769

Subscribe to this mod's changes

js-package-manager is a cursor rule published in the GitHub repository kwami-labs/kwami (46 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 255 tokens to every session, about $0.0013 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.