Bootstrap TypeScript Open-Source Package

Scaffold a production-ready TypeScript npm package using Mike's stack: Bun runtime, tsup bundler, Biome linter/formatter, Husky git hooks, and GitHub Actions for CI + npm publishing with provenance.

Philosophy

• Anti-fragile: Always run bun init first so scaffolding stays current, then overlay configs on top.
• Dual format: Every package ships both ESM and CJS with full TypeScript declarations.
• Strict by default: Strict TypeScript, Biome linting, and pre-commit hooks enforcing lint + test.
• One-command ship: Tag-triggered publishing via GitHub Actions — no manual npm publish.
• AGENTS.md: Every repo gets an AGENTS.md so AI tools understand the project immediately.

Workflow

Step 0: Confirm names

Before starting, if the user hasn't already specified:

1. npm package name — suggest a reasonable default based on the project description (e.g. the kebab-case project name) and ask the user to confirm or provide an alternative.
2. GitHub repo name — suggest the same name as the npm package and ask the user to confirm or provide an alternative.

Step 1: Initialize with Bun

mkdir <project-name> && cd <project-name>
bun init -y

Inspect what bun init produced — it scaffolds package.json, tsconfig.json, an entry point, and possibly other files. These evolve over time as Bun updates, so do not blindly overwrite them. The steps below describe which fields/settings to ensure are present; always start from what bun init gave you and adjust from there.

If bun init places an entry file at the root (e.g. index.ts), move it to src/index.ts.

Step 2: Set up directory structure

<project-name>/
├── .github/
│   └── workflows/
│       ├── ci.yml
│       └── publish.yml
├── .husky/
│   └── pre-commit
├── src/
│   ├── index.ts          # Main entry point
│   └── index.test.ts     # Tests (colocated)
├── .gitignore
├── AGENTS.md
├── biome.json
├── LICENSE
├── package.json
├── README.md
├── tsconfig.json
└── tsup.config.ts

Step 3: Install dev dependencies

bun add -d typescript tsup @biomejs/biome husky @types/bun

Step 4: Configure package.json

Start from whatever bun init generated and ensure the following fields are set. Don't drop fields that bun init added unless they conflict.

Fields to set/add (adapt name, description, repository, etc. to the specific project):

{
  "license": "MIT",
  "author": "miketromba",
  "repository": {
    "type": "git",
    "url": "https://github.com/miketromba/<package-name>.git"
  },
  "homepage": "https://github.com/miketromba/<package-name>",
  "bugs": {
    "url": "https://github.com/miketromba/<package-name>/issues"
  },
  "keywords": [],
  "type": "module",
  "main": "./dist/index.cjs",
  "module": "./dist/index.js",
  "types": "./dist/index.d.ts",
  "exports": {
    ".": {
      "import": {
        "types": "./dist/index.d.ts",
        "default": "./dist/index.js"
      },
      "require": {
        "types": "./dist/index.d.cts",
        "default": "./dist/index.cjs"
      }
    }
  },
  "files": ["dist", "README.md"],
  "scripts": {
    "build": "tsup",
    "lint": "biome check .",
    "lint:fix": "biome check --write .",
    "test": "bun test",
    "prepare": "husky"
  }
}

Key points:

• "type": "module" — ESM-first
• Dual exports map with separate import/require paths and their types conditions
• "files" controls what ships to npm — keep it minimal
• "prepare": "husky" — auto-installs hooks on bun install
• devDependencies are populated by the bun add -d step — do not hardcode versions
• Remove any bun init entry point field (e.g. "module": "index.ts") that points to a non-dist path

Step 5: Configure TypeScript

bun init generates a tsconfig.json. Keep its defaults and ensure these settings are present (add or override as needed):

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "declaration": true,
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "outDir": "dist",
    "rootDir": "src",
    "types": ["bun-types"]
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist"]
}

If bun init adds new useful fields in the future, keep them. The critical settings above must be present for dual-format builds to work.

Step 6: Configure tsup

import { defineConfig } from 'tsup'

export default defineConfig({
  entry: ['src/index.ts'],
  format: ['cjs', 'esm'],
  dts: true,
  splitting: false,
  clean: true,
  target: 'es2020',
  outDir: 'dist'
})

This produces dist/index.js (ESM), dist/index.cjs (CJS), dist/index.d.ts, and dist/index.d.cts.

