Create, validate, and render Heroku app.json manifests


133150.8.38 years ago8 years agoMinified + gzip package size for apps in KB



apps is a node module for creating and validating Heroku app.json files. It works in node.js and the browser, and also has a CLI.


The app.json schema is defined using the JSON Schema specification and is validated with the awesome revalidator node module.

See the schema at schema.js.

Installation and Usage

Programmatic usage with Node.js or Browserify

Download the module from npm and save it to your package.json:

npm install apps --save

Require it in your script:

var App = require("apps")

Usage in the Browser (without Browserify)

If browserify isn't your thing, use the pre-compiled browser-ready bundle in dist/app.js. Include this file in your html page and it will create window.App for you.

Usage on the Command Line

To use this module on the command line, you'll need to install it globally using npm:

npm install apps --global

Now you can run app or apps from any directory:

$ app

  Usage: app [options] [command]


    schema [options]       Write the app.json schema to STDOUT


    -h, --help     output usage information
    -V, --version  output the version number

  Use 'app <command> --help' to get more information about a specific command.

Class Methods

Instantiate with a JSON filename:

var app = + "/path/to/app.json")

Instantiate with a JSON string:

var json = "{name: \"small-sharp-tool\", description: \"This app does one little thing, and does it well.\"}"
var app =

Instantiate with a JavaScript object:

var app ={
  name: "small-sharp-tool",
  description: "This app does one little thing, and does it well."

App.fetch(url, callback)

You can fetch app manifests straight from GitHub. The github-raw-cors-proxy service is used to make the app.json file downloadable from browsers.

url can be a fully qualified GitHub URL, or a shorthand user/repo string:

App.fetch('zeke/harp-slideshow-template', function(err, manifest) {
  console.log(err, manifest)


Generates an example manifest from example content in the schema.


Instance Methods


A getter method that validates the app manifest and returns true or false


Returns null if app manifest is valid.

Returns an array of error objects if invalid:

  {property: "name", message: "is required"},
  {property: "website", message: "is not a valid url"}


Return a pretty JSON string representation of the manifest, without any superfluous properties.


Fetch pricing data about the app's required addons by hitting the Heroku Platform API.


npm install
npm test


To prepare a browser-ready bundle, run the following:

npm run build

# Wrote dist/app.js
# Wrote dist/app.min.js


Genarate human-friendly docs from the schema

npm run docs

# Wrote dist/
# Wrote dist/schema.html



If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from