Up to here, everything would work as normally.

But then, when you open the integrated docs UI (the frontend), it would expect to get the OpenAPI schema at `/openapi.json`, instead of `/api/v1/openapi.json`.

This will be the main point of interaction to create all your API.

### Step 3: create a *path operation*

#### Path

"Path" here refers to the last part of the URL starting from the first `/`.

So, in a URL like:

```
https://example.com/items/foo
```

...the path would be:

```
/items/foo
```

!!! info
    A "path" is also commonly called an "endpoint" or a "route".

    So let's focus on the main cases, where it could crash entirely in some particular cases **in the future**, and it still makes sense to restart it.

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

So, what we will do next is add the code to document how that *external API* should look like to receive the callback from *your API*.

**FastAPI** is fully compatible with (and based on) <a href="https://www.starlette.io/" class="external-link" target="_blank"><strong>Starlette</strong></a>. So, any additional Starlette code you have, will also work.

`FastAPI` is actually a sub-class of `Starlette`. So, if you already know or use Starlette, most of the functionality will work the same way.

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

So, a request with a content type of `text/plain` containing JSON data would be accepted and the JSON data would be extracted.

## `fastapi dev`

When you run `fastapi dev`, it will run on development mode.

By default, it will have **auto-reload** enabled, so it will automatically reload the server when you make changes to your code. This is resource intensive and could be less stable than without it, you should only use it for development.