Send control command to active call

Send real-time commands to an active call. The call must be in "in-progress" status.

⚠️ IMPORTANT: xAI Realtime Model Limitations

Call control has significant limitations when using xAI Realtime (grok-realtime-v1) due to its speech-to-speech architecture:

❌ inject-context: Limited effectiveness - context may not influence responses reliably

❌ say: Does not work reliably - commands often timeout or fail to trigger speech

✅ end-call: Works reliably

⚠️ transfer: Partial support - announcement may not work, but transfer executes

Why the limitations?
xAI Realtime is an end-to-end audio model that processes speech directly without intermediate text. It expects continuous audio input and cannot reliably respond to text-based control commands mid-conversation.

Recommendation:
If you need full call control support (inject-context, say, transfer with announcements), use the traditional pipeline:

Provider: openai with gpt-4o or gpt-4o-mini

STT: Deepgram (nova-3-general)

TTS: ElevenLabs or OpenAI TTS

Result: All control commands work reliably

Command Types:

inject-context: Silently add information to the agent's context (traditional models only)

say: Make the agent speak specific text (traditional models only)

end-call: End the call with an optional final message (works with all models)

transfer: Transfer the call to another destination (partial xAI Realtime support)

Use Cases:

SMS verification: Inject received codes into the conversation

CRM integration: Add customer context mid-call

Human escalation: Transfer to a live agent

Emergency end: Gracefully terminate problematic calls

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

curl --location --request POST 'https://api.hmsovereign.com/api/v1/calls//control' \ --header 'Authorization: Bearer <token>' \ --header 'Content-Type: application/json' \ --data-raw '{ "type": "inject-context", "content": "The customer has been verified as John Smith, account #12345", "trigger_response": true }'

Send control command to active call

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