target="_blank">Verwenden Sie dafür das Präfix 'X-'</a>.

    Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen soll, müssen Sie sie zu Ihrer CORS-Konfigurationen ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) hinzufügen, indem Sie den Parameter `expose_headers` verwenden, der in der <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette-CORS-Dokumentation</a> dokumentiert...

## Available versions

You can see the available versions (e.g. to check what is the current latest) in the [Release Notes](../release-notes.md){.internal-link target=_blank}.

## About versions

Following the Semantic Versioning conventions, any version below `1.0.0` could potentially add breaking changes.

    But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) using the parameter `expose_headers` documented in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>.

!!! note "Technical Details"

```
go run client-grants.go -cid PoEgXP6uVO45IsENRngDXj5Au5Ya -csec eKsw6z8CtOJVBtrOWvhRWL4TUCga

##### Credentials
{
 "accessKey": "IRBLVDGN5QGMDCMO1X8V",

## Versions disponibles

Vous pouvez consulter les versions disponibles (par exemple, pour vérifier quelle est la dernière version en date) dans les [Notes de version](../release-notes.md){.internal-link target=_blank}.

## À propos des versions

Suivant les conventions de versionnage sémantique, toute version inférieure à `1.0.0` peut potentiellement ajouter
des changements non rétrocompatibles.

    请记住可以 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">用'X-' 前缀</a>添加专有自定义请求头.

    但是如果你想让浏览器中的客户端看到你的自定义请求头, 你需要把它们加到 CORS 配置 ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) 的 `expose_headers` 参数中,在 <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>文档中.

!!! note "技术细节"

!!! tip
    If you want to call `async` functions in your tests apart from sending requests to your FastAPI application (e.g. asynchronous database functions), have a look at the [Async Tests](../advanced/async-tests.md){.internal-link target=_blank} in the advanced tutorial.

## Separating tests

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

# Templating – `Jinja2Templates`

Sie können die `Jinja2Templates`-Klasse verwenden, um Jinja-Templates zu rendern.

Lesen Sie mehr darüber in der [FastAPI-Dokumentation zu Templates](../advanced/templates.md).

Sie können die Klasse direkt von `fastapi.templating` importieren:

```python
from fastapi.templating import Jinja2Templates
```

🚥 👆 ⚙️ 🙆 🎏 🧰 🛠️ 👆 👷‍♂, 💖 🎶, Pipenv, ⚖️ 🎏, 👫 🌐 ✔️ 🌌 👈 👆 💪 ⚙️ 🔬 🎯 ⏬ 👆 📦.

## 💪 ⏬

👆 💪 👀 💪 ⏬ (✅ ✅ ⚫️❔ ⏮️ 📰) [🚀 🗒](../release-notes.md){.internal-link target=_blank}.

## 🔃 ⏬

📄 ⚛ 🛠️ 🏛, 🙆 ⏬ 🔛 `1.0.0` 💪 ⚠ 🚮 💔 🔀.

FastAPI ⏩ 🏛 👈 🙆 "🐛" ⏬ 🔀 🐛 🔧 & 🚫-💔 🔀.

!!! tip
     "🐛" 🏁 🔢, 🖼, `0.2.3`, 🐛 ⏬ `3`.

# Advanced Middleware

In the main tutorial you read how to add [Custom Middleware](../tutorial/middleware.md){.internal-link target=_blank} to your application.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares