OpenAI: GPT-6 Astra

GPT-6 Astra is OpenAI's flagship model for demanding end-to-end work. It is suited for advanced analysis, software engineering, deep research, scientific work, and document creation, with particular strengths in long-horizon agentic tasks that involve computer and browser use.

The GPT-6 Astra documentation on OpenRouter includes the GPT-6 Migration Guide cookbook. The quickstart covers API keys and your first request, and the API reference lists every parameter.

GPT-6 Astra costs $10.00/M input tokens and $50.00/M output tokens, with separate rates for Cache Read at $1.00/M tokens, Cache Write at $12.50/M tokens, and Web Search at $10.00/1K calls.

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

Yes. GPT-6 Astra 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 Astra 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 Astra accepts files such as PDFs, images, and text as input and returns text.

GPT-6 Astra is served by 3 providers on OpenRouter: OpenAI, Azure, and Amazon Bedrock. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

GPT-6 Astra was released on September 4, 2026.