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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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About GPT 5.6 Luna

GPT 5.6 Luna became available on AI Gateway on July 9, 2026 as the fast, low-cost model of the GPT-5.6 family, alongside GPT-5.6 Sol and GPT-5.6 Terra. All three GPT-5.6 models handle agentic work across coding, biology, and cybersecurity better than the previous generation, and all three use fewer tokens to reach an answer.

OpenAI built GPT 5.6 Luna for cost-sensitive, high-volume workloads, and it maps to the nano tier of earlier GPT-5 families. The point of the tier is unit economics: features that touch every request, every session, or every document stay viable when the per-request cost stays low.

GPT 5.6 Luna accepts text and image input and returns text, with a context window of 1.1M tokens and up to 272K tokens of output per request. Reasoning tokens, streaming, function calling, and structured outputs are supported, and the Responses API adds web search, file search, code interpreter, computer use, and MCP (Model Context Protocol) tools. The large context window means a low-cost model can still read a long document in one pass.

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, from TypeScript or Python. 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. AI Gateway mirrors provider pricing with no markup and adds no platform fee on inference, including for Bring Your Own Key requests.