Realtime prompting guide
type: NewsArticle
description: OpenAI released `gpt-realtime-2`, a reasoning voice model for low-latency speech-to-speech applications that can think before speaking, follow instructions more reliably, and use a 128k-token context window. The company issued a prompting guide advising developers to design prompts with clear intent, start with minimal instructions, and tune reasoning effort from low to high based on task complexity and latency tolerance.
date published: 2026-05-05 00:00:00+00:00
date modified: 2026-06-03 03:06:08.804755+00:00
language: en
is accessible for free: true
article body: `gpt-realtime-2` is our state-of-the-art reasoning voice model for low-latency speech-to-speech applications. It can think before it speaks, follow instructions more reliably, use a larger context window, and call tools with greater precision than earlier realtime models. To take advantage of these gains, design prompts with more intent. Define the assistant’s responsibilities, decision points, tool-calling behavior, and guardrails clearly: what it should do, when it should do it, and what it should avoid. Start simple. Do not over-prompt upfront. Begin with a minimal prompt, run evaluations, then add instructions only for behaviors that fail in testing. ## Choose a model | Model | Use when | Prompting focus | |---|---|---| `gpt-realtime-2` | You need the strongest realtime reasoning, tool use, and instruction following. Tune reasoning effort, preambles, tool policies, exact entity capture, and long-session state. `gpt-realtime-1.5` Follow the core realtime prompt structure and test for latency-sensitive behavior. ## Realtime 2.0 Prompting Guide Use `gpt-realtime-2` when the voice agent needs stronger reasoning, tool selection, exact entity handling, or long-session state. Start with `reasoning.effort: “low”` , test default preamble behavior, and define clear confirmation boundaries before write actions. ## What changed in Realtime 2 Prompt Realtime 2 as a reasoning voice agent, not as a basic voice bot. | Change | What it means for prompts | |---|---| | Reasoning | Allow the model to reason internally for complex tasks before speaking or calling tools. Use preambles to avoid awkward silence or unnecessary filler. | | Prompt precision matters more | Replace broad guidance like “be helpful” with clear trigger, action, and exception rules: when to act, what to do, and when not to do it. | | Instruction conflicts are more costly | Remove overlapping `always` , `never` , `only` , and `must` rules unless they are truly required. Define priority when rules compete. | | To…
publisher: Web Pulse
keywords: large-language-models, artificial-intelligence, ai-products, ai-tools, ai-agents
mentions: gpt-realtime-2
mentions: gpt-realtime-1.5
citation: CreativeWork