* In code blocks within the Markdown document, translate comments (`# a comment`), but leave the rest unchanged.

* Do not change anything enclosed in "``" (inline code).

* In lines starting with `===` or `!!!`, translate only the ` "... Text ..."` part. Leave the rest unchanged.

* <a href="https://strawberry.rocks/" class="external-link" target="_blank">Strawberry</a> 🍓
    * With <a href="https://strawberry.rocks/docs/integrations/fastapi" class="external-link" target="_blank">docs for FastAPI</a>
* <a href="https://ariadnegraphql.org/" class="external-link" target="_blank">Ariadne</a>

## Additional servers

!!! warning
    This is a more advanced use case. Feel free to skip it.

By default, **FastAPI** will create a `server` in the OpenAPI schema with the URL for the `root_path`.

But you can also provide other alternative `servers`, for example if you want *the same* docs UI to interact with a staging and production environments.

## Dataclasses in Nested Data Structures

You can also combine `dataclasses` with other type annotations to make nested data structures.

In some cases, you might still have to use Pydantic's version of `dataclasses`. For example, if you have errors with the automatically generated API documentation.

In that case, you can simply swap the standard `dataclasses` with `pydantic.dataclasses`, which is a drop-in replacement:

So, you can use it with:

```Python hl_lines="6"
{!../../../docs_src/path_params/tutorial004.py!}
```

!!! tip
    You could need the parameter to contain `/home/johndoe/myfile.txt`, with a leading slash (`/`).

    In that case, the URL would be: `/files//home/johndoe/myfile.txt`, with a double slash (`//`) between `files` and `home`.

## Recap

      - uses: actions/checkout@v4
        with:
          # To allow latest-changes to commit to the main branch
          token: ${{ secrets.FASTAPI_LATEST_CHANGES }}
      # Allow debugging with tmate
      - name: Setup tmate session
        uses: mxschmitt/action-tmate@v3
        if: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.debug_enabled == 'true' }}
        with:
          limit-access-to-actor: true

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.11"
          # Issue ref: https://github.com/actions/setup-python/issues/436
          # cache: "pip"
          # cache-dependency-path: pyproject.toml
      - uses: actions/cache@v4
        id: cache
        with:
          path: ${{ env.pythonLocation }}

Nevertheless, Uvicorn is currently only compatible with asyncio, and it normally uses <a href="https://github.com/MagicStack/uvloop" class="external-link" target="_blank">`uvloop`</a>, the high-performance drop-in replacement for `asyncio`.

But if you want to directly use **Trio**, then you can use **Hypercorn** as it supports it. ✨

### Install Hypercorn with Trio

First you need to install Hypercorn with Trio support:

<div class="termy">

Import `TestClient`.

Create a `TestClient` by passing your **FastAPI** application to it.

Create functions with a name that starts with `test_` (this is standard `pytest` conventions).

Use the `TestClient` object the same way as you do with `httpx`.

Write simple `assert` statements with the standard Python expressions that you need to check (again, standard `pytest`).

```Python hl_lines="2  12  15-18"

You can see those schemas because they were declared with the models in the app.

That information is available in the app's **OpenAPI schema**, and then shown in the API docs (by Swagger UI).

And that same information from the models that is included in OpenAPI is what can be used to **generate the client code**.

### Generate a TypeScript Client

Now that we have the app with the models, we can generate the client code for the frontend.