"- If the original English content has added parts, also add these parts to the translation.",
                "- If the original English content has removed parts, also remove them from the translation, unless you were instructed earlier to not do that in specific cases.",
                "- If parts of the original English content have changed, also change those parts in the translation.",

# Using Dataclasses { #using-dataclasses }

FastAPI is built on top of **Pydantic**, and I have been showing you how to use Pydantic models to declare requests and responses.

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

{* ../../docs_src/dataclasses_/tutorial001_py310.py hl[1,6:11,18:19] *}

# GraphQL { #graphql }

As **FastAPI** is based on the **ASGI** standard, it's very easy to integrate any **GraphQL** library also compatible with ASGI.

You can combine normal FastAPI *path operations* with GraphQL on the same application.

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

        a_uuid: MyUuid

        @field_serializer("a_uuid")
        def serialize_a_uuid(self, v):
            return str(v)

    @app.get("/get_custom_class")
    def return_some_user():
        # Test that the fix also works for custom pydantic classes
        return SomeCustomClass(a_uuid=MyUuid("b8799909-f914-42de-91bc-95c819218d01"))

    client = TestClient(app)

    with client:
        response_simple = client.get("/fast_uuid")

                includeModule('gradle', 'gradle')
            }
        }
    }
}

// We support multiple accepted public api changes JSON files, but "accepted-public-api-changes.json"
// is the "main" one that is also shown in HTML report
def apiChangesJsonDirectory = layout.projectDirectory.dir("src/changes/accepted-changes")

def compatibilityBaselineVersion = gradleModule.identity.releasedVersions.get().mostRecentRelease.version

    Convert any object to something that can be encoded in JSON.

    This is used internally by FastAPI to make sure anything you return can be
    encoded as JSON before it is sent to the client.

    You can also use it yourself, for example to convert objects before saving them
    in a database that supports only JSON.

    Read more about it in the

# Prevent regressions on those two incompatible changes
# TODO: remove those flags when they are flipped in the default Bazel version TF uses.
common --incompatible_enforce_config_setting_visibility
# TODO: also enable this flag after fixing the visibility violations
# common --incompatible_config_setting_private_default_visibility

# TODO: Enable Bzlmod
common --noenable_bzlmod
common --enable_workspace

### German instructions, when to use and when not to use hyphens in words (written in first person, which is you)

* The same PR [#4575](https://github.com/tiangolo/fastapi/pull/4575) from above also fixes the `contextvars` context for the code before and after `yield`. This was the main objective of that PR.

This means that now, if you set a value in a context variable before `yield`, the value would still be available after `yield` (as you would intuitively expect). And it also means that you can reset the context variable with a token afterwards.