///

### Funciones de *path operation* { #path-operation-functions }

Cuando declaras una *path operation function* con `def` normal en lugar de `async def`, se ejecuta en un threadpool externo que luego es esperado, en lugar de ser llamado directamente (ya que bloquearía el servidor).

        val distributionRuntimeOnly = bucket("${prefix}TestDistributionRuntimeOnly", "Declare the distribution that is required to run tests")
        val localRepository = bucket("${prefix}TestLocalRepository", "Declare a local repository required as input data for the tests (e.g. :tooling-api)")

          // Since this is an artificially generated type variable, we don't bother checking
          // subtyping between declared type bound and actual type bound. So it's possible that we
          // may generate something like <capture#1-of ? extends Foo&SubFoo>.
          // Checking subtype between declared and actual type bounds
          // adds recursive isSubtypeOf() call and feels complicated.

You can declare a `response_model`, using the default status code `200` (or a custom one if you need), and then declare additional information for that same response in `responses`, directly in the OpenAPI schema.

**FastAPI** will keep the additional information from `responses`, and combine it with the JSON Schema from your model.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Query Parameters with a Pydantic Model { #query-parameters-with-a-pydantic-model }

We can do better...

## What makes a dependency { #what-makes-a-dependency }

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

The key factor is that a dependency should be a "callable".

And if you declared a `response_model`, it will still be used to filter and convert the object you returned.

**FastAPI** will use that *temporal* response to extract the status code (also cookies and headers), and will put them in the final response that contains the value you returned, filtered by any `response_model`.

     * supports version ranges and updates the given {@code parent} instance to match the returned {@code ModelSource}.
     * If {@code parent} declares a version range, the version corresponding to the returned {@code ModelSource} will
     * be set on the given {@code parent}.
     * </p>
     *
     * @param parent The parent coordinates to resolve, must not be {@code null}.

                    PluginValidationManager.IssueLocality.EXTERNAL,
                    session,
                    pluginArtifact,
                    "Plugin should declare Maven artifacts in `provided` scope. If the plugin already declares them in `provided` scope, update the maven-plugin-plugin to latest version. Artifacts found with wrong scope: "
                            + mavenArtifacts);
        }
    }

# Headers de Response { #response-headers }

## Usa un parámetro `Response` { #use-a-response-parameter }

Puedes declarar un parámetro de tipo `Response` en tu *path operation function* (como puedes hacer para cookies).

Y luego puedes establecer headers en ese objeto de response *temporal*.

{* ../../docs_src/response_headers/tutorial002_py39.py hl[1, 7:8] *}