---
title: "How to deploy a Flask app"
description: "Deploy a Flask app to Ample with your coding agent, the CLI or MCP, using build and start commands verified on September 20, 2026."
canonical_url: "https://ample.computer/guides/flask"
last_updated: "2026-09-20"
author: "Ample Computer"
---

# How to deploy a Flask app

Deploy a Flask app to Ample with your coding agent, the CLI or MCP, using build and start commands verified on September 20, 2026.

## The short version

To deploy a Flask app on Ample, run `ample deploy . --name <app-name> --public --start "python3 run.py"` in the project directory, or ask your coding agent to deploy it to Ample. Ample builds it on the `python-3.12` template, starts it with `python3 run.py` and returns a public HTTPS URL. Python start commands are not inferred, so the command passes `--start`.

## Deploy Flask

1. **Ask your coding agent.** Install the Ample CLI and create an account, then ask your agent: "Deploy this Flask app to Ample".

   ```sh
   curl -fsSL https://get.ample.computer/install.sh | sh
   ample auth signup
   ```

2. **Or deploy from the CLI.** It waits until the app is live or failed and prints the URL.

   ```sh
   ample deploy . --name <app-name> --public --start "python3 run.py"
   ```

3. **Or use MCP.** Call `ample_deploy` on `https://api.ample.computer/mcp` (or `ample mcp` over stdio).
4. **Verify.** On failure read `ample logs <deployment_id> --kind build`, fix the cause and deploy again.

## Tested configuration

| | |
|---|---|
| Template | `python-3.12` |
| Install | `python3 -m pip install --target .ample/python -r requirements.txt` |
| Start | `PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 app.py` |
| Tested size | `s-1vcpu-1gb` |

Serve the WSGI app with a production server such as waitress from app.py reading PORT; pass --start "python3 app.py". Ample detects the runtime, installs dependencies, runs the build when present and starts the app on the python-3.12 template behind a public HTTPS URL.

Last verification (2026-09-20): Flask app served by waitress on python-3.12 and rendered the expected response.

## You need

- A requirements.txt (or pyproject) and a start command that reads PORT and binds 0.0.0.0
- An Ample account token with servers:write

## Know the limits

- Verified on the python-3.12 template at s-1vcpu-1gb; other templates and sizes are not verified by this recipe.
- The Flask development server was not used; waitress was tested.

## Frequently asked questions

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

No. Ample detects Flask from the repository and builds it from source on the `python-3.12` template. Dockerfile build steps are not run.

### How do I add a database to a Flask 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 Flask](https://ample.computer/guides/flask/database-connection).

### What does it cost to host a Flask 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](https://ample.computer/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 Flask](https://ample.computer/guides/flask/deployment-diagnostics).

## More for Flask

- [How to serve Flask public assets through a CDN on Ample](https://ample.computer/guides/flask/cdn-assets): Cdn assets for a Flask app on Ample
- [How to set environment variables and secrets for a Flask app on Ample](https://ample.computer/guides/flask/configuration-secrets): Configure environment variables and secrets for a Flask app on Ample
- [How to connect a Flask app to Postgres on Ample](https://ample.computer/guides/flask/database-connection): Connect a Flask app to PostgreSQL on Ample
- [How to fix a failed Flask deploy on Ample](https://ample.computer/guides/flask/deployment-diagnostics): Deployment diagnostics for a Flask app on Ample
- [How to use S3-compatible storage from a Flask app on Ample](https://ample.computer/guides/flask/object-client): Object storage client for a Flask app on Ample
- [How to serve private files from a Flask app on Ample](https://ample.computer/guides/flask/private-file-access): Private file access for a Flask app on Ample
- [How to run database migrations for a Flask app on Ample](https://ample.computer/guides/flask/schema-changes): Apply database schema changes for a Flask app on Ample with a release command