How to deploy a Sinatra app | Ample

The short version

To deploy a Sinatra 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 rackup -o 0.0.0.0 -p $PORT and returns a public HTTPS URL.

Deploy Sinatra

  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.

curl -fsSL https://get.ample.computer/install.sh | sh
ample auth signup
# then, in your agent:
# "Deploy this Sinatra app to Ample"
  1. 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
  1. 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.

  1. 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 rackup -o 0.0.0.0 -p $PORT | | Tested size | s-1vcpu-1gb |

Verified on Sinatra: 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 rackup (config.ru) reading PORT on the ruby-3.4 template.

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

Before you deploy

You need

Know the limits

Frequently asked questions

Do I need a Dockerfile to deploy Sinatra?

No. Ample detects Sinatra 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 Sinatra 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 Sinatra.

What does it cost to host a Sinatra 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.

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 Sinatra.