<velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
              <version>2.0.0</version>
              <models>
                <model>src/main/mdo/plugin.mdo</model>
              </models>
              <templates>
                <template>model.vm</template>
              </templates>
              <params>
                <param>packageModelV4=org.apache.maven.api.plugin.descriptor</param>

    response = client.post("/tuple-of-models/", json=data)
    assert response.status_code == 422, response.text

    data = [{"x": 1, "y": 2}]
    response = client.post("/tuple-of-models/", json=data)
    assert response.status_code == 422, response.text


def test_tuple_form_valid():
    response = client.post("/tuple-form/", data={"values": ("1", "2")})

Quando você cria uma *operação de rota* no **FastAPI**, normalmente você pode retornar qualquer dado: um `dict`, uma `list`, um modelo do Pydantic, um modelo do banco de dados, etc.

Se você declarar um [Modelo de resposta](../tutorial/response-model.md), o FastAPI irá usá-lo para serializar os dados para JSON, usando o Pydantic.

### Model for Input { #model-for-input }

If you use this model as an input like here:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

...then the `description` field will **not be required**. Because it has a default value of `None`.

### Input Model in Docs { #input-model-in-docs }

          <execution>
            <id>modello-v3</id>
            <goals>
              <goal>velocity</goal>
            </goals>
            <configuration>
              <version>1.1.0</version>
              <models>
                <model>../../api/maven-api-metadata/src/main/mdo/metadata.mdo</model>
              </models>
              <templates>
                <template>model-v3.vm</template>
              </templates>

It improves editor support for Pydantic models, with:

* auto-completion
* type checks
* refactoring
* searching
* inspections

///

## Use the model { #use-the-model }

Inside of the function, you can access all the attributes of the model object directly:

{* ../../docs_src/body/tutorial002_py310.py *}

    <version>11-SNAPSHOT</version>
  </parent>

  <artifactId>child-artifact-id</artifactId>
  <name>Model inheritance test parent: module directory != artifactId</name>
  <description>
    artifactId == "child-artifact-id"
    but expect path on SCM and site == "child"
    feature: support "project.directory" property, ressembling future model addition of "directory" element along "artifactId"
  </description>

  <properties>

Si vous déclarez un [Modèle de réponse](../tutorial/response-model.md), FastAPI l'utilise pour sérialiser les données en JSON, en utilisant Pydantic.

      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>
          <version>4.2.0</version>
          <velocityBasedir>${project.basedir}/../../src/mdo</velocityBasedir>
          <models>
            <model>src/main/mdo/maven.mdo</model>
          </models>
          <templates>
            <template>model.vm</template>
          </templates>

## Otimizar Desempenho da Resposta - Modelo de Resposta - Tipo de Retorno { #optimize-response-performance-response-model-return-type }