Procfile Reference

A Procfile declares the process types your app uses. Place it in the root of your repository.

Format

<process type>: <command>

Examples

Node.js

web: node server.js
worker: node worker.js

Python

web: gunicorn app:app --bind 0.0.0.0:$PORT
worker: celery -A tasks worker

PHP

web: vendor/bin/heroku-php-apache2 public/

Process Types

• web — Receives HTTP traffic. Must bind to $PORT environment variable.
• worker — Background job processor. Does not receive HTTP traffic.

Notes

• If no Procfile exists, the buildpack will try to auto-detect how to start your app
• The web process is required for HTTP apps
• Scale processes from the Scale tab in your app dashboard
• Each process type runs in its own container