experiments: Cursor rule for Cursor

.cursor/deprecated/typescript-esm-conventions.mdc

typescript-esm-conventions is a cursor rule for Cursor from reliverse/experiments. It costs 0 tokens per session (840 once invoked), scanned A, original, MIT.

Coding rules for TypeScript projects that use modern JavaScript modules, strict types, consistent file names, and shared type definitions. TypeScript is JavaScript with features that help catch mistakes before the code runs.

In plain words
What is it for?
Use it when writing or reviewing TypeScript files, choosing import and export patterns, naming files, or defining shared types.
Why use it?
It prevents inconsistent imports, exports, file names, and type usage across the codebase. Following one module style also makes files easier to combine and maintain.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

This is reliverse/experiments's own configuration. It tells Cursor how to work on experiments itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything experiments configures →

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { validateInput } from '../validation/mod.js'.

Reuse

Borrowing it

Nothing to install: this file belongs to reliverse/experiments. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/reliverse/experiments/main/.cursor/deprecated/typescript-esm-conventions.mdc
Clone the repo
git clone --depth 1 https://github.com/reliverse/experiments

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 typescript-esm-conventions

README.md
[![agentmods](https://agentmods.dev/badge/rules/reliverse/experiments/typescript-esm-conventions/github.svg)](https://agentmods.dev/rules/reliverse/experiments/typescript-esm-conventions)
Your own site
<a href="https://agentmods.dev/rules/reliverse/experiments/typescript-esm-conventions"><img src="https://agentmods.dev/badge/rules/reliverse/experiments/typescript-esm-conventions/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.

agentmods 80×15 button for typescript-esm-conventions

Your own site · 80×15
<a href="https://agentmods.dev/rules/reliverse/experiments/typescript-esm-conventions"><img src="https://agentmods.dev/badge/rules/reliverse/experiments/typescript-esm-conventions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 840 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00840
Opus 5.5 $0.00000 $0.00336
Sonnet 5.5 $0.00000 $0.00168
Haiku 4.5 $0.00000 $0.00084

Measured 1mo ago against content hash da0fd3153a40, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

typescript-esm-conventions 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 1mo 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/deprecated/typescript-esm-conventions.mdc · 121 lines

How it starts

The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.

TypeScript and ESM Conventions

Follow these TypeScript and ESM patterns for consistency across the Rempts codebase.

Module System

  • Always use ESM imports/exports, never CommonJS (require/module.exports)
  • Use .js extensions for all local imports (ESM requirement)
  • Prefer named exports over default exports for better tree-shaking
// ✅ Good - ESM with .js extensions for local files
import { defineCommand } from '@reliverse/rempts'
import { validateConfig } from './utils/validation.js'

// ✅ Good - Named exports
export { myFunction, MyClass }

// ❌ Avoid - CommonJS
const { defineCommand } = require('@reliverse/rempts')

// ❌ Avoid - Missing .js extension for local imports
import { helper } from './helper'

File Naming

  • Use kebab-case for all files: config-parser.ts, user-input.ts
  • Test files: my-feature.test.ts
  • Type definition files: api-types.ts
  • Never use PascalCase or camelCase for file names

Type Safety

Plugin Type Patterns

// Define store types for plugins
interface MyPluginStore {
  data: string[]
  count: number
}

// Use createPlugin with generics for type safety
const myPlugin = createPlugin<MyPluginStore>({
  name: 'my-plugin',
  store: {
    data: [],
    count: 0
  },
  beforeCommand({ store }) {
    // TypeScript knows store.data is string[]
    store.data.push('command')
  }
})

// For plugin factories with options
const myPlugin = createPlugin<Options, Store>((options) => ({
  // Plugin definition
}))

Package Development

  • Each package has its own package.json with proper ESM configuration
  • Use "type": "module" in package.json
  • Build scripts are in scripts/build.ts using Bun's bundler
  • Export types and runtime code separately when needed

Read the full file on GitHub · 121 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. 1mo ago First seen · 121 lines · 0 tokens per session scan A da0fd3153a40

Subscribe to this mod's changes

typescript-esm-conventions is a cursor rule published in the GitHub repository reliverse/experiments (117 stars, last pushed 7mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 840 tokens. 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 2026-09-01.