The contents are **encrypted**, even though they are being sent with the **HTTP protocol**.

It is a common practice to have **one program/HTTP server** running on the server (the machine, host, etc.) and **managing all the HTTPS parts**: receiving the **encrypted HTTPS requests**, sending the **decrypted HTTP requests** to the actual HTTP application running in the same server (the **FastAPI** application, in this case), take the **HTTP response** from the application, **encrypt it** using...

          // Otherwise, an F -> T cycle will end up resolving both F and T
          // nondeterministically to either F or T.
          for (Type x = arg; x != null; x = mappings.remove(TypeVariableKey.forLookup(x))) {}
          return;
        }
      }
      mappings.put(var, arg);
    }
  }

  // This is needed when resolving types against a context with wildcards
  // For example:

# Lifespan Events { #lifespan-events }

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

          // Otherwise, an F -> T cycle will end up resolving both F and T
          // nondeterministically to either F or T.
          for (Type x = arg; x != null; x = mappings.remove(TypeVariableKey.forLookup(x))) {}
          return;
        }
      }
      mappings.put(var, arg);
    }
  }

  // This is needed when resolving types against a context with wildcards
  // For example:

* `swagger_js_url`: the URL where the HTML for your Swagger UI docs can get the **JavaScript** file. **This is the one that your own app is now serving**.
* `swagger_css_url`: the URL where the HTML for your Swagger UI docs can get the **CSS** file. **This is the one that your own app is now serving**.

And similarly for ReDoc...

{* ../../docs_src/custom_docs_ui/tutorial002.py hl[2:6,14:22,25:27,30:36] *}

/// tip

Just keep in mind that when you read "server" in general, it could refer to one of those two things.

When referring to the remote machine, it's common to call it **server**, but also **machine**, **VM** (virtual machine), **node**. Those all refer to some type of remote machine, normally running Linux, where you run programs.

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

 link: https://www.tutlinks.com/deploy-fastapi-on-azure/ title: Deploy FastAPI on Azure App Service - author: Davide Fiocco author_link: https://github.com/davidefiocco link: https://davidefiocco.github.io/streamlit-fastapi-ml-serving/ title: Machine learning model serving in Python using FastAPI and streamlit - author: Netflix author_link: https://netflixtechblog.com/ link: https://netflixtechblog.com/introducing-dispatch-da4b8a2a8072 title: Introducing Dispatch - author: Stavros Korokithakis author_link:...

{* ../../docs_src/path_params/tutorial003.py hl[6,11] *}

Otherwise, the path for `/users/{user_id}` would match also for `/users/me`, "thinking" that it's receiving a parameter `user_id` with a value of `"me"`.

Similarly, you cannot redefine a path operation:

{* ../../docs_src/path_params/tutorial003b.py hl[6,11] *}

Run the server with:

<div class="termy">

```console
$ fastapi dev main.py

 ╭────────── FastAPI CLI - Development mode ───────────╮
 │                                                     │
 │  Serving at: http://127.0.0.1:8000                  │
 │                                                     │
 │  API docs: http://127.0.0.1:8000/docs               │
 │                                                     │