5-minute quickstart

1. Install and verify

curl -fsSL https://deno.land/install.sh | sh
deno --version

irm https://deno.land/install.ps1 | iex
deno --version

docker run --rm denoland/deno:latest deno --version

2. Initialize and run

deno init --serve hello-deno
cd hello-deno
deno task dev

deno init --serve creates deno.json, a server entry point, and tests. For a hand-written entry point, make the network permission explicit:

Deno.serve((_request) => Response.json({ ok: true }));

deno run --allow-net main.ts
curl http://localhost:8000
# {"ok":true}

3. Add a test

import { assertEquals } from "jsr:@std/assert";

Deno.test("adds two numbers", () => {
  assertEquals(2 + 3, 5);
});

deno test

4. Pre-commit gate

deno fmt --check
deno lint
deno check **/*.ts
deno test

Official sources: Get started, Installation, and Testing.