GPT-6 Astra on Run BiOS
gpt-6-astra
Top up $20 and we add 50%. That gives you about 1.0M input tokens extra on GPT-6 Astra, on us.
Create an accountPricing
USD per 1M tokens| Input | $10.00 |
| Output | $50.00 |
| Cached input | $1.0090% below fresh input |
| Cache write (5m) | $12.50 |
Billed per token with no minimum and no monthly fee. Price your workload
Capabilities and limits
- Context window
- 266K tokens
- Max output
- 125K tokens
- Modality
- multimodal
- Tool calling
- Supported
- Vision
- Supported
- Reasoning
- Always on
- Reasoning effort
- low, medium, high, xhigh, max (default: medium)
- Prompt caching
- Supported (automatic)
- Cache minimum
- 1K tokens
Measured performance
7d- Time to first token (p50)
- 3.0 s
- Time to first token (p95)
- 12 s
- Throughput (avg)
- 65.7 tok/s
- Throughput (p50)
- 100.0 tok/s
Measured on real Run BiOS traffic over the trailing 7d. Your figures will vary with prompt shape and region.
curl https://api.runbios.ai/v1/chat/completions \
-H "Authorization: Bearer $BIOS_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-6-astra",
"messages": [{ "role": "user", "content": "Hello" }]
}'Existing OpenAI SDK code works by changing the base URL and the key. API overview
Model card
Curated by Run BiOS · benchmark figures, where present, are the card’s own, not our measurements
GPT-6 Astra is OpenAI's most capable model, built for the hardest end-to-end work. OpenAI recommends it for complex reasoning, coding, research, and document creation.
It is the most capable model in the GPT-6 family, alongside GPT-6 Sol and GPT-6 Luna. GPT-6 Astra always reasons: it does not support turning reasoning off.
Model details
| Property | Value |
|---|---|
| Developer | OpenAI |
| Model ID | gpt-6-astra |
| OpenAI default snapshot | gpt-6-astra |
| Input | Text, image |
| Output | Text |
| Context window | 272,000 tokens on Run BiOS (OpenAI's full window is 1,050,000 tokens) |
| Max output tokens | 128,000 |
| Knowledge cutoff | Apr 30, 2026 |
| Reasoning | Yes |
Details above are from OpenAI's official model page; context window and input types are as served on Run BiOS.
On Run BiOS
- Always reasons. Reasoning levels
low,medium,high,xhigh,max; the default ismedium. This model cannot turn reasoning off: a request for no reasoning runs at the lowest available level. - Reasoning summaries. When reasoning is on, OpenAI may return a summary of the model's reasoning: in
reasoning_contenton the OpenAI API, and in thinking blocks on the Anthropic Messages API whenthinking.displayissummarized. OpenAI does not return a summary for every request. - Tool calling. Function tools with
tool_choiceauto, required, a named function or none, including parallel tool calls, and together with reasoning. - Structured outputs.
response_formatwithjson_schemaorjson_object. - Image input. Text and image input, text output.
- Sampling parameters.
temperature,top_p, penalties,stopandseedare not applied to this model on Run BiOS, because it always reasons; the request is still served. - Prompt caching. Automatic for repeated prompt prefixes of at least 1,024 tokens. Cache reads bill at 0.1× the input rate and cache writes at 1.25×, as OpenAI charges.
- Two APIs. Works with the OpenAI Chat Completions API (
/v1/chat/completions) and the Anthropic Messages API (/v1/messages).