# Extending OpenAPI

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

* Der *Pfad* kann einen <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md#key-expression" class="external-link" target="_blank">OpenAPI-3-Ausdruck</a> enthalten (mehr dazu weiter unten), wo er Variablen mit Parametern und Teilen des ursprünglichen Requests verwenden kann, der an *Ihre API* gesendet wurde.

### OpenID (não "OpenID Connect")

Houve também uma especificação “OpenID”. Ela tentou resolver a mesma coisa que a **OpenID Connect**, mas não baseada em OAuth2.

Então, ela foi um sistema adicional completo.

Ela não é muito popular ou usada nos dias de hoje.

## OpenAPI

OpenAPI (anteriormente conhecido como Swagger) é a especificação aberta para a criação de APIs (agora parte da Linux Foundation).

**FastAPI** é baseado no **OpenAPI**.

👉 📄 👆 🔜 👀 ❔.

## 😐 🛠️

😐 (🔢) 🛠️, ⏩.

`FastAPI` 🈸 (👐) ✔️ `.openapi()` 👩‍🔬 👈 📈 📨 🗄 🔗.

🍕 🈸 🎚 🏗, *➡ 🛠️* `/openapi.json` (⚖️ ⚫️❔ 👆 ⚒ 👆 `openapi_url`) ®.

⚫️ 📨 🎻 📨 ⏮️ 🏁 🈸 `.openapi()` 👩‍🔬.

🔢, ⚫️❔ 👩‍🔬 `.openapi()` 🔨 ✅ 🏠 `.openapi_schema` 👀 🚥 ⚫️ ✔️ 🎚 & 📨 👫.

🚥 ⚫️ 🚫, ⚫️ 🏗 👫 ⚙️ 🚙 🔢 `fastapi.openapi.utils.get_openapi`.

& 👈 🔢 `get_openapi()` 📨 🔢:

		chmod +x mc
fi

mc -v

# Start openid server
(
	cd ./minio-iam-testing
	make docker-images
	make docker-run
	cd -
)

(minio server --address :22000 --console-address :10000 http://localhost:22000/tmp/openid{1...4} 2>&1 >/tmp/server.log) &
./mc ready myminio
./mc mb myminio/test-bucket
./mc cp /etc/hosts myminio/test-bucket

./mc idp openid add myminio \

# OpenAPI erweitern

In einigen Fällen müssen Sie möglicherweise das generierte OpenAPI-Schema ändern.

In diesem Abschnitt erfahren Sie, wie.

## Der normale Vorgang

Der normale (Standard-)Prozess ist wie folgt.

Eine `FastAPI`-Anwendung (-Instanz) verfügt über eine `.openapi()`-Methode, von der erwartet wird, dass sie das OpenAPI-Schema zurückgibt.

## Conditional OpenAPI from settings and env vars

You can easily use the same Pydantic settings to configure your generated OpenAPI and the docs UIs.

For example:

{* ../../docs_src/conditional_openapi/tutorial001.py hl[6,11] *}

Here we declare the setting `openapi_url` with the same default of `"/openapi.json"`.

And then we use it when creating the `FastAPI` app.

# Separate OpenAPI Schemas for Input and Output or Not

When using **Pydantic v2**, the generated OpenAPI is a bit more exact and **correct** than before. 😎

In fact, in some cases, it will even have **two JSON Schemas** in OpenAPI for the same Pydantic model, for input and output, depending on if they have **default values**.

Let's see how that works and how to change it if you need to do that.

## Pydantic Models for Input and Output

## Documenting webhooks with **FastAPI** and OpenAPI

With **FastAPI**, using OpenAPI, you can define the names of these webhooks, the types of HTTP operations that your app can send (e.g. `POST`, `PUT`, etc.) and the request **bodies** that your app would send.

* The *path* can contain an <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md#key-expression" class="external-link" target="_blank">OpenAPI 3 expression</a> (see more below) where it can use variables with parameters and parts of the original request sent to *your API*.

### The callback path expression