Changelog

New Workflows API, Telnyx Phone Number Support, Voice Options, and much more

1. Workflows Replace Blocks: The API has migrated from blocks to workflows with new /workflow endpoints. Introduction to Workflows You can now use UpdateWorkflowDTO where conversation components (Say, Gather, ApiRequest, Hangup, Transfer nodes) are explicitly connected via edges to create directed conversation flows.

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{
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  "name": "Customer Support Workflow",
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  "nodes": [
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    {
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      "id": "greeting",
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      "type": "Say",
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      "text": "Hello, welcome to customer support. Do you need help with billing or technical issues?"
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    },
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    {
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      "id": "menu",
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      "type": "Gather",
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      "options": ["billing", "technical", "other"]
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    },
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    {
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      "id": "billing",
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      "type": "Say",
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      "text": "I'll connect you with our billing department."
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    },
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    {
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      "id": "technical",
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      "type": "Say",
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      "text": "I'll connect you with our technical support team."
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    },
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    {
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      "id": "transfer_billing",
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      "type": "Transfer",
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      "destination": {
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        "type": "number",
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        "number": "+1234567890"
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      }
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    },
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    {
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      "id": "transfer_technical",
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      "type": "Transfer",
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      "destination": {
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        "type": "number",
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        "number": "+1987654321"
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      }
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    }
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  ],
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  "edges": [
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    {
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      "from": "greeting",
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      "to": "menu"
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    },
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    {
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      "from": "menu",
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      "to": "billing",
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      "condition": {
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        "type": "logic",
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        "liquid": "{% if input == 'billing' %} true {% endif %}"
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      }
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    },
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    {
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      "from": "menu",
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      "to": "technical",
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      "condition": {
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        "type": "logic",
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        "liquid": "{% if input == 'technical' %} true {% endif %}"
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      }
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    },
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    {
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      "from": "billing",
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      "to": "transfer_billing"
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    },
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    {
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      "from": "technical",
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      "to": "transfer_technical"
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    }
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  ]
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}

2. Telnyx Phone Number Support: Telnyx is now available as a phone number provider alongside Twilio and Vonage.

   • Use the TelnyxPhoneNumber, CreateTelnyxPhoneNumberDTO, and UpdateTelnyxPhoneNumberDTO schemas with /phone-number endpoints to create and update Telnyx phone numbers.
   • The Call.phoneCallProviderId now includes Telnyx’s callControlId alongside Twilio’s callSid and Vonage’s conversationUuid.

3. New Voice Options:

   • Vapi Voices: New Vapi voices - Elliot, Rohan, Lily, Savannah, and Hana
   • Hume Voice: New provider with octave model and customizable voice settings
   • Neuphonic Voice: New provider with neu_hq (higher quality) and neu_fast (faster) models

4. New Cerebras Model: CerebrasModel Supports llama3.1-8b and llama-3.3-70b models

5. Enhanced Transcription:

   • New Providers: ElevenLabs and Speechmatics transcribers now available.
   • DeepgramTranscriber Numerals: New numerals option converts spoken numbers to digits (e.g., “nine-seven-two” → “972”)

6. Improved Voicemail Detection: You can now use multiple provider implementations for assistant.voicemailDetection (Google, OpenAI, Twilio). OpenAI implementation allows configuring detection duration (5-60 seconds, default: 15).

7. Smart Endpointing Upgrade: Now supports LiveKit as an alternative to Vapi’s custom-trained model in StartSpeakingPlan.smartEndpointingEnabled. LiveKit only supports English but may offer different endpointing characteristics.

8. Observability with Langfuse: New assistant.observabilityPlan property allows integration with Langfuse for tracing and monitoring of assistant calls. Configure with LangfuseObservabilityPlan.

9. More Credential Support: Added support for Cerebras, Google, Hume, InflectionAI, Mistral, Trieve, and Neuphonic credentials in assistant.credentials