GPT-5.6 Luna

Q: What is the API model name for GPT-5.6 Luna?

Use gpt-5.6-luna in API calls to OpenAI. The context window is 1.05M tokens, and a response can run to 128,000 output tokens.

GPT-5.6 Luna API cost is $0.20 per million input tokens and $1.20 per million output tokens.

Provider: OpenAI
API model name: gpt-5.6-luna
Status: Previous generation
Input, $ per 1M tokens: $0.20
Cached input, $ per 1M tokens: $0.02
Output, $ per 1M tokens: $1.20
Sample request (10K in, 2K out), $: $0.0044
Context window, tokens: 1.05M
Price checked on: October 27, 2026
Official pricing page: developers.openai.com

These are standard rates on OpenAI’s own API. Cached input is billed at $0.02 per million tokens. A request with 10,000 input tokens and 2,000 output tokens costs about $0.0044 before caching or batch discounts. The API model name is gpt-5.6-luna, and the context window is 1.05M tokens. OpenAI’s current GPT-6 Luna runs the same request for about $0.002.

Cache writes, $ per 1M tokens: $0.25
Max output, tokens: 128K
Input types: Text, image, file
Open weights: No
Long-context pricing: $0.40 input, $0.04 cached input, $0.50 cache writes, $1.80 output
Sources: Page URL Checked
OpenAI API pricing https://developers.openai.com/api/docs/pricing 2026-10-21
OpenAI GPT-5.6 Luna model page (prices) https://developers.openai.com/api/docs/models/gpt-5.6-luna 2026-09-30
OpenRouter model listing (context and output limits) https://openrouter.ai/models 2026-09-29

Page	URL	Checked
OpenAI API pricing	https://developers.openai.com/api/docs/pricing	2026-10-21
OpenAI GPT-5.6 Luna model page (prices)	https://developers.openai.com/api/docs/models/gpt-5.6-luna	2026-09-30
OpenRouter model listing (context and output limits)	https://openrouter.ai/models	2026-09-29

Questions

How much does the GPT-5.6 Luna API cost?

GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens on OpenAI’s own API. Cached input costs $0.02 per million tokens.

What is the API model name for GPT-5.6 Luna?

Use gpt-5.6-luna in API calls to OpenAI. The context window is 1.05M tokens, and a response can run to 128,000 output tokens.

What does one GPT-5.6 Luna request cost?

A request with 10,000 input tokens and 2,000 output tokens costs about $0.0044 at standard rates, before caching or batch discounts.

Does GPT-5.6 Luna cost more for long prompts?

Yes. OpenAI lists long-context rates per million tokens: $0.40 input, $0.04 cached input, $0.50 cache writes, $1.80 output.

Sources

Prices are read from each provider’s official pricing page: OpenAI, Anthropic, Google Gemini API, xAI, DeepSeek and Mistral AI. Context and output limits that a provider does not publish come from OpenRouter’s model listing. Each model’s Sources field lists the pages used and the date each was checked. How we check prices · Price change log