The build tree state is managed by the `BuildTreeState` class.
An instance is created at the start of a build execution and discarded at the end of the execution.

### Build state

The "build state" holds the state for a build within the build definition for a single build execution, and is contained by the build tree state.

The build state is managed by the `BuildState` class.

* Fix serialization of errors for exotic Pydantic types. PR [#748](https://github.com/tiangolo/fastapi/pull/748) by [@dmontagu](https://github.com/dmontagu).

## 0.44.0

* Add GitHub action [Issue Manager](https://github.com/tiangolo/issue-manager). PR [#742](https://github.com/tiangolo/fastapi/pull/742).
* Fix typos in docs. PR [734](https://github.com/tiangolo/fastapi/pull/734) by [@bundabrg](https://github.com/bundabrg).

# 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