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

> Connect app voice call through the Voice SDK integration. Use with the authentication and customer identity flow described in the app voice guide.

# Connect web call

See [Voice SDK integration](/phone/voice-sdk) for authentication, platform packages, routing, and preview availability.

The SDK calls this after joining and publishing microphone audio. Use `Authorization: Bearer <controlToken>` from call creation. Permanent API keys and media tokens are not accepted for call control.

Returns HTTP 200 with `{ "success": true }`. Repeated activation of an active call is safe. Expired or ended calls, missing microphone publication, and unavailable support return 409. A failed activation ends its reserved call; begin a new call attempt with a new request ID.