> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blaxel.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# WebSocket connection timeouts and the 15-minute limit

> Keep long-running sandbox WebSocket connections reliable by handling the 15-minute idle timeout, reconnection, standby, and ping-pong traffic.

Sandbox WebSocket connections have a 15-minute idle timeout. If no data flows through a connection for 15 minutes, Blaxel closes it and transitions the sandbox to standby.

## Timeout behavior

When a WebSocket connection reaches the 15-minute idle limit, it disconnects automatically. Your client must reconnect when this happens.

## Automatic reconnection

For processes that run longer than 15 minutes, reconnect automatically after the existing connection closes. Reconnection is typically seamless and fast enough for most use cases.

## Sandbox keep-alive

By default, sandboxes enter standby after a few seconds of inactivity to save resources. You can keep a sandbox running after launching a process even when no active client connection exists.

This behavior is useful for a server that must continue running while it is not serving requests. Configure it with the [sandbox keep-alive settings](/Sandboxes/Standby-control).

## Ping-pong traffic

To prevent an idle connection from timing out:

* Send data actively between the client and server
* Exchange regular ping-pong messages to keep the connection active

<CardGroup cols={2}>
  <Card title="Standby control" href="/Sandboxes/Standby-control">
    Configure standby behavior and keep-alive settings.
  </Card>

  <Card title="Sandbox sessions" href="/Sandboxes/Sessions">
    Learn how to manage interactive sandbox sessions.
  </Card>
</CardGroup>


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