Documentation = "https://fastapi.tiangolo.com/"
Repository = "https://github.com/tiangolo/fastapi"

[project.optional-dependencies]

standard = [
    "fastapi-cli >=0.0.2",
    # For the test client
    "httpx >=0.23.0",
    # For templates
    "jinja2 >=2.11.2",
    # For forms and file uploads
    "python-multipart >=0.0.7",
    # For UJSONResponse

* 🔧 Fix Ruff configuration unintentionally enabling and re-disabling mccabe complexity check. PR [#10893](https://github.com/tiangolo/fastapi/pull/10893) by [@jiridanek](https://github.com/jiridanek).
* ✅ Re-enable test in `tests/test_tutorial/test_header_params/test_tutorial003.py` after fix in Starlette. PR [#10904](https://github.com/tiangolo/fastapi/pull/10904) by [@ooknimm](https://github.com/ooknimm).

### Docs

By considering these concepts, you will be able to **evaluate and design** the best way to deploy **your own APIs**.

In the next chapters, I'll give you more **concrete recipes** to deploy FastAPI applications.

* **WebSocket** support.
* In-process background tasks.
* Startup and shutdown events.
* Test client built on HTTPX.
* **CORS**, GZip, Static Files, Streaming responses.
* **Session and Cookie** support.
* 100% test coverage.
* 100% type annotated codebase.

## Pydantic features

</p>
<p align="center">
<a href="https://github.com/tiangolo/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster" target="_blank">
    <img src="https://github.com/tiangolo/fastapi/workflows/Test/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://coverage-badge.samuelcolvin.workers.dev/redirect/tiangolo/fastapi" target="_blank">
    <img src="https://coverage-badge.samuelcolvin.workers.dev/tiangolo/fastapi.svg" alt="Coverage">

</p>
<p align="center">
<a href="https://github.com/tiangolo/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster" target="_blank">
    <img src="https://github.com/tiangolo/fastapi/workflows/Test/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://coverage-badge.samuelcolvin.workers.dev/redirect/tiangolo/fastapi" target="_blank">
    <img src="https://coverage-badge.samuelcolvin.workers.dev/tiangolo/fastapi.svg" alt="Coverage">

```Python hl_lines="9-10  13  21"
{!../../../docs_src/settings/app02/test_main.py!}
```

In the dependency override we set a new value for the `admin_email` when creating the new `Settings` object, and then we return that new object.

Then we can test that it is used.

## Reading a `.env` file

```Python hl_lines="2-3  23"
{!../../../docs_src/wsgi/tutorial001.py!}
```

## Check it

Now, every request under the path `/v1/` will be handled by the Flask application.

And the rest will be handled by **FastAPI**.

If you run it and go to <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a> you will see the response from Flask:

```txt

    This is where we'll put the `requirements.txt` file and the `app` directory.

3. Copy the file with the requirements to the `/code` directory.

    Copy **only** the file with the requirements first, not the rest of the code.

    As this file **doesn't change often**, Docker will detect it and use the **cache** for this step, enabling the cache for the next step too.

4. Install the package dependencies in the requirements file.