In many frameworks and systems just handling security and authentication takes a big amount of effort and code (in many cases it can be 50% or more of all the code written).

**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry?

    You could also use `from starlette.templating import Jinja2Templates`.

    **FastAPI** provides the same `starlette.templating` as `fastapi.templating` just as a convenience for you, the developer. But most of the available responses come directly from Starlette. The same with `Request` and `StaticFiles`.

## Writing templates

Then you can write a template at `templates/item.html` with, for example:

```jinja hl_lines="7"

### `Response`

The main `Response` class, all the other responses inherit from it.

You can return it directly.

It accepts the following parameters:

* `content` - A `str` or `bytes`.
* `status_code` - An `int` HTTP status code.
* `headers` - A `dict` of strings.

![editor support](https://fastapi.tiangolo.com/img/vscode-completion.png)

* in <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

## Origin

An origin is the combination of protocol (`http`, `https`), domain (`myapp.com`, `localhost`, `localhost.tiangolo.com`), and port (`80`, `443`, `8080`).

So, all these are different origins:

* `http://localhost`

🎏 🌌 👆 💪 ✔ 📨 🏷, 👆 💪 📣 🇺🇸🔍 👔 📟 ⚙️ 📨 ⏮️ 🔢 `status_code` 🙆 *➡ 🛠️*:

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* ♒️.

```Python hl_lines="6"
{!../../../docs_src/response_status_code/tutorial001.py!}
```

!!! note
    👀 👈 `status_code` 🔢 "👨‍🎨" 👩‍🔬 (`get`, `post`, ♒️). 🚫 👆 *➡ 🛠️ 🔢*, 💖 🌐 🔢 & 💪.

`status_code` 🔢 📨 🔢 ⏮️ 🇺🇸🔍 👔 📟.

!!! info

It is also built to work as a future reference.

So you can come back and see exactly what you need.

## Run the code

All the code blocks can be copied and used directly (they are actually tested Python files).

To run any of the examples, copy the code to a file `main.py`, and start `fastapi dev` with:

<div class="termy">

```console

& ⤴️ 👆 💪 ⚒ `status_code` 👈 *🔀* 📨 🎚.

```Python hl_lines="1  9  12"
{!../../../docs_src/response_change_status_code/tutorial001.py!}
```

& ⤴️ 👆 💪 📨 🙆 🎚 👆 💪, 👆 🛎 🔜 ( `dict`, 💽 🏷, ♒️).

& 🚥 👆 📣 `response_model`, ⚫️ 🔜 ⚙️ ⛽ & 🗜 🎚 👆 📨.

**FastAPI** 🔜 ⚙️ 👈 *🔀* 📨 ⚗ 👔 📟 (🍪 & 🎚), & 🔜 🚮 👫 🏁 📨 👈 🔌 💲 👆 📨, ⛽ 🙆 `response_model`.

client = TestClient(app)


def test_get_response():
    response = client.get("/a")
    assert response.status_code == 204, response.text
    assert "content-length" not in response.headers
    assert response.content == b""


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

!!! warning