FastAPI Component for Diploi

Operation

Getting started

1. In the Dashboard, click Create Project +
2. Under Pick Components, choose FastAPI. Here you can also add a frontend framework to create a monorepo app, eg, FastAPI for backend and React+Vite for frontend
3. In Pick Add-ons, you can add one or multiple databases to your app
4. Choose Create Repository to generate a new GitHub repo
5. Finally, click Launch Stack

Link to the full guide https://diploi.com/blog/hosting_fastapi_apps

Python version

The default Python version is 3.12. You can change it in two ways:

• PYTHON_VERSION environment variable - set this in diploi.yaml as a static ENV under your component's environment variables. This controls the version used by both the development and production environments.
• .python-version file - add a .python-version file to your component's folder containing just the version number (e.g. 3.11). This is the standard convention used by uv and other Python tools, and is a good choice if you want the version pinned in your repository.

If both are set, the .python-version file takes precedence.

Development

The development server is started with:

uv run --with uvicorn uvicorn src.main:app --host 0.0.0.0 --port 8000 --reload --reload-dir src --reload-dir .venv/lib

This can be changed with the containerCommands.developmentStart field in diploi.yaml.

Production

Builds a production-ready image. During the build, dependencies are installed with uv sync or uv pip install. When the container starts, it runs:

uv run --with uvicorn uvicorn src.main:app --host 0.0.0.0 --port 8000 --proxy-headers

This can be changed with the containerCommands.productionStart field in diploi.yaml.

Links

• Adding FastAPI to a project
• FastAPI documentation
• Python documentation
• uv documentation