Leverage OpenAI's Realtime API with GPT-4o for voice agents that combine world-class language understanding with native audio processing. Get the reasoning power of GPT-4o in real-time voice conversations.
GPT-4o
Model Quality
400ms
E2E Latency
Multilingual
Language Support
Trusted by businesses worldwide
Every voice interaction is backed by GPT-4o's advanced reasoning capabilities, handling complex multi-step queries, nuanced requests, and ambiguous instructions with ease.
OpenAI Realtime API processes audio natively without separate STT/TTS pipelines, reducing latency and enabling more natural-sounding conversations.
Built-in function calling allows the voice agent to execute actions mid-conversation -- book appointments, query databases, update CRMs -- all through natural speech.
End-to-end response times that create fluid conversations. The native audio pipeline eliminates the overhead of traditional speech processing stacks.
GPT-4o's multilingual training enables voice agents that converse fluently in over 50 languages with natural pronunciation and cultural context awareness.
OpenAI's built-in content moderation and safety filters ensure voice agents stay on-topic, avoid harmful content, and follow your business guidelines.
Model Quality
Response Latency
Audio Processing
Languages
A persistent WebSocket connection is established between your telephony provider and OpenAI's Realtime API, enabling bidirectional audio streaming.
Caller audio is streamed in real-time to GPT-4o, which processes speech, understands intent, and maintains full conversation context across turns.
When the agent needs to take action, it triggers function calls to your APIs -- checking availability, creating records, or fetching data -- without breaking conversation flow.
GPT-4o generates natural speech responses with appropriate pacing, emphasis, and tone, streamed back to the caller with minimal latency.
"GPT-4o's reasoning is unmatched. Our voice agent handles complex insurance queries that required senior staff before. First-call resolution went from 60% to 88%."
88% First-Call Resolution
InsurTech
Operations Director
"The function calling capability is incredible. Our agent checks inventory, processes returns, and updates orders all during a single conversation. Customers love it."
3x Faster Processing
D2C Brand
CX Manager
Resources to help you evaluate and implement
AI-powered phone calls from ₹6/min - 60% cheaper than alternatives
Build voice agents with GPT-4o reasoning, native audio, and function calling