# GPT-5.6 Luna

GPT-5.6 Luna is a language model from OpenAI with a 1M-token context window. Provider list price is $0.20 per million input tokens and $1.20 per million output; on Allocate you pay $0.21 and $1.28. It is a closed model served over API; the weights are not published.

## Pricing

| | Provider list | On Allocate |
| --- | --- | --- |
| Input, per M tokens | $0.20 | $0.21 |
| Output, per M tokens | $1.20 | $1.28 |
| Cached input, per M tokens | $0.02 | $0.021 |

Prices checked 2026-07-21.

## Facts

| Field | Value |
| --- | --- |
| Lab | OpenAI |
| Modality | Language |
| Context window | 1M tokens |
| License | Proprietary API |
| Open weights | No |
| Fine-tunable | No |
| Catalog id | openai/gpt-5.6-luna |

## What a real workload costs

Take 1,000,000 requests a month at 1,200 input and 350 output tokens each: 1,200M input and 350M output tokens. At list prices that is 1,200 × $0.20 + 350 × $1.20 = $660 a month. Billed on Allocate it is $706.20.

## Common questions

### How much does GPT-5.6 Luna cost per million tokens?

Provider list price is $0.20 per million input tokens and $1.20 per million output tokens. On Allocate you pay $0.21 in and $1.28 out.

### What context window does GPT-5.6 Luna have?

1,000,000 tokens (1M). At roughly 0.75 words per token, that is about 750k words of English text per request.

### What does cached input cost on GPT-5.6 Luna?

$0.02 per million tokens at list ($0.021 billed). Repeated prompt prefixes, such as a stable system prompt or tool definitions, bill at this rate instead of the full input price.

### Can I fine-tune GPT-5.6 Luna?

No. GPT-5.6 Luna is a closed model served over API; the weights are not published. If you want a model you can train and own, start from an open-weights base in the catalog and fine-tune that.

### How do I call GPT-5.6 Luna on Allocate?

Send openai/gpt-5.6-luna in the model field of the OpenAI-compatible endpoint at api.allocate.network/v1, or point a route name (like prod/support-agent) at it so you can swap the model later without a deploy.

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[HTML page](https://allocate.network/models/openai-gpt-5-6-luna) · [Machine-readable catalog](https://allocate.network/catalog.json)