# Multiple sessions

Open and manage independent server-side sessions with the Mojo SDK.

A session is an independent, server-side context for authentication and session variables. Over a stateful WebSocket connection, the Mojo SDK can open several sessions on a single connection and address each one separately.

> [!NOTE]
> Sessions are a stateful feature provided by the WebSocket transport. WebSocket support is rolling out. On the HTTP transport, the engine reports `sessions=False` and the SDK raises an `UnsupportedFeatureError`.

## Opening a session

`new_session()` attaches a new session and returns a handle scoped to it. The handle exposes `use()`, `query()`, `set_string()`, `unset()`, `begin_transaction()`, and `close_session()`.

```python
var session = client.new_session()
session.use("test", "test")
var resp = session.query("SELECT * FROM person;")
session.close_session()
```

## Attaching and detaching

For lower-level control, `attach()` returns a session id you can pass to other calls, and `detach()` releases it.

```python
var session_id = client.attach()
var resp = client.query("SELECT * FROM person;", session=Optional(session_id))
client.detach(session_id)
```

`sessions()` lists the active sessions on the connection.

Most calls on the client, including `query`, `create`, and the auth methods, accept an optional `session` argument so you can target a specific session without a handle.