> ## Documentation Index
> Fetch the complete documentation index at: https://ravion-b90c0359-mintlify-710044b6.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# How to deploy Flask to AWS

> Deploy a Flask application on ECS Fargate behind an Application Load Balancer in your AWS account with Ravion, including autoscaling, HTTPS, and CI/CD.

Deploy Flask with Gunicorn on ECS Fargate behind an Application Load Balancer.

## Prerequisites

* A Git repository containing your application and its production build command.
* A Ravion account with your AWS account connected. Start free at [Ravion signup](https://app.ravion.com/signup).
* The Ravion CLI installed and authenticated. See [CLI installation](/cli/installation).

The examples use `my-org/my-app` as a placeholder. Replace it with your repository before applying the config.

<Prompt description="Set up this Flask app for Ravion ECS hosting." icon="sparkles" actions={["copy", "cursor"]}>
  1. Before any other action, read and follow [https://www.ravion.com/docs/start-here#agent-workflow](https://www.ravion.com/docs/start-here#agent-workflow) as the mandatory agent workflow.
  2. Use [https://www.ravion.com/docs/deploy/aws/flask](https://www.ravion.com/docs/deploy/aws/flask) as the framework-specific source of truth.
  3. Confirm this repository contains Flask and locate the app root in a monorepo.
  4. Inspect Python dependency files, app modules, Docker files, and scripts to detect the real Gunicorn target, factory syntax, port, and health path; never use Flask's development server.
  5. Generate `ravion.yaml` with `rvn-aws-network` + `rvn-ecs-cluster` + `rvn-ecs-web`, using real AWS account, region, repository, branch, and runtime values. Bind Gunicorn to `0.0.0.0`.
  6. Ask the user for AWS account IDs, repository slugs, project IDs, Python module paths, or ports before proceeding; do not guess.
</Prompt>

## Configure the deployment

Flask's production documentation recommends a dedicated WSGI server instead of the built-in development server.

This example uses [Railpack](https://railpack.com) for the build. Use `build_source: dockerfile` instead when you need a custom Dockerfile. Railpack detects Flask from the application dependencies.

Railpack detects Flask when `flask` is a dependency. It starts `gunicorn --bind 0.0.0.0:${PORT:-8000} main:app` only when `gunicorn` is also a dependency, so add Gunicorn to your requirements and use a custom start command when your module or application factory differs from `main:app`. Ravion injects `PORT` automatically from `container_port`.

```yaml ravion.yaml theme={null}
project:
  givenId: flask-app
  name: Flask app
environments:
  - givenId: production
    name: Production
    moduleInstances:
      - givenId: network
        name: Network
        type: rvn-aws-network
        version: 1.0.0
        input:
          aws_account_id: ravion-prod
          aws_region: us-east-1
          name: flask-production
      - givenId: cluster
        name: ECS cluster
        type: rvn-ecs-cluster
        version: 1.0.0
        input:
          network:
            moduleGivenIdRef: network
          name: flask-production
      - givenId: web
        name: Flask web service
        type: rvn-ecs-web
        version: 1.0.0
        input:
          cluster:
            moduleGivenIdRef: cluster
          name: flask-production-web
          build_source: railpack
          source_repo: my-org/my-flask-app
          container_port: 8000
          fargate_size:
            vcpu: 0.5
            memory_gb: 1
```

Gunicorn binds to port `8000` in this example. Use your application factory import path if the app is created by a function.

## Apply and connect your domain

```bash theme={null}
ravion project create --given-id flask-app --name "Flask app"
ravion project config apply flask-app --file ravion.yaml --dry-run
ravion project config apply flask-app --file ravion.yaml
```

Follow [custom domains](/guides/custom-domains) to connect your domain to the Application Load Balancer.

## Next steps

<CardGroup cols={2}>
  <Card title="Custom domains" icon="globe" href="/guides/custom-domains">
    Point a domain at your deployed service and manage its certificate.
  </Card>

  <Card title="Project config" icon="file-code" href="/config-as-code/project-config-file">
    Preview and apply Ravion configuration from source control.
  </Card>

  <Card title="Pipelines" icon="arrow-progress" href="/config-as-code/pipeline-config-file">
    Add approvals, migrations, and deployment automation.
  </Card>

  <Card title="Logs and metrics" icon="chart-line" href="/modules/logs">
    Inspect deploy output and production health in Ravion.
  </Card>
</CardGroup>