# web.session

## Function

Read and save the current request Session object.

## Syntax

```bt
web.session
```

## Parameters

No parameters.

## Return value

| Type | Description |
| ------ | ------ |
| Object | Returns the Session object of the current request. |

## Object structure

| Field | Type | Description |
| ------ | ------ | ------ |
| Any Session key name | Any | The value saved in the current Session. Supports JSON expressible String, Int, Float, Bool, Array, Object, and Null; when the key does not exist, the read result is Empty. |

## Example

```bt
web.session.user = 'BT'
result = web.session.user

// Output: BT
print result
```

## Notes

- The bottom layer of Session saves JSON strings in __bt_session_json.
- At the end of the request, `web.session` will be serialized into JSON and saved.
- Non-JSON basic values such as Fs, functions, and class instances will be written to the Session as strings. It is not recommended to directly save such runtime objects.