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deno init, start a new project

Command-line Usage

deno init [OPTIONS] [dir]

scaffolds a basic Deno project with a script, test, and configuration file


Options Jump to heading

--lib Jump to heading

Generate an example library project.

--serve Jump to heading

Generate an example project for deno serve.

Examples Jump to heading

$ deno init
✅ Project initialized
Run these commands to get started

  // Run the program
  deno run main.ts

  // Run the program and watch for file changes
  deno task dev

  // Run the tests
  deno test

$ deno run main.ts
Add 2 + 3 = 5

$ deno test
Check file:///dev/main_test.ts
running 1 test from main_test.ts
addTest ... ok (6ms)

ok | 1 passed | 0 failed (29ms)

This subcommand will create two files (main.ts and main_test.ts). These files provide a basic example of how to write a Deno program and how to write tests for it. The main.ts file exports a add function that adds two numbers together and the main_test.ts file contains a test for this function.

You can also specify an argument to deno init to initialize a project in a specific directory:

$ deno init my_deno_project
✅ Project initialized

Run these commands to get started

  cd my_deno_project

  // Run the program
  deno run main.ts

  // Run the program and watch for file changes
  deno task dev

  // Run the tests
  deno test

Init a JSR package Jump to heading

By running deno init --lib Deno will bootstrap a project that is ready to be published on JSR.

$ deno init --lib
✅ Project initialized

Run these commands to get started

  # Run the tests
  deno test

  # Run the tests and watch for file changes
  deno task dev

  # Publish to JSR (dry run)
  deno publish --dry-run

Inside deno.json you'll see that the entries for name, exports and version are prefilled.

{
  "name": "my-lib",
  "version": "0.1.0",
  "exports": "./mod.ts",
  "tasks": {
    "dev": "deno test --watch mod.ts"
  },
  "imports": {
    "@std/assert": "jsr:@std/assert@1"
  }
}

Initialize a web server Jump to heading

Running deno init --serve bootstraps a web server that works with deno serve.

$ deno init --serve
✅ Project initialized

Run these commands to get started

  # Run the server
  deno serve -R main.ts

  # Run the server and watch for file changes
  deno task dev

  # Run the tests
  deno -R test

Your deno.json file will look like this:

{
  "tasks": {
    "dev": "deno serve --watch -R main.ts"
  },
  "imports": {
    "@std/assert": "jsr:@std/assert@1",
    "@std/http": "jsr:@std/http@1"
  }
}

Now, you can start your web server, which watches for changes, by running deno task dev.

$ deno task dev
Task dev deno serve --watch -R main.ts
Watcher Process started.
deno serve: Listening on http://0.0.0.0:8000/