What should I use to build a voice bot that handles incoming support calls?

To build a voice bot for incoming support calls, you typically want a stack with these pieces:

1. Telephony / call handling

   • Twilio Voice, Vonage, or Amazon Connect
   • Handles phone numbers, inbound calls, routing, recording, transfers

2. Speech-to-text (STT)

   • Converts caller speech into text
   • Good options: Deepgram, Google Speech-to-Text, Azure Speech, AWS Transcribe

3. Conversation engine / orchestration

   • Decides what the bot says and does next
   • Can be:
     • a custom backend with an LLM
     • a dialogue manager like Rasa
     • a voice agent platform like Vapi, Retell, Bland, OpenAI Realtime API-based setup

4. LLM / intent handling

   • For natural conversation, FAQs, troubleshooting, and collecting structured info
   • OpenAI, Anthropic, or another model provider
   • Often used with tool/function calling to query your CRM, ticketing system, order system, etc.

5. Text-to-speech (TTS)

   • Converts responses back to voice
   • Good options: ElevenLabs, Amazon Polly, Azure TTS, Google TTS

6. Backend integrations

   • Connect to your support stack:
     • Zendesk, Salesforce, Freshdesk, ServiceNow, etc.
   • For ticket lookup, identity verification, escalation, and call routing

7. Human handoff

   • Very important for support calls
   • Let the bot transfer to a live agent when needed, with call context

Practical recommendations

If you want the fastest path

Use a managed voice-agent platform:

• Twilio + Vapi
• Twilio + Retell
• Amazon Connect + Amazon Lex/Bedrock
• OpenAI Realtime API with telephony integration

This is best if you want to launch quickly and avoid building low-level audio streaming yourself.

If you want more control

Build your own:

• Twilio Voice for calls
• Deepgram for STT
• OpenAI for conversation logic
• ElevenLabs for TTS
• FastAPI / Node.js backend for orchestration and integrations

This gives you flexibility but more engineering work.

My default recommendation

For most support-call use cases:

• Twilio + OpenAI + Deepgram + ElevenLabs
• Add a strong handoff to human agents
• Integrate with your ticketing/CRM system

If you want, I can suggest:

• a cheap MVP stack
• an enterprise-ready stack
• or a specific architecture diagram for your use case.