You can create production applications with **FastAPI** right now (and you have probably been doing it for some time), you just have to make sure that you use a version that works correctly with the rest of your code.

## Pin your `fastapi` version

Depending on your use case, you might prefer to use a different library, but if you asked me, I would probably suggest you try **Strawberry**.

Here's a small preview of how you could integrate Strawberry with FastAPI:

```Python hl_lines="3  22  25-26"

        "purple":      "#ab47bd",
        "deep-purple": "#7e56c2",
        "indigo":      "#4051b5",
        "blue":        "#2094f3",
        "light-blue":  "#02a6f2",
        "cyan":        "#00bdd6",
        "teal":        "#009485",
        "green":       "#4cae4f",
        "light-green": "#8bc34b",
        "lime":        "#cbdc38",
        "yellow":      "#ffec3d",
        "amber":       "#ffc105",
        "orange":      "#ffa724",

## Separating tests

In a real application, you probably would have your tests in a different file.

And your **FastAPI** application might also be composed of several files/modules, etc.

### **FastAPI** app file

Let's say you have a file structure as described in [Bigger Applications](bigger-applications.md){.internal-link target=_blank}:

```
.

* Die Verschlüsselung der Verbindung erfolgt auf **TCP-Ebene**.
    * Das ist eine Schicht **unter HTTP**.
    * Die Handhabung von **Zertifikaten und Verschlüsselung** erfolgt also **vor HTTP**.
* **TCP weiß nichts über „<abbr title="Domäne, Bereich, Wirkungsraum">Domains</abbr>“**. Nur über IP-Adressen.
    * Die Informationen über die angeforderte **spezifische Domain** befinden sich in den **HTTP-Daten**.

# Development - Contributing

First, you might want to see the basic ways to [help FastAPI and get help](help-fastapi.md){.internal-link target=_blank}.

## Developing

If you already cloned the <a href="https://github.com/tiangolo/fastapi" class="external-link" target="_blank">fastapi repository</a> and you want to deep dive in the code, here are some guidelines to set up your environment.

### Virtual environment with `venv`

from typing import Dict

from fastapi import FastAPI

app = FastAPI()


@app.get("/keyword-weights/", response_model=Dict[str, float])
async def read_keyword_weights():

The client will get a **500 Internal Server Error** for that request, but the application will continue working for the next requests instead of just crashing completely.

### Bigger Errors - Crashes

Nevertheless, there might be cases where we write some code that **crashes the entire application** making Uvicorn and Python crash. 💥

## Sortieren Sie die Parameter, wie Sie möchten

!!! tip "Tipp"
    Wenn Sie `Annotated` verwenden, ist das folgende nicht so wichtig / nicht notwendig.

Nehmen wir an, Sie möchten den Query-Parameter `q` als erforderlichen `str` deklarieren.

* **Modify some DNS records**.
    * For this, the renewal program needs to support the APIs of the DNS provider, so, depending on the DNS provider you are using, this might or might not be an option.
* **Run as a server** (at least during the certificate acquisition process) on the public IP address associated with the domain.
    * As we said above, only one process can be listening on a specific IP and port.