## The short version

To deploy a Rails app on Ample, run `ample deploy . --name <app-name> --public` in the project directory, or ask your coding agent to deploy it to Ample. Ample builds it on the `ruby-3.4` template, starts it with `bundle exec rails server -b 0.0.0.0 -p $PORT` and returns a public HTTPS URL.

## Deploy Rails

1. 1

### Ask your coding agent

Install the Ample CLI and create an account (no browser or card needed), then ask Claude Code, Codex, Cursor or any agent with a shell to deploy the project. See [Ample for coding agents](/content/agents/index.html).

```
curl -fsSL https://get.ample.computer/install.sh | sh
ample auth signup
# then, in your agent:
# "Deploy this Rails app to Ample"
```

2. 2

### Or deploy from the CLI

Run the deploy once from the project directory. It waits until the app is live or failed and prints the URL; exit 0 is live, 1 failed, 2 needs input.

```
ample deploy . --name <app-name> --public
```

3. 3

### Or use MCP

Agents connected to the Ample MCP server (`https://api.ample.computer/mcp`, or `ample mcp` over stdio) call `ample_deploy` with the same arguments.

4. 4

### Verify

Open the URL. If the deploy failed, read the build log, then the runtime log, fix the cause and deploy again.

```
ample logs <deployment_id> --kind build
```

## What Ample runs

| Template | `ruby-3.4` |
| Install | `bundle config set --local path vendor/bundle && bundle config set --local without 'development test' && bundle install` |
| Start | `bundle exec rails server -b 0.0.0.0 -p $PORT` |
| Tested size | `s-1vcpu-1gb` |

Verified on Rails: the app built and started with the documented commands and answered on its public HTTPS URL. Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production.

Last verification (September 20, 2026): Rails pattern fixture deployed on Ample (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production); for this guide: the app built and started with the documented commands and answered on its public HTTPS URL.

## Before you deploy

### You need

- A Rails project (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production)
- An Ample account token with servers:write

### Know the limits

- Verified on the ruby-3.4 template at s-1vcpu-1gb; other sizes and Rails major versions are not verified.

## Move a Rails app to Ample

- [How to move a Rails app from AWS EC2 to Ample](/content/migrate/aws-ec2-app/rails/index.html)
- [How to move a Rails app from DigitalOcean Droplet to Ample](/content/migrate/digitalocean-droplet-app/rails/index.html)
- [How to move a Rails app from Fly.io to Ample](/content/migrate/fly-io-app/rails/index.html)
- [How to move a Rails app from Heroku to Ample](/content/migrate/heroku-app/rails/index.html)
- [How to move a Rails app from Netlify to Ample](/content/migrate/netlify-web-app/rails/index.html)
- [How to move a Rails app from Railway to Ample](/content/migrate/railway-app/rails/index.html)
- [How to move a Rails app from Render web service to Ample](/content/migrate/render-web-service/rails/index.html)
- [How to move a Rails app from Vercel to Ample](/content/migrate/vercel-app/rails/index.html)

## Frequently asked questions

### Do I need a Dockerfile to deploy Rails?

No. Ample detects Rails from the repository and builds it from source on the `ruby-3.4` template. Dockerfile build steps are not run.

### How do I add a database to a Rails app?

Leave DATABASE_URL unset and deploy: when the code needs Postgres, MySQL, Redis or MongoDB, Ample creates a managed database and passes its connection string to the app. See [Connect Postgres for Rails](/content/guides/rails/database-connection/index.html).

### What does it cost to host a Rails app on Ample?

The Free plan runs 2 apps at once with no card and a hard monthly budget, so it never bills you. Larger needs are priced on volume; see [pricing](/content/pricing/index.html).

### What if the deploy fails?

`ample deploy` waits until the app is live or failed. A failure returns who must act, a diagnosis and a suggested fix; read the logs with `ample logs <deployment_id> --kind build`. See [Diagnose deployment failures for Rails](/content/guides/rails/deployment-diagnostics/index.html).

## More for Rails

[Rails **How to serve Rails public assets through a CDN on Ample**](/content/guides/rails/cdn-assets/index.html) [Rails **How to set environment variables and secrets for a Rails app on Ample**](/content/guides/rails/configuration-secrets/index.html) [Rails **How to connect a Rails app to Postgres on Ample**](/content/guides/rails/database-connection/index.html) [Rails **How to fix a failed Rails deploy on Ample**](/content/guides/rails/deployment-diagnostics/index.html) [Rails **How to use S3-compatible storage from a Rails app on Ample**](/content/guides/rails/object-client/index.html) [Rails **How to serve private files from a Rails app on Ample**](/content/guides/rails/private-file-access/index.html) [Rails **How to run database migrations for a Rails app on Ample**](/content/guides/rails/schema-changes/index.html)