OpenAI API
GPT-5.6 Luna API Pricing 2026 — Cost per 1 Million Tokens
Current GPT-5.6 Luna API pricing from OpenAI per 1 million tokens, including input, output and cached-token rates when available.
| Model | Rate | Price / 1M tokens |
|---|---|---|
| GPT-5.6 Luna Cost-optimized GPT-5.6 tier for high-volume workloads. 1.05M context · 128K max output · text/image input · reasoning and tools. Requests above 272K input tokens cost 2x input and 1.5x output for the full request; cache writes cost 1.25x uncached input. | Input | $0.2 |
| GPT-5.6 Luna | Cached input | $0.02 |
| GPT-5.6 Luna | Output | $1.2 |
How API token cost is calculated
Multiply the number of tokens by the provider rate, then divide by 1,000,000.
cost = tokens × price per 1M ÷ 1,000,000
Example: 250,000 input tokens at $2 / 1M = $0.50.