---

## Install FastAPI { #install-fastapi }

The first step is to install FastAPI.

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and then **install FastAPI**:

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

/// note

## `fastapi-slim`

⚠️ Do not install this package. ⚠️

This package, `fastapi-slim`, does nothing other than depend on `fastapi`.

All the functionality has been integrated into `fastapi`.

The only reason this package exists is as a migration path for old projects that used to depend on `fastapi-slim`, so that they can get the latest version of `fastapi`.

You **should not** install this package.

Install instead:

RUN Add-Content -Path C:\tools\msys64\etc\pacman.d\mirrorlist.msys -Value 'SigLevel = Never'

# Install pacman packages.
RUN C:\tools\msys64\usr\bin\bash.exe -lc \
  'pacman --noconfirm -Syy curl git patch vim unzip zip'

# Install multiple Pythons, but only add one of them to PATH.
RUN function Install-Python { \
        param( \
            [string]$version, \
            [int]$prependPath \
        ) \

            pyproject.toml
            uv.lock
      - name: Install Dependencies
        run: uv sync --no-dev --group tests --extra all
      - name: Ensure that we have the lowest supported Pydantic version
        if: matrix.uv-resolution == 'lowest-direct'
        run: uv pip install "pydantic==2.9.0"
      - name: Install Starlette from source
        if: matrix.starlette-src == 'starlette-git'

## Using `TestClient` { #using-testclient }

/// info

To use `TestClient`, first install [`httpx`](https://www.python-httpx.org).

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and then install it, for example:

```console
$ pip install httpx
```

///

Import `TestClient`.

Create a `TestClient` by passing your **FastAPI** application to it.

## Install `PyJWT` { #install-pyjwt }

We need to install `PyJWT` to generate and verify the JWT tokens in Python.

Make sure you create a [virtual environment](../../virtual-environments.md), activate it, and then install `pyjwt`:

<div class="termy">

```console
$ pip install pyjwt

---> 100%
```

</div>

/// info

```gitignore
*
```

///

## Install Packages { #install-packages }

After activating the environment, you can install packages in it.

/// tip

Do this **once** when installing or upgrading the packages your project needs.

If you need to upgrade a version or add a new package you would **do this again**.

///

### Install Packages Directly { #install-packages-directly }

    tar zxf - google-cloud-sdk && \
    google-cloud-sdk/install.sh --quiet && \
    ln -s /google-cloud-sdk/bin/gcloud /usr/bin/gcloud
ENV PATH="$PATH:/google-cloud-sdk/bin/:/usr/local/cuda/bin/"

# Download and install patchelf v0.18.0 from GitHub. The default Ubuntu focal
# packages only provide the "0.10-2build1" version. We use patchelf to manipulate

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

## Install dependencies { #install-dependencies }

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and install `jinja2`:

<div class="termy">

```console
$ pip install jinja2

---> 100%
```

</div>

## Using `Jinja2Templates` { #using-jinja2templates }

You can use **Pydantic models** to declare **form fields** in FastAPI.

/// info

To use forms, first install [`python-multipart`](https://github.com/Kludex/python-multipart).

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

/// note

This is supported since FastAPI version `0.113.0`. 🤓