gpt-realtime-1.5 by OpenAI logo

gpt-realtime-1.5 by OpenAI

Tighter instruction adherence in speech agents

2026-02-26

Product Introduction

  1. Definition: GPT-realtime-1.5 is a multimodal, low-latency large language model (LLM) within OpenAI’s Realtime API, designed for synchronous speech-to-speech interactions. It processes audio, text, and image inputs to generate real-time audio and text outputs.
  2. Core Value Proposition: It enables developers to build responsive voice agents and real-time transcription systems by drastically reducing conversational latency and enhancing reliability in instruction following, tool execution, and multilingual accuracy.

Main Features

  1. Enhanced Instruction Following:
    Utilizes chain-of-thought reasoning and structured output parsers to interpret complex user commands precisely. Operates via WebRTC/WebSocket protocols to maintain sub-second response times, critical for natural voice conversations.
  2. Stateful Tool Calling:
    Integrates with OpenAI’s Tools framework (e.g., Code Interpreter, Web Search, File Retrieval) via persistent Realtime API sessions. Maintains conversation context across interactions, allowing sequential tool execution without redundant context re-injection.
  3. Multilingual Speech Accuracy:
    Leverages acoustic and language models fine-tuned on diverse phonetics and dialects. Supports real-time translation and accent adaptation using dynamic beamforming and noise suppression in audio streams.

Problems Solved

  1. Pain Point: Eliminates disruptive latency (>2s) in voice AI interactions, which breaks conversational flow and degrades user experience.
  2. Target Audience:
    • Conversational AI Developers building voice assistants (e.g., contact center bots, IVR systems).
    • Global CX Product Managers requiring real-time multilingual support.
    • Telephony Integrators using SIP/WebRTC infrastructure.
  3. Use Cases:
    • Real-time customer support agents handling spoken queries.
    • Live multilingual meeting transcription/translation.
    • Interactive voice-controlled tools (e.g., code debugging via speech).

Unique Advantages

  1. Differentiation:
    Outperforms generic speech APIs (e.g., Google Speech-to-Text) with unified multimodal processing. Unlike batch-based LLMs, it streams responses incrementally via WebSocket mode, enabling true real-time interactivity.
  2. Key Innovation:
    Realtime API’s session architecture combines WebRTC for browser-based audio streaming and WebSocket for server-side tool orchestration. Adaptive token streaming prioritizes low-latency audio chunks over text completeness.

Frequently Asked Questions (FAQ)

  1. How does gpt-realtime-1.5 reduce voice agent latency?
    It uses WebRTC for direct browser audio streaming and incremental response generation via token streaming, achieving end-to-end latency under 500ms.
  2. Can gpt-realtime-1.5 handle multilingual conversations?
    Yes, its acoustic model supports 40+ languages with dialect adaptation, and real-time translation during speech-to-speech interactions.
  3. What tools integrate with the Realtime API?
    Native support for Code Interpreter, Web Search, File Retrieval, and custom tools via OpenAI’s MCP (Modular Control Protocol) Skills framework.
  4. Is coding required to deploy voice agents?
    OpenAI’s Agents SDK provides prebuilt components for browser-based deployment, but server-side tooling requires WebSocket API integration.
  5. How does billing work for real-time audio processing?
    Costs are based on audio input seconds and output tokens, with optimizations like Flex Processing for cost-sensitive applications.

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