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.
import { streamText } from 'ai'
const result = streamText({ model: 'openai/gpt-5.6-luna', prompt: 'Why is the sky blue?'})Playground
Try out GPT 5.6 Luna by OpenAI. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days.
GPT 5.6 Luna
GPT 5.6 Luna
Providers
Route requests across multiple providers. Copy a provider slug to set your preference. Visit the docs for more info. Using a provider means you agree to their terms, listed under Legal.
| Provider |
|---|
| 1.1M | 128K | 1.9s | 145tps | $1/M$0.20/M +4 more | $6/M$1.20/M +4 more | Read:$0.1/M$0.02/M+2 more Write:$1.25/M$0.25/M+2 more | $10/K + input costs | +4 | 07/09/2026 | |||||
| 1.1M | 128K | 1.6s | 133tps | $1/M+1 more | $6/M+1 more | Read: $0.1/M+1 more Write: $1.25/M+1 more | $14/K + input costs | +3 | 07/09/2026 | |||||
| 272K | 272K | 3.0s | 99tps | $1.10/M$0.22/M +1 more | $6.60/M$1.32/M +1 more | Read: $0.11/M$0.02/M+1 more Write: $1.38/M$0.28/M+1 more | $10/K + input costs | +3 | 07/09/2026 |
P50 throughput on live AI Gateway traffic, in tokens per second (TPS). Visit the docs for more info.
P50 time to first token (TTFT) on live AI Gateway traffic, in milliseconds. View the docs for more info.
Direct request success rate on AI Gateway and per-provider. Visit the docs for more info.
More models by OpenAI
| Model |
|---|
| 1.1M | 2.7s | 95tps | $5/M+1 more | $30/M+1 more | Read: $0.5/M+1 more Write: $6.25/M+1 more | $10/K + input costs | +4 |   | 07/09/2026 | ||||
| 400K | 0.5s | 138tps | $0.20/M | $1.25/M | Read:$0.02/M Write:— | $10/K + input costs | +4 | | 03/17/2026 | ||||
| 400K | 1.1s | 178tps | $0.75/M | $4.50/M | Read:$0.07/M Write:— | $10/K + input costs | +4 | | 03/17/2026 | ||||
| 400K | 5.4s | 147tps | $0.05/M | $0.40/M | Read:$0.01/M Write:— | $14/K + input costs | +3 | | 08/07/2025 | ||||
| 400K | 2.8s | 163tps | $0.25/M | $2/M | Read:$0.03/M Write:— | $14/K + input costs | +3 | | 08/07/2025 | ||||
| 131K | 0.2s | 481tps | $0.35/M | $0.75/M | Read:$0.25/M Write:— | — |   +5 | 08/05/2025 |
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.
What To Consider When Choosing a Provider
- Configuration: GPT 5.6 Luna corresponds to the nano tier of earlier GPT-5 families and targets cost-sensitive, high-volume workloads. Upstream list prices came down after launch, and AI Gateway passes the provider rate through with no markup.
- Configuration: The tradeoff is capability headroom. Classification, extraction, routing, and short generation suit GPT 5.6 Luna; multi-step agentic runs and hard research questions belong on GPT-5.6 Terra or GPT-5.6 Sol. Test that boundary with your own prompts, because a lower rate only pays off while output quality holds.
- Zero Data Retention: AI Gateway supports Zero Data Retention for this model via direct gateway requests (BYOK is not included). To configure this, check the documentation.
- Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.
When to Use GPT 5.6 Luna
Best for
- High-Volume Classification: Labeling, routing, and moderation pipelines that run on every request
- Structured Extraction: Pulling fields from documents, tickets, and logs at scale
- Fast Interactive Responses: Autocomplete, summaries, and suggestions in latency-sensitive surfaces
- Agent Support Steps: Cheap intermediate turns in a pipeline that escalates when a step gets hard
- Cost-Bound Product Features: Surfaces where per-request price decides whether the feature ships
Consider alternatives when
- Balanced Everyday Work: GPT-5.6 Terra weighs intelligence against cost for general production traffic
- Hardest Agentic Tasks: GPT-5.6 Sol is the flagship and the most capable model in the family
- Autonomous Coding Agents: GPT-5.x codex variants target sandboxed software engineering directly
- Live Voice Interfaces: The gpt-realtime family handles speech-to-speech conversation natively
Conclusion
GPT 5.6 Luna is where high-volume GPT-5.6 traffic belongs: the lowest price in the family, the same context window as its siblings, and the generation's agentic gains. Run the repetitive work here and escalate to GPT-5.6 Terra or GPT-5.6 Sol when a request needs more depth.