Step 7: Configure Biome

{
  "$schema": "https://biomejs.dev/schemas/2.4.2/schema.json",
  "files": {
    "includes": ["**", "!dist"]
  },
  "formatter": {
    "enabled": true,
    "indentStyle": "tab",
    "indentWidth": 4,
    "lineWidth": 80
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "single",
      "semicolons": "asNeeded",
      "trailingCommas": "none",
      "arrowParentheses": "asNeeded"
    }
  }
}

Style: tabs, single quotes, no semicolons, no trailing commas, arrow parens only when needed. Add additional paths to the !dist exclude pattern if the project generates files (e.g. "!data").

Step 8: Configure .gitignore

bun init may create a .gitignore. If so, keep its contents and ensure these entries are present:

# dependencies
node_modules/

# output
dist/

# env
.env
.env.*

# caches
*.tsbuildinfo
.cache

# OS
.DS_Store

# IDE
.idea/
.vscode/

Step 9: Set up Husky pre-commit hook

bunx husky init

Then overwrite .husky/pre-commit with:

bun run lint
bun test

This enforces that every commit passes linting and tests.

Step 10: Create GitHub Actions — CI

.github/workflows/ci.yml:

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  build-and-test:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Bun
        uses: oven-sh/setup-bun@v2

      - name: Install dependencies
        run: bun install

      - name: Lint
        run: bun run lint

      - name: Build
        run: bun run build

      - name: Test
        run: bun test

Step 11: Create GitHub Actions — Publish

.github/workflows/publish.yml:

name: Publish to NPM

on:
  push:
    tags:
      - "v*"

jobs:
  publish:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      id-token: write

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Bun
        uses: oven-sh/setup-bun@v2

      - name: Setup Node
        uses: actions/setup-node@v4
        with:
          node-version: "24"

      - name: Install dependencies
        run: bun install

      - name: Lint
        run: bun run lint

      - name: Build
        run: bun run build

      - name: Test
        run: bun test

      - name: Publish to NPM
        run: npm publish --access public

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          generate_release_notes: true

The id-token: write permission enables npm provenance. Node is needed alongside Bun because npm publish handles registry auth and provenance attestation.

Trusted publishing setup: The first publish of a new package must be done manually via npm publish --access public from the local machine. After that initial publish, go to the package's settings on npmjs.com, navigate to Publishing access and configure Trusted Publishing (OIDC) for the GitHub repository and the publish.yml workflow. Once configured, no NPM_TOKEN secret is needed — the workflow authenticates automatically via GitHub's OIDC token.

Step 12: Create MIT LICENSE

Create a standard MIT license file with the copyright holder Michael Tromba and the current year.

Step 13: Create AGENTS.md

Write an AGENTS.md tailored to the project. Follow this structure:

# Agents

- **Runtime/tooling:** Bun (not Node)
- **Build:** `bun run build` — runs tsup
- **Lint:** `bun run lint` (Biome)
- **Test:** `bun test`
- **Pre-commit hook:** Husky runs lint + test automatically

## Shipping

When the user says "ship", that means: **push to remote AND publish to npm**. Do both.

1. `git push` — push commits to the remote
2. `npm version patch` (or `minor` / `major` as appropriate) — bumps version and creates a tag
3. `git push && git push --tags` — pushes the version commit and tag

The `v*` tag triggers `.github/workflows/publish.yml` which lints, builds, tests, publishes to npm with provenance, and creates a GitHub Release.

**Never skip the push + version + tag steps when asked to ship.**

Add project-specific sections as needed (source of truth, conventions, etc.).

Step 14: Create README.md

Write a README appropriate to the package. Sections to consider (not all required — use judgment based on the package's subject matter):

• Banner image and/or badges (npm version, license)
• Clear description of what the package does
• Install instructions (show multiple package managers: npm, bun, pnpm, yarn)
• Usage examples with TypeScript code
• Why use this / motivation
• Contributing guide
• License link

Step 15: Write starter source and test

src/index.ts — the main entry point with the package's public API.

src/index.test.ts — colocated tests using bun:test:

import { describe, expect, test } from 'bun:test'

Step 16: Build, lint, test, and verify

bun run build
bun run lint
bun test

Step 17: Create GitHub repo and push

If the user hasn't specified a repo name, suggest one based on the package name and ask for confirmation.

gh repo create miketromba/<repo-name> --public --source=. --remote=origin --push

This initializes git, creates the remote repo, and pushes in one step. If git is already initialized or the repo already exists, fall back to manual steps as needed.

Ship checklist

When the user says "ship":

1. git push
2. npm version patch (or minor / major)
3. git push && git push --tags

The v* tag triggers the publish workflow automatically.