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GPT 5.6 Luna

GPT 5.6 Luna is the fast, low-cost model of the GPT-5.6 family, holding strong capability at the lowest price in the series while sharing the family's agentic gains in coding, biology, and cybersecurity and a context window of 1.1M tokens. Your use is subject to OpenAI's Terms & Privacy Policies.

ReasoningFile InputTool UseVision (Image)Implicit CachingWeb SearchWebsockets
Use with AI GatewayView docs
import { streamText } from 'ai'


const result = streamText({
  model: 'openai/gpt-5.6-luna',
  prompt: 'Why is the sky blue?'
})
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Frequently Asked Questions

  • What is GPT 5.6 Luna built for?

    Cost-sensitive, high-volume workloads. OpenAI built GPT 5.6 Luna as the fast, affordable tier of the GPT-5.6 family, for pipelines where per-request price decides feasibility.

  • How does GPT 5.6 Luna compare with GPT-5.6 Terra and GPT-5.6 Sol?

    GPT 5.6 Luna carries the lowest price in the family and the least capability headroom. GPT-5.6 Terra balances intelligence against cost for everyday work, and GPT-5.6 Sol is the flagship for the hardest tasks.

  • What context window and output limit does GPT 5.6 Luna support?

    1.1M tokens, with up to 272K tokens of output per request, matching the rest of the GPT-5.6 family. A low-cost tier with that much context can read long documents in one pass.

  • What inputs does GPT 5.6 Luna accept?

    Text and images, with text output. Audio and video input are not supported, so route voice work to the gpt-realtime family instead.

  • Which APIs can I use to call GPT 5.6 Luna?

    Set the model to openai/gpt-5.6-luna in the AI SDK, the Chat Completions API, the Responses API, or another supported API format. AI Gateway accepts each format and routes the request.

  • Does GPT 5.6 Luna support tool calling and structured outputs?

    Yes. Function calling, structured outputs, and streaming all work, and the Responses API adds web search, file search, code interpreter, computer use, and MCP tools.

  • What does GPT 5.6 Luna cost?

    List pricing is $0.2 per million input tokens and $1.2 per million output tokens, with cached input at $0.02. Short-context and long-context requests are priced separately, and AI Gateway mirrors provider pricing with no markup.

  • Does GPT 5.6 Luna support zero data retention through AI Gateway?

    Yes, Zero Data Retention is available for this model. Zero Data Retention is offered on a per-provider basis. See https://vercel.com/docs/ai-gateway/capabilities/zdr for details.

  • What are typical latency characteristics?

    This page shows live throughput and time-to-first-token metrics measured across real AI Gateway traffic.