# Templates

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `jinja2`:

<div class="termy">

The same example from above, returning an `HTMLResponse`, could look like:

```Python hl_lines="2  7  19"
{!../../docs_src/custom_response/tutorial003.py!}
```

/// warning

                                            {
                                                "name": "Baz",
                                                "price": "thirty five point four",
                                            },
                                        ],
                                    }
                                )
                                | IsDict(

One particular advantage that is not necessarily obvious is that you can **generate clients** (sometimes called <abbr title="Software Development Kits">**SDKs**</abbr> ) for your API, for many different **programming languages**.

## OpenAPI Client Generators

There are many tools to generate clients from **OpenAPI**.

    <div class="item">
      <a title="CryptAPI: Your easy to use, secure and privacy oriented payment gateway." style="display: block; position: relative;" href="https://cryptapi.io/" target="_blank">
        <span class="sponsor-badge">sponsor</span>
        <img class="sponsor-image" src="/img/sponsors/cryptapi-banner.svg" />
      </a>
    </div>
    <div class="item">

and style in order to keep the code as readable as possible. Please also make
sure your code compiles by running `./gradlew check`. Checkstyle failures
during compilation indicate errors in your style and can be viewed in the
`checkstyle-result.xml` file.

Some general advice

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code

     * href="https://github.com/google/guava#adding-guava-to-your-build">Adding Guava to your
     * build</a>.)
     *
     * <p>Be careful when targeting an older SDK than you are building against (most commonly when
     * building for Android): Ensure that any object you pass implements the interface not just in
     * your current SDK version but also at the oldest version you support. For example, <a

          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and

          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and