fastapi/docs/advanced/response-change-status-code.md
Sebastián Ramírez 0ac9b3ee5c
Re-export utils from Starlette (#1064)
*  Re-export main features used from Starlette to simplify developer's code

* ♻️ Refactor Starlette exports

* ♻️ Refactor tutorial examples to use re-exported utils from Starlette

* 📝 Add examples for all middlewares

* 📝 Add new docs for middlewares

* 📝 Add examples for custom responses

* 📝 Extend docs for custom responses

* 📝 Update docs and add notes explaining re-exports from Starlette everywhere

* 🍱 Update screenshot for HTTP status

* 🔧 Update MkDocs config with new content

* ♻️ Refactor tests to use re-exported utils from Starlette

*  Re-export WebSocketDisconnect from Starlette for tests

*  Add extra tests for extra re-exported middleware

*  Add tests for re-exported responses from Starlette

*  Add docs about mounting WSGI apps

*  Add Flask as a dependency to test WSGIMiddleware

*  Test WSGIMiddleware example
2020-03-01 21:49:20 +01:00

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Markdown

You probably read before that you can set a default [Response Status Code](../tutorial/response-status-code.md){.internal-link target=_blank}.
But in some cases you need to return a different status code than the default.
## Use case
For example, imagine that you want to return an HTTP status code of "OK" `200` by default.
But if the data didn't exist, you want to create it, and return an HTTP status code of "CREATED" `201`.
But you still want to be able to filter and convert the data you return with a `response_model`.
For those cases, you can use a `Response` parameter.
## Use a `Response` parameter
You can declare a parameter of type `Response` in your *path operation function* (as you can do for cookies and headers).
And then you can set the `status_code` in that *temporal* response object.
```Python hl_lines="1 9 12"
{!./src/response_change_status_code/tutorial001.py!}
```
And then you can return any object you need, as you normally would (a `dict`, a database model, etc).
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`.
You can also declare the `Response` parameter in dependencies, and set the status code in them. But have in mind that the last one to be set will win.