This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant" { #second-dependency-dependable-and-dependant }

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

///

### Import `Depends` { #import-depends }

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[3] *}

### Declare the dependency, in the "dependant" { #declare-the-dependency-in-the-dependant }

The same way you use `Body`, `Query`, etc. with your *path operation function* parameters, use `Depends` with a new parameter:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[13,18] *}

<img src="/img/async/concurrent-burgers/concurrent-burgers-04.png" class="illustration">

Pendant que vous attendez, vous allez choisir une table avec votre crush 😍, vous discutez avec votre crush 😍 pendant un long moment (les burgers étant "magnifiques" ils sont très longs à préparer ✨🍔✨).

It will always have the security scopes declared in the current `Security` dependencies and all the dependants for **that specific** *path operation* and **that specific** dependency tree.

* ⬆ Bump dawidd6/action-download-artifact from 2.9.0 to 2.21.1. PR [#5130](https://github.com/tiangolo/fastapi/pull/5130) by [@dependabot[bot]](https://github.com/apps/dependabot).
* ⬆ Bump actions/setup-python from 2 to 4. PR [#5129](https://github.com/tiangolo/fastapi/pull/5129) by [@dependabot[bot]](https://github.com/apps/dependabot).

# Conditional OpenAPI { #conditional-openapi }

If you needed to, you could use settings and environment variables to configure OpenAPI conditionally depending on the environment, and even disable it entirely.

## About security, APIs, and docs { #about-security-apis-and-docs }

Hiding your documentation user interfaces in production *shouldn't* be the way to protect your API.

## Deployment Strategies { #deployment-strategies }

There are several ways to do it depending on your specific use case and the tools that you use.

You could **deploy a server** yourself using a combination of tools, you could use a **cloud service** that does part of the work for you, or other possible options.

When using **Pydantic v2**, the generated OpenAPI is a bit more exact and **correct** than before. 😎

In fact, in some cases, it will even have **two JSON Schemas** in OpenAPI for the same Pydantic model, for input and output, depending on if they have **default values**.

Let's see how that works and how to change it if you need to do that.

## Pydantic Models for Input and Output { #pydantic-models-for-input-and-output }

Depending on your use case, you might prefer to use a different library, but if you asked me, I would probably suggest you try **Strawberry**.

Here's a small preview of how you could integrate Strawberry with FastAPI:

But you should first read the **Tutorial - User Guide** (what you are reading right now).