OpenAI: GPT-6 Luna (batch)

GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol. It is suited for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic tasks, and at higher reasoning effort it can take on complex software engineering and computer-use tasks that previously called for a Sol-tier model.

The GPT-6 Luna (batch) documentation on OpenRouter includes the GPT-6 Migration Guide cookbook, the Reranking in RAG: How to Fix Bad Retrieval with a Reranker blog post, the How to Benchmark LLMs blog post, the How to Stop an AI Agent Stuck in an Infinite Loop blog post, the MCP vs CLI vs Skills: What Each Costs in Context blog post, the LLM API Rate Limits: How to Fix OpenAI and Claude 429 Errors blog post, the How to Get Structured Output from Any LLM: JSON Schema, Tool Calls, or a Decision Model blog post, the How to Build a Voice AI Agent blog post, the Build an AI Code Reviewer with OpenRouter blog post, and the How to Extract Tables from a PDF with an LLM blog post. The quickstart covers API keys and your first request, and the API reference lists every parameter.

GPT-6 Luna (batch) costs $0.05/M input tokens and $0.25/M output tokens, with separate rates for Cache Read at $0.005/M tokens, Cache Write at $0.0625/M tokens, and Web Search at $10.00/1K calls.

GPT-6 Luna (batch) has a 1,050,000 token context window. It supports up to 128,000 completion tokens.

Yes. GPT-6 Luna (batch) accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

Yes. OpenAI caches prompts of 1024 tokens or more automatically, and GPT-6 Luna (batch) bills a cache write on each cached prompt whether or not the cached prefix is read again. To turn caching off for a request, set prompt_cache_options.mode to "explicit" at the request root and do not mark any content block with prompt_cache_breakpoint. Explicit mode disables OpenAI-managed breakpoints, so a request with none of your own has no cacheable prefix and is billed at the plain input rate. See the prompt caching guide.

GPT-6 Luna (batch) accepts files such as PDFs, images, and text as input and returns text.

GPT-6 Luna (batch) is served by 1 provider on OpenRouter: OpenAI.

GPT-6.1 Terra Pro, GPT-6.1 Terra, GPT-6 Luna Decisions and 58 more are other text models from OpenAI.

GPT-6 Luna (batch) was released on September 22, 2026.