What about my add-ons?

PostgreSQL databases, Redis-compatible caches, S3 storage and scheduled jobs all have their equivalent in while.

Do I need to write a Dockerfile?

No, while recognizes a Node.js, Python or Go app on its own.

Can I keep Heroku until I have checked everything?

Yes, your app runs on while at its own address before you switch your domain over.

Migrate from Heroku over MCP, without a rewrite

Is your Heroku bill climbing? Connected to while over MCP, your agent takes your app as it is, copies your database, and deploys it in France.

Prerequisites

An app on Heroku, in Node.js, Python or Go.
Access to your Heroku account, to export the database.
An AI agent that works in a terminal: Claude Code, Codex, Cursor or Gemini CLI.

Step 1: Give your agent these instructions

Open your agent in your app’s folder and paste these instructions into it:

Instructions

Connect to while with my account (while.sh/agents), then deploy my app.

Without an account, your agent deploys your app as a trial, in one request. To keep it, open the link it gives you and create your account.

With your account, your agent adds while’s MCP server itself. If it asks you to, restart it. On the first call to while, a page opens in your browser. In Claude Code, if it doesn’t open, type /mcp, choose while, then Authenticate. On that page, choose your app, or “A new app”, then click Authorize.

Step 2: Open your app

Your agent gives you your app’s address, for example https://mon-appli.while.cloud, over HTTPS.

What your agent does

It writes while.yaml at the root of your app:

while.yaml

apiVersion: while/v1
project: mon-appli
services:
  - name: web
    port: 5006
    health:
      path: /

Heroku’s Node.js example ran on while without a single line changed².

Copy your Heroku Postgres database

You, to your agent: Copy our Heroku database to while.

Your agent exports the database with pg_dump, then loads it into while.

Carry over your variables

You, to your agent: Carry over our Heroku config vars.

Your agent carries your settings over to while. You enter your secret keys yourself: your agent never sees them.

Replace Heroku Scheduler

You, to your agent: Bring over the Heroku Scheduler jobs.

Your agent declares them as scheduled jobs, at the same times.

Move to your own domain

You, to your agent: Put the app on www.acme.com.

Your agent declares the domain, you add the DNS records it gives you, and the HTTPS certificate follows.

Go back to the previous version

You, to your agent: Go back to the previous version.

In the 30 minutes after a deployment, the previous version comes back in a second. After that, it takes a few seconds. Once the previous version is back, your agent reads what broke in while’s logs, fixes it and deploys again.

In the docs: Scheduled jobs, Custom domain, Versions and rollback and Variables and secrets.

Leave Heroku without rewriting your app, from your AI agent