# Cookie Parameters

You can define Cookie parameters the same way you define `Query` and `Path` parameters.

## Import `Cookie`

First import `Cookie`:

```python
from typing import Annotated

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Annotated[str | None, Cookie()] = None):
    return {"ads_id": ads_id}
```

## Declare `Cookie` parameters

Then declare the cookie parameters using the same structure as with `Path` and `Query`.

You can define the default value as well as all the extra validation or annotation parameters:

```python
from typing import Annotated

from fastapi import Cookie, FastAPI

app = FastAPI()


@app.get("/items/")
async def read_items(ads_id: Annotated[str | None, Cookie()] = None):
    return {"ads_id": ads_id}
```

:::callout{intent="note" title="Technical Details"}
`Cookie` is a "sister" class of `Path` and `Query`. It also inherits from the same common `Param` class.

But remember that when you import `Query`, `Path`, `Cookie` and others from `fastapi`, those are actually functions that return special classes.
:::

:::callout{intent="note"}
To declare cookies, you need to use `Cookie`, because otherwise the parameters would be interpreted as query parameters.
:::

:::callout{intent="note"}
Have in mind that, as **browsers handle cookies** in special ways and behind the scenes, they **don't** easily allow **JavaScript** to touch them.

If you go to the **API docs UI** at `/docs` you will be able to see the **documentation** for cookies for your _path operations_.

But even if you **fill the data** and click "Execute", because the docs UI works with **JavaScript**, the cookies won't be sent, and you will see an **error** message as if you didn't write any values.
:::

## Recap

Declare cookies with `Cookie`, using the same common pattern as `Query` and `Path`.

## Related pages

- [About](./about-index.md)
- [Advanced User Guide](./advanced-user-guide-index.md)
- [Deployment](./deployment-index.md)
- [FastAPI](./fastapi-index.md)
- [FastAPI Docs](../index.md)
- [Features](./features-index.md)
- [How To - Recipes](./how-to-recipes-index.md)
- [Learn](./learn-index.md)
- [More](./more-index.md)
- [OpenAPI](./openapi-index.md)

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