GPT-5.6 Luna
Reasoning model by OpenAI.
OpenAI advanced reasoning model. Utilizes structured deliberation tokens for multi-step reasoning, mathematical problem solving, and complex logic.
Context window
Maximum input context length.
1.05M
Max output
Maximum completion tokens per request.
128K
Maker
OpenAI
Specifications
Context window, ranked against other reasoning models
Proportional scale: 0 to 1.05M tokens. Not ranked, no published context window: gpt-5.2-pro-2025-12-11, gpt-5.4-pro, grok-4-1-fast-non-reasoning, grok-4-1-fast-reasoning, gpt-5.2-pro.
1.1M
tokens128K
tokensreasoning
Pricing
Rates are read live
Pricing for gpt-5.6-luna is fetched from the live catalogue on load, so it is never served from a cache that could outlive a repricing.
Availability
Not enough data yet
We have not collected enough health probes for this model to publish an uptime or latency figure. A percentage from a handful of samples is fabricated precision, so none is shown until the sample count supports one.
How GPT-5.6 Luna is billed
Billed at the provider's list price, with no per-token markup.
- Exact list price
- Tokens settle at the published rate of the model that served your call.
- Cache discounts passed through
- Provider prompt-caching discounts reach your balance with no added fee.
- Cost on every response
- Each response carries the
x-nr-request-costheader, so you can reconcile spend per request.
More from OpenAI
Start building with gpt-5.6-luna
One API key, three steps. Choose your tool to begin.
Get a key
Create API keySet your API key
export NROUTER_API_KEY="<YOUR_API_KEY>"Configure Claude Code
Choose a tool, then copy its setup from the panel.
FAQs
What is GPT-5.6 Luna?
OpenAI advanced reasoning model. Utilizes structured deliberation tokens for multi-step reasoning, mathematical problem solving, and complex logic.
How much does GPT-5.6 Luna cost?
GPT-5.6 Luna is billed at the provider's list price on nRouter with no per-token markup — tokens settle at the exact upstream rate. Input and output rates are read live, so see the pricing section above for the current figures.
What is the context length of GPT-5.6 Luna?
GPT-5.6 Luna supports a 1,050,000-token context window. It can generate up to 128,000 output tokens per request.
Does GPT-5.6 Luna support tool calling and structured outputs?
Yes. GPT-5.6 Luna supports tool calling (function calling), so it can invoke external tools and APIs during a conversation.
What inputs and outputs does GPT-5.6 Luna support?
GPT-5.6 Luna takes text and images as input and returns text as output.
How do I use GPT-5.6 Luna via nRouter?
Use any OpenAI-compatible client: point it at https://api.nrouter.ai/v1 with your nRouter API key and set the model to "openai/gpt-5.6-luna". The quick-start panel above has a copy-paste curl command for this model.
When was GPT-5.6 Luna released?
GPT-5.6 Luna was released on August 30, 2026.
Where is the GPT-5.6 Luna documentation?
Start at nrouter.ai/docs. The quick-start guide (nrouter.ai/docs/getting-started/quick-start) covers API keys and your first request, and the API reference (nrouter.ai/docs/api-reference) lists every parameter.
What other text models does OpenAI have?
Other OpenAI text models on nRouter include GPT-OSS 120B 1 (nrouter.ai/models/gpt-oss-120b-1), GPT-6.1 Sol (nrouter.ai/models/gpt-6.1-sol), GPT-5.2 Pro (nrouter.ai/models/gpt-5.2-pro-2025-12-11), GPT Audio 1.5 (nrouter.ai/models/gpt-audio-1.5).