OpenAI: GPT 6 Astra Pro
GPT 6 Astra Pro is a reasoning model from OpenAI released on Sep 4, 2026. It reads text, images and files and writes text, with a 1.05M token context window and up to 128K tokens per reply.
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It costs $10 per million input tokens and $50 per million output tokens. Cached input bills at $1, 90% less than fresh input.
It supports tool calling, structured JSON output and prompt caching.
2 providers serve it, including Kilo Gateway and NanoGPT.
- Modalities
- In / out price
- $10 / $50 per 1M
- Context
- 1.05M
- Max output
- 128K
- Released
- Sep 4, 2026
- Knowledge cutoff
- n/a
- Tool calling
- Structured output
- Reasoning
- Prompt caching
- Open weights
- Free to use
GPT 6 Astra Pro pricing
USD, as listed on Oct 15, 2026. Most bills are input heavy, so the cached input rate matters as much as the headline price.
| Input | $10 / 1M tokens | |
|---|---|---|
| Output | $50 / 1M tokens | |
| Cached input (read) | $1 / 1M tokens | 90% off input |
| Cache write | $12.50 / 1M tokens |
GPT 6 Astra Pro providers
2 providers serve it, including Kilo Gateway and NanoGPT. Each host sets its own price and limits, so the cheapest one is not always the one with the longest context.
| Provider | Input /M | Output /M | Cache read /M | Context | Max output |
|---|---|---|---|---|---|
| Kilo Gateway | $10 | $50 | $1 | 1.05M | 128K |
| NanoGPT | $10 | $50 | $1 | 1.05M | 128K |
What GPT 6 Astra Pro costs per month
Pick a workload close to yours or type your own volumes.
Supported request parameters
What you can set when you call GPT 6 Astra Pro through an OpenAI compatible API.
- Tools
tools - Structured outputs
structured_outputs - Reasoning
reasoning
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GPT 6 Astra Pro questions
How much does the GPT 6 Astra Pro API cost?
$10 per million input tokens and $50 per million output tokens, with cached input at $1. The estimator on this page turns that into a monthly bill for your own workload.
What is the context window of GPT 6 Astra Pro?
1,050,000 tokens of input, and it can write up to 128,000 tokens in one reply. As a rough guide, a million tokens is around 750,000 English words.
Which providers serve GPT 6 Astra Pro?
2 providers serve it, including Kilo Gateway and NanoGPT. Prices differ by host, so the Providers table on this page lists each one with its input and output price.
Does GPT 6 Astra Pro support tool calling?
Yes. It accepts tool definitions and can return JSON that matches a schema, which is what an agent needs to call your APIs.
Is GPT 6 Astra Pro open source?
No. OpenAI serves it through an API only, so you cannot download the weights or host it yourself.
When was GPT 6 Astra Pro released?
Sep 4, 2026.
Catalog data from models.dev (MIT licensed), refreshed daily, last on Oct 15, 2026. The summary is written from these facts.
Building on GPT 6 Astra Pro?
I test your real tasks on it and the two closest alternatives, then ship the agent on whichever wins on cost and accuracy.
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