fields `username` and `password`.

    All the initialization parameters are extracted from the request.

    The only difference between `OAuth2PasswordRequestFormStrict` and
    `OAuth2PasswordRequestForm` is that `OAuth2PasswordRequestFormStrict` requires the
    client to send the form field `grant_type` with the value `"password"`, which
    is required in the OAuth2 specification (it seems that for no particular reason),

/// tip | Dica

A especificação OAuth2 na verdade *requer* um campo `grant_type` com um valor fixo de `password`, mas `OAuth2PasswordRequestForm` não o impõe.

Se você precisar aplicá-lo, use `OAuth2PasswordRequestFormStrict` em vez de `OAuth2PasswordRequestForm`.

///

* Um `client_id` opcional (não precisamos dele em nosso exemplo).
* Um `client_secret` opcional (não precisamos dele em nosso exemplo).

* Enable `showCommonExtensions` in Swagger UI to show additional validations like `maxLength`, etc. PR [#1466](https://github.com/tiangolo/fastapi/pull/1466) by [@TiewKH](https://github.com/TiewKH).
* Make `OAuth2PasswordRequestFormStrict` importable directly from `fastapi.security`. PR [#1462](https://github.com/tiangolo/fastapi/pull/1462) by [@RichardHoekstra](https://github.com/RichardHoekstra).