## The short version

Configure build and start for a Flask app on Ample. 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.

## What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)

## Before you start

- 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

## How to do it

1. 1

### Make the start command bind correctly

Serve the WSGI app with a production server such as waitress from app.py reading PORT; pass --start "python3 app.py".

2. 2

### Deploy

Run the existing synchronous deploy once from the project directory and read the result. Exit 0 is live, 1 is failed, 2 is blocked on a required preflight action. Re-running with no change is a content-addressed no-op.

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

3. 3

### Verify

Fetch the live URL and run the success checks below. On failure read the build log, then the runtime log, fix the cause and deploy again; do not blind-retry.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **flask-basic canary** (`tests/deploy-canaries/flask-basic`): Flask app served by waitress.

## How to know it worked

- page or root route responds (`/` on the live URL, expect ample canary flask basic)

## Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. Plan quotas and budgets apply.

## Verification evidence

- canary_run on 2026-09-20T00:22:15Z at revision `1764076-tls-account-903d345`: Flask app served by waitress on python-3.12 and rendered the expected response. (expires 2027-03-19T00:22:15Z)

## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-20T01:55:48.667900+00:00 at revision `199ff1dfd526`. Binding state at export: schema_changed. Required scopes: servers:write.

## Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Flask (`GET /v1/catalog/nodes/stack%3Aframework-flask` on the api origin; authentication not required, approval not required)
- Browse Configure deployment (`GET /v1/catalog/nodes/intent%3Aconfigure-deployment` on the api origin; authentication not required, approval not required)
- Browse Public web service (`GET /v1/catalog/nodes/pattern%3Apublic-web-service` on the api origin; authentication not required, approval not required)

Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.

## Identifiers and status

Recipe `page:guides:flask:build-and-start`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**

Formats: [HTML](/content/guides/flask/build-and-start/index.html) | [Markdown](/content/guides/flask/build-and-start.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Aflask%3Abuild-and-start)