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1.0.0 • Public • Published


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Command line tools for Fastify. Generate, write and run an application with one single command!


npm install fastify-cli --global


fastify-cli offers a single command line interface for your fastify project:

$ fastify

Will print an help:

Fastify command line interface, available commands are:

  * start         start a server
  * generate      generate a new project
  * readme        generate a for the plugin
  * version       the current fastify-cli version
  * help          help about commands

Launch 'fastify help [command]' to know more about the commands.

The default command is start, you can hit

  fastify start plugin.js

to start plugin.js.


You can start any Fastify plugin with:

$ fastify start plugin.js

A plugin can be as simple as:

// plugin.js
module.exports = function (fastify, options, next) {
  fastify.get('/', function (req, reply) {
    reply.send({ hello: 'world' })

If you are using Node 8+, you can use async functions too:

// async-await-plugin.js
module.exports = async function (fastify, options) {
  fastify.get('/', async function (req, reply) {
    return { hello: 'world' }

For a list of available flags for fastify start see the help: fastify help start.

If you want to use custom options, just export an options object with your route and run the cli command with the --options flag.

// plugin.js
module.exports = function (fastify, options, next) {
  fastify.get('/', function (req, reply) {
    reply.send({ hello: 'world' })
module.exports.options = {
  https: {
    key: 'key',
    cert: 'cert'


You can pass the following options via cli arguments, every options has the corresponding environment variable:

Description Short command Full command Environment variable
Port to listen on (default to 3000) -p --port FASTIFY_PORT or PORT
Address to listen on -a --address FASTIFY_ADDRESS
Socket to listen on -s --socket FASTIFY_SOCKET
Log level (default to fatal) -l --log-level FASTIFY_LOG_LEVEL
Prints pretty logs -P --pretty-logs FASTIFY_PRETTY_LOGS
Watch process.cwd() directory for changes, recursively; when that happens, the process will auto reload. -w --watch FASTIFY_WATCH
Ignore changes to the specified files or directories when watch is enabled. (e.g. --ignore-watch='node_modules .git logs/error.log' ) --ignore-watch FASTIFY_IGNORE_WATCH
Use custom options -o --options FASTIFY_OPTIONS
Set the prefix -r --prefix FASTIFY_PREFIX
Set the plugin timeout -T --plugin-timeout FASTIFY_PLUGIN_TIMEOUT
Defines the maximum payload, in bytes,
the server is allowed to accept

By default fastify-cli runs dotenv, so it will load all the env variables stored in .env in your current working directory.

The default value for --plugin-timeout is 10 seconds.

Fastify version discovery

If Fastify is installed as a project dependency (with npm install --save fastify), then fastify-cli will use that version of Fastify when running the server. Otherwise, fastify-cli will use the version of Fastify included within fastify-cli.

Migrating out of fastify-cli start

If you would like to turn your application into a standalone executable, just add the following server.js:

'use strict'
// Read the .env file.
// Require the framework
const Fastify = require('fastify')
// Instantiate Fastify with some config
const app = Fastify({
  logger: true,
  pluginTimeout: 10000
// Register your application as a normal plugin.
// Start listening.
app.listen(process.env.PORT || 3000, (err) => {
  if (err) {

Unhandled rejections

fastify-cli uses make-promises-safe to avoid memory leaks in case of a 'unhandledRejection'.


fastify-cli can also help with generating some project scaffolding to kickstart the development of your next Fastify application. To use it:

  1. fastify generate <yourapp>
  2. cd yourapp
  3. npm install

The sample code offers you four npm tasks:

  • npm start - starts the application
  • npm run dev - starts the application with pino-colada pretty logging (not suitable for production)
  • npm test - runs the tests

You will find three different folders:

  • plugins: the folder where you will place all your custom plugins
  • services: the folder where you will declare all your endpoints
  • test: the folder where you will declare all your test

Finally there will be an app.js file, which is your entry point. It is a standard Fastify plugin and you will not need to add the listen method to run the server, just run it with one of the scripts above.


fastify-cli can also help with generating a concise and informative readme for your plugin. If no package.json was provided a new one is generated automatically. To use it:

  1. cd yourplugin
  2. fastify readme <path-to-your-plugin-file>

Finally there will be a new file, which provides internal informations about your plugin e.g:

  • Install instructions
  • Example usage
  • Plugin dependencies
  • Exposed decorators
  • Encapsulation semantic
  • Compatible Fastify version


fastify-cli is unopinionated on the choice of linter. We recommend you to add a linter, like so:

"devDependencies": {
+ "standard": "^11.0.1",
"scripts": {
+ "pretest": "standard",
  "test": "tap test/**/*.test.js",
  "start": "fastify start -l info app.js",
  "dev": "fastify start -l info -P app.js",
+ "lint": "standard --fix"


If you feel you can help in any way, be it with examples, extra testing, or new features please open a pull request or open an issue.

The code follows the Standard code style. js-standard-style



The software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non infringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.

Copyright © 2016-2018 Fastify Team


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