### OpenID (not "OpenID Connect")

There was also an "OpenID" specification. That tried to solve the same thing as **OpenID Connect**, but was not based on OAuth2.

So, it was a complete additional system.

It is not very popular or used nowadays.

## OpenAPI

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

`example` e `examples` são adicionados a <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#parameter-object" class="external-link" target="_blank">definição do OpenAPI, dentro do `Parameter Object` (na especificação)</a>.

E para `Body()`, `File()`, e `Form()`, o `example` e `examples` são de maneira equivalente adicionados para a <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#mediaTypeObject" class="external-link" target="_blank">definição...

* <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#parameter-object" class="external-link" target="_blank">`Parameter Object` (in the specification)</a> that was used by FastAPI's:
    * `Path()`
    * `Query()`
    * `Header()`
    * `Cookie()`

    deprecated: Optional[bool] = None
    readOnly: Optional[bool] = None
    writeOnly: Optional[bool] = None
    examples: Optional[List[Any]] = None
    # Ref: OpenAPI 3.1.0: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#schema-object
    # Schema Object
    discriminator: Optional[Discriminator] = None
    xml: Optional[XML] = None
    externalDocs: Optional[ExternalDocumentation] = None

    def __init__(
        self,
        code: Annotated[
            int,
            Doc(
                """
                A closing code from the
                [valid codes defined in the specification](https://datatracker.ietf.org/doc/html/rfc6455#section-7.4.1).
                """
            ),
        ],
        reason: Annotated[
            Union[str, None],
            Doc(
                """

!!! note "Détails techniques"
    La spécification OpenAPI appelle ces métadonnées des <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#operation-object" class="external-link" target="_blank">Objets d'opération</a>.

    ```Python hl_lines="7"
    {!> ../../../docs_src/request_forms/tutorial001.py!}
    ```

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

The <abbr title="specification">spec</abbr> requires the fields to be exactly named `username` and `password`, and to be sent as form fields, not JSON.

### The callback path expression

* *路径*可以包含 <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#key-expression" class="external-link" target="_blank">OpenAPI 3 表达式</a>（详见下文），可以使用带参数的变量，以及发送至您的 API 的原始请求的部分

### 回调路径表达式

回调*路径*支持包含发送给您的 API 的原始请求的部分的  <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#key-expression" class="external-link" target="_blank">OpenAPI 3 表达式</a>。

!!! note "Technical details"
    In the OpenAPI specification it is called the <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#operation-object" class="external-link" target="_blank">Operation Object</a>.