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openai/gpt-6-astra-pro
GPT-6 Astra Pro
GPT-6 Astra Pro is the same underlying model as [GPT-6 Astra](https://openrouter.ai/openai/gpt-6-astra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
9/4/2026
1,050,000 tokens
Input: ¥1,717.723/M
Output: ¥8,588.615/M
Specifications
Modalities
Input
file
image
text
Output
text
Supported Parameters
include_reasoning
max_completion_tokens
max_tokens
reasoning
reasoning_effort
response_format
seed
structured_outputs
tool_choice
tools
Max Output Tokens
128,000Reasoning Configuration
- Default
- Thinking on (effort: medium)
- Selectable effort levels
- maxxhighhighmediumlow
- Turning thinking off
- Not possible (always thinks)
Code Examples
curl https://api.fastmetal.ai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "gpt-6-astra-pro",
"messages": [{"role": "user", "content": "Hello!"}]
}'Frequently asked questions
- How much does the GPT-6 Astra Pro API cost?
- On FastMetal, GPT-6 Astra Pro is billed per token in yen: ¥1,717.72 per 1M input tokens and ¥8,588.62 per 1M output tokens, before tax. Usage is drawn from a prepaid balance; there is no subscription or monthly fee.
- Can I call GPT-6 Astra Pro with the OpenAI SDK?
- Yes. Point base_url at https://api.fastmetal.ai/v1 and pass "gpt-6-astra-pro" as the model; existing OpenAI-style code works unchanged, including streaming, tool calls and structured output.
- What is the context window of GPT-6 Astra Pro?
- 1,050,000 tokens, shared between the prompt and the response.
- What do I need to try GPT-6 Astra Pro?
- Create an account and add credit; the model is then available both in the browser chat and over the API. There is no contract or minimum spend.
Try GPT-6 Astra Pro right now
GPT-6 Astra Pro is available on FastMetal through one API key. Start in the browser, or call it from the OpenAI SDK.