### Other utility functions

Any other utility function that you call directly can be created with normal `def` or `async def` and FastAPI won't affect the way you call it.

This is in contrast to the functions that FastAPI calls for you: *path operation functions* and dependencies.

        val generatedTopLevelClassifiers = declarationGenerators
            .asSequence()
            .flatMap {
                // FIXME this function should be called only once during plugin's lifetime, so this usage is not really correct (2)
                it.getTopLevelClassIds()
            }
            .filter { it.packageFqName == packageFqName }
            .map { it.shortClassName }

    } else {
      eventListener.callEnd(this)
    }
    return result
  }

  /**
   * Remove this call from the connection's list of allocations. Returns a socket that the caller
   * should close.
   */
  internal fun releaseConnectionNoEvents(): Socket? {
    val connection = this.connection!!
    connection.lock.assertHeld()

    val calls = connection.calls

    {!> ../../../docs_src/path_operation_advanced_configuration/tutorial007_pv1.py!}
    ```

!!! info
    In Pydantic version 1 the method to get the JSON Schema for a model was called `Item.schema()`, in Pydantic version 2, the method is called `Item.model_json_schema()`.

# Python Types Intro

Python has support for optional "type hints" (also called "type annotations").

These **"type hints"** or annotations are a special syntax that allow declaring the <abbr title="for example: str, int, float, bool">type</abbr> of a variable.

By declaring types for your variables, editors and tools can give you better support.

The build state is managed by the `BuildState` class.
An instance is created for each build in the build definition, once per build execution and is discarded at the end of the execution. 

The build state also includes what is currently called the "Gradle state". The Gradle state is being merged into the build state and is mostly empty.

### Project state

Actually, all (or most) of the web frameworks work in this same way.

You never call those functions directly. They are called by your framework (in this case, **FastAPI**).

# FastAPI CLI

**FastAPI CLI** is a command line program `fastapi` that you can use to serve your FastAPI app, manage your FastAPI project, and more.

When you install FastAPI (e.g. with `pip install fastapi`), it includes a package called `fastapi-cli`, this package provides the `fastapi` command in the terminal.

To run your FastAPI app for development, you can use the `fastapi dev` command:

<div class="termy">

```console

Normally you use:

* `POST`: to create data.
* `GET`: to read data.
* `PUT`: to update data.
* `DELETE`: to delete data.

So, in OpenAPI, each of the HTTP methods is called an "operation".

We are going to call them "**operations**" too.

#### Define a *path operation decorator*

```Python hl_lines="6"
{!../../../docs_src/first_steps/tutorial001.py!}
```

### Async Context Manager

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

```Python hl_lines="1  13"
{!../../../docs_src/events/tutorial003.py!}
```