OpenAI's flagship reasoning model for demanding end-to-end work. It supports an approximately 1.05-million-token context, up to 128K output tokens, and five reasoning-effort levels for complex analysis, coding, planning, and professional text generation.
OpenAI
GPT-6 Astra is OpenAI's flagship model for demanding end-to-end work. It offers strong multi-step reasoning, code understanding and generation, complex analysis, planning, and professional writing for text tasks that require high accuracy, completeness, and instruction following.
The model provides a 1,050,000-token context window and up to 128,000 output tokens, helping it maintain continuity across long conversations and large amounts of text. It supports low, medium, high, xhigh, and max reasoning-effort levels so applications can balance task difficulty, response time, and cost.
| Feature | Benefit |
|---|---|
| 1,050,000-Token Context Window | Processes large text collections, extended code context, and long conversations in one task. |
| 128,000 Maximum Output Tokens | Produces substantial reports, code, and structured plans, subject to the production Azure route. |
| Five Reasoning-Effort Levels | Adjusts the trade-off among latency, cost, and answer quality for different workloads. |
| Strong Complex-Task Performance | Supports multi-step analysis, constraint checking, planning, and professional communication. |
| Streaming and Non-Streaming Output | Supports responsive chat experiences and complete text responses. |
It is suited to complex analysis, software development, technical planning, research synthesis, long-text processing, professional writing, and multi-step decision support. Lighter models may be more economical for simple classification or short rewriting tasks.
When a request contains more than 272,000 input tokens, long-context rates apply to the entire request, including all input, cached input, cache writes, and output tokens—not only the tokens above the threshold.
No. The original model's official capabilities are broader than the capabilities currently exposed by LinkModel. This listing supports text-only chat and must not show image, file, audio, or video input controls.
No. Function calling, web search, file search, computer use, code execution, MCP, and other tools are outside the scope of this listing.
Start with low or medium for general text tasks. Evaluate high, xhigh, or max for complex code, rigorous analysis, and multi-step planning. Higher reasoning effort may increase latency and output-token consumption, so applications should test quality and cost together.
Tiered by input prompt tokens (incl. cache): once over the threshold, the whole request is billed at the higher tier.
| Token Type | Short context ≤272K | Long context >272K |
|---|---|---|
| Input | $7.5$10-25% | $15$20-25% |
| Output | $37.5$50-25% | $56.25$75-25% |
| Cached input | $0.75$1-25% | $1.5$2-25% |
| Cache write | $9.375$12.5-25% | $18.75$25-25% |