### In production

In your production system, you probably have a frontend created with a modern framework like React, Vue.js or Angular.

And to communicate using WebSockets with your backend you would probably use your frontend's utilities.

Or you might have a native mobile application that communicates with your WebSocket backend directly, in native code.

Or you might have any other way to communicate with the WebSocket endpoint.

---

Specially useful when using `path` convertors, to take a whole path as a parameter, like `/some/url/{p:path}`. PR [#234](https://github.com/tiangolo/fastapi/pull/234) by [@euri10](https://github.com/euri10).

* Make default parameter utilities exported from `fastapi` be functions instead of classes (the new functions return instances of those classes). To be able to override the return types and fix `mypy` errors in FastAPI's users' code. Applies to `Path`, `Query`, `Header`, `Cookie`,...

## Dépendances facultatives

Utilisées par Pydantic:

* <a href="https://github.com/JoshData/python-email-validator" target="_blank"><code>email_validator</code></a> - pour la validation des adresses email.

Utilisées par Starlette :