Hello World

Your First Program

Create a file called hello.ts:

console.log("Hello, Perry!");

Compile and run it:

perry hello.ts -o hello
./hello

Output:

Hello, Perry!

That’s it. Perry compiled your TypeScript to a native executable — no Node.js, no bundler, no runtime.

A Slightly Bigger Example

function fibonacci(n: number): number {
  if (n <= 1) return n;
  return fibonacci(n - 1) + fibonacci(n - 2);
}

const start = Date.now();
const result = fibonacci(40);
const elapsed = Date.now() - start;

console.log(`fibonacci(40) = ${result}`);
console.log(`Completed in ${elapsed}ms`);

perry fib.ts -o fib
./fib

This runs about 2x faster than Node.js because Perry compiles to native machine code with integer specialization.

Using Variables and Functions

const name: string = "World";
const items: number[] = [1, 2, 3, 4, 5];

const doubled = items.map((x) => x * 2);
const sum = doubled.reduce((acc, x) => acc + x, 0);

console.log(`Hello, ${name}!`);
console.log(`Sum of doubled: ${sum}`);

Async Code

async function fetchData(): Promise<string> {
  const response = await fetch("https://httpbin.org/get");
  const data = await response.json();
  return data.origin;
}

const ip = await fetchData();
console.log(`Your IP: ${ip}`);

perry fetch.ts -o fetch
./fetch

Perry compiles async/await to a native async runtime backed by Tokio.

What the Compiler Produces

When you run perry file.ts -o output, Perry:

Parses your TypeScript with SWC
Lowers the AST to an intermediate representation (HIR)
Applies optimizations (inlining, closure conversion, etc.)
Generates native machine code with Cranelift
Links with your system’s C compiler

The result is a standalone executable with no external dependencies.

Binary Size

Program	Binary Size
Hello world	~300KB
CLI with fs/path	~3MB
UI app	~3MB
Full app with stdlib	~48MB

Perry automatically detects which runtime features you use and only links what’s needed.

Perry Documentation