!!! tip
    It's probably better to use dependencies with `yield` when they are enough for the use case.

!!! info
    Dependencies with `yield` were added recently to **FastAPI**.

  - author: Louis Guitton
    author_link: https://twitter.com/louis_guitton
    link: https://guitton.co/posts/fastapi-monitoring/
    title: How to monitor your FastAPI service
  - author: Precious Ndubueze
    author_link: https://medium.com/@gabbyprecious2000
    link: https://medium.com/@gabbyprecious2000/creating-a-crud-app-with-fastapi-part-one-7c049292ad37
    title: Creating a CRUD App with FastAPI (Part one)

So, it was a complete additional system.

It is not very popular or used nowadays.

## OpenAPI

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.