Runtime Support

Connectum packages ship compiled JavaScript with TypeScript declarations (.d.ts) and source maps. This means no special loader or register hook is needed for any runtime -- all runtimes can import @connectum/* packages directly.

Node.js 25+

Node.js 25+ supports type stripping for your own .ts source files. Since @connectum/* packages ship compiled .js, no loader is required:

node src/index.ts

In package.json:

{
  "scripts": {
    "start": "node src/index.ts",
    "dev": "node --watch src/index.ts"
  }
}

What Packages Ship

Each @connectum/* package is built with tsup and publishes:

• Compiled .js files (ESM) -- ready to run on any ES module-capable runtime
• TypeScript declarations (.d.ts) -- full type information for IDE support and type checking
• Source maps (.js.map) -- accurate stack traces pointing to the original TypeScript source

Bun

Bun natively supports TypeScript for your own source files. Since @connectum/* packages ship compiled .js, everything works out of the box:

bun src/index.ts

In package.json:

{
  "scripts": {
    "start": "bun src/index.ts",
    "dev": "bun --watch src/index.ts"
  }
}

tsx (Node.js 18+)

tsx is a TypeScript execution engine powered by esbuild. It works as a drop-in replacement for node and runs on Node.js 18+, making it a good option when you cannot use Node.js 25+. Since @connectum/* packages ship compiled .js, no special configuration is needed.

npx tsx src/index.ts

In package.json:

{
  "scripts": {
    "start": "tsx src/index.ts",
    "dev": "tsx --watch src/index.ts"
  }
}

TIP

Install tsx as a devDependency (pnpm add -D tsx) for faster invocation without npx.

Comparison

Feature	Node.js 25+	Bun	tsx (Node.js 18+)
Your .ts files	Native type stripping	Native	esbuild
@connectum/* packages	Compiled .js (no loader needed)	Compiled .js (no loader needed)	Compiled .js (no loader needed)
--watch mode	node --watch	bun --watch	tsx --watch
Proto enum support	Requires two-step generation	Native	Native (esbuild)
Min Node.js version	25.2.0 (for native .ts execution)	N/A (Bun runtime)	18.0.0

Docker

In Dockerfiles, use the appropriate CMD for your runtime:

# Node.js 25+ (native TypeScript for your own .ts files)
CMD ["node", "src/index.ts"]

# Bun
CMD ["bun", "src/index.ts"]

# tsx (Node.js 18+)
CMD ["npx", "tsx", "src/index.ts"]

Related

• TypeScript Overview -- back to overview
• Erasable Syntax -- constraints for native TypeScript execution
• Proto Enums -- workaround for proto enum generation
• @connectum/core -- Package Guide