§ Node.js

Node.js is supported by the Node.js buildpack.

§ Detection

The Node.js buildpack is used if the repository contains a package.json file.

§ Dependencies

Dependencies are managed using npm. npm expects dependencies specified under the dependencies attribute inside the package.json file, which is just a simple object, with package names as the keys, mapping to version ranges.

§ Specifying a Node.js Version

Node.js version can be specified using the engines section of the package.json file. It uses semver.io to resolve the node version, so queries in the format of 0.8.x, >0.4, >=0.8.5 <=0.8.14 are supported. This buildpack can run any Node.js version past 0.8.5, including development versions.

§ Example package.json

  "name": "node-example",
  "version": "0.0.1",
  "dependencies": {
    "express": "4.10.0",
    "stylus": "0.49.2"
  "devDependencies": {
    "grunt": "0.4.5"
  "engines": {
    "node": "0.10.x",
    "npm": "1.2.x"

§ Custom Build Step

For apps that require extra processing before the deploy, an npm postinstall script can be added. It will run immediately after npm install --production, and the release environment will be available. Note that the buildpack doesn’t install devDependencies. Should you require any of those, they should be moved to dependencies.

§ Default Process Type

Node.js apps can be deployed without a Procfile. If no Procfile is present, the buildpack will expect a scripts.start key in the package.json file, and the default process type web will run the script using npm start.

§ Run Jobs

Besides the usual utilities, npm and node are in PATH and are available directly via flynn run.

$ flynn run node -v