This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event

Zum Beispiel bietet **FastAPI** selbst eine alternative API-Dokumentation (verwendet ReDoc), welche Sie unter <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a> einsehen können:

* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <a href="https://github.com/OAI/OpenAPI-Specification" class="external-link" target="_blank">OpenAPI</a> (previously known as Swagger) and <a href="https://json-schema.org/" class="external-link" target="_blank">JSON Schema</a>.

<small>* estimation based on tests conducted by an internal development team, building production applications.</small>

///

## Дополнительная информация { #more-info }

Для более глубокого изучения темы воспользуйтесь документацией Starlette:

* <a href="https://www.starlette.dev/websockets/" class="external-link" target="_blank">The `WebSocket` class</a>.

* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <a href="https://github.com/OAI/OpenAPI-Specification" class="external-link" target="_blank">OpenAPI</a> (previously known as Swagger) and <a href="https://json-schema.org/" class="external-link" target="_blank">JSON Schema</a>.

<small>* estimation based on tests conducted by an internal development team, building production applications.</small>

{* ../../docs_src/path_params/tutorial001.py hl[6:7] *}

La valeur du paramètre `item_id` sera transmise à la fonction dans l'argument `item_id`.

Donc, si vous exécutez cet exemple et allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>,

Les captures d'écrans précédentes ont été prises sur <a href="https://code.visualstudio.com" class="external-link" target="_blank">Visual Studio Code</a>.

Mais vous auriez le même support de l'éditeur avec <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a> et la majorité des autres éditeurs de code Python.

<img src="/img/tutorial/body/image05.png">

There were even some changes to Pydantic itself to support this.

The previous screenshots were taken with <a href="https://code.visualstudio.com" class="external-link" target="_blank">Visual Studio Code</a>.

But you would get the same editor support with <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a> and most of the other Python editors:

<img src="/img/tutorial/body/image05.png">

/// tip

* <a href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css" class="external-link" target="_blank">`swagger-ui.css`</a>

А **ReDoc** использует файл:

* <a href="https://cdn.jsdelivr.net/npm/redoc@2/bundles/redoc.standalone.js" class="external-link" target="_blank">`redoc.standalone.js`</a>

* <a href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" class="external-link" target="_blank">Render</a>