OpenAIText Generation/v1/ai/chatReasoning

GPT-6 Astra API

Access GPT-6 Astra through one API key. OpenAI's GPT-6 flagship for analysis, engineering and research.

OpenAI's GPT-6 flagship for demanding end-to-end work: advanced analysis, software engineering, deep research, scientific work and document creation, with a 1M token context window and 128K output tokens.

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Takes 30 seconds.

GPT-6 Astra API pricing

Pay per request from your YepAPI balance — no subscription, no monthly minimum. Prices updated September 27, 2026.

Token type	Price
Input	$14.77 / 1M tokens
Output (incl. reasoning)	$73.85 / 1M tokens
Context window	1.1M tokens

What it costs	Per job	Per 1,000
Chat reply1K input + 500 output tokens	$0.052	$51.70
RAG answer8K input + 800 output tokens	$0.177	$177.24
Agent step with tools30K input + 2K output tokens	$0.591	$590.80
Long document summary100K input + 2K output tokens	$1.62	$1,624.70

4,900+

Developers

2.3M+

API calls served

184

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see GPT-6 Astra respond in real time.

POST/v1/ai/chatopenai/gpt-6-astra

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

GPT-6 Astra specs

Provider	OpenAI
Model ID	openai/gpt-6-astra
Endpoint	/v1/ai/chat
Type	Text Generation
Context window	1.05M tokens
Max output	128K tokens
Reasoning	Yes
OpenAI-compatible	Yes — /v1/ai/chat/completions

How to get a GPT-6 Astra API key

1
Create an account
Sign up at yepapi.com with Google or email. It takes about 30 seconds.
2
Create an API key
Open the dashboard, go to API Keys and create a key. Copy it — it starts with yep_sk_.
3
Call GPT-6 Astra
Send a request to /v1/ai/chat with the x-api-key header and model "openai/gpt-6-astra".
4
Pay as you go
Usage is billed per request from your balance. Top up any amount; there is no subscription.

Strengths

✓

GPT-6 flagship

GPT-6 Astra sits at the top of OpenAI's GPT-6 series, above the cost-efficient Sol and fast Luna tiers, and succeeds GPT-5.5 as the model for the hardest reasoning and engineering tasks.

✓

Long-horizon agentic work

Built for multi-step, long-running work — deep research, large refactors, scientific analysis — where the model plans, calls tools, and iterates over many turns without losing the thread.

✓

1M token context, 128K output

Handles up to 1,050,000 input tokens and returns up to 128,000 output tokens per call, so whole codebases and document sets go in and complete deliverables come out in one request.

✓

Tools, structured output, reasoning control

Supports function calling, JSON schema structured outputs, seeds, and a tunable reasoning effort so you can trade latency for depth per request.

Quick start

Copy this snippet and start making calls with GPT-6 Astra.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "openai/gpt-6-astra",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

GPT-6 Astra vs similar models

Every model below runs on the same API key — switch by changing the model ID.

Model	Provider	Price	Context
GPT-6 Astra	OpenAI	$14.77 in / $73.85 out per 1M	1.1M
GPT-6 Luna	OpenAI	$0.15 in / $0.74 out per 1M	1.1M
GPT-6 Luna Pro	OpenAI	$0.15 in / $0.74 out per 1M	1.1M
GPT-4o Mini	OpenAI	$0.22 in / $0.89 out per 1M	128K
GPT-OSS 120B	OpenAI	$0.22 in / $0.89 out per 1M	131K
GPT-5.6 Luna	OpenAI	$0.30 in / $1.77 out per 1M	1.1M
Nemotron 3 Super	NVIDIA	$0 in / $0 out per 1M	262K
Qwen3.7 Flash	Qwen	$0.04 in / $0.19 out per 1M	1M

Why use GPT-6 Astra through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

GPT-6 Astra API — pricing, context window & access

GPT-6 Astra is the flagship of OpenAI's GPT-6 series, positioned above GPT-6 Sol and GPT-6 Luna and succeeding GPT-5.5. It is built for demanding end-to-end work: advanced analysis, software engineering, deep research, scientific work and document creation, with a 1,050,000-token context window and up to 128,000 output tokens per response.

Through YepAPI you call GPT-6 Astra on an OpenAI-compatible endpoint with a single key — the same key that reaches the GPT-5.5 family, Claude, Gemini, Grok, and the SEO, SERP and scraping APIs.

What is GPT-6 Astra?

GPT-6 Astra is OpenAI's top-tier GPT-6 model, tuned for long-horizon agentic work rather than quick chat. It plans across many steps, uses tools reliably, and keeps a coherent working memory across a 1M-token context, which makes it the model for jobs like end-to-end software changes, multi-source research reports, and scientific or quantitative analysis. Its 128K output ceiling means it can return an entire implementation or report in one call. A companion GPT-6 Astra Pro variant runs the same model in a higher-effort reasoning mode.

Build with GPT-6 Astra via YepAPI

YepAPI serves GPT-6 Astra on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to gpt-6-astra (or the full openai/gpt-6-astra). Function calling, structured outputs and the reasoning effort parameter pass straight through. Routing routine work to GPT-5.4 Mini or Gemini Flash and reserving Astra for the hard steps is a one-string change per request.

GPT-6 Astra API pricing — $14.77 / 1M input, $73.85 / 1M output

GPT-6 Astra costs $14.77 per 1M input tokens and $73.85 per 1M output tokens through YepAPI, pay per token with no minimums. It is a frontier flagship, so budget for it deliberately: the 1M-token window and 128K output ceiling mean a single large agentic run can consume a meaningful amount of credit. For lighter tasks GPT-6 Sol and Luna offer the same series at a fraction of the price.

GPT-6 Astra for engineering, research and analysis

Astra is the right pick when the task is long and the cost of a wrong answer is high: multi-file refactors that must compile, research syntheses across dozens of papers, financial or scientific analysis with intermediate reasoning, and long documents drafted from large source material. Its tool use and structured outputs make it a strong engine for autonomous agents, and the reasoning effort control lets you dial depth up only where it matters.

Start generating in 30 seconds

Pay per call, no subscriptions.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

GPT-6 Astra costs $14.77 per 1M input tokens and $73.85 per 1M output tokens through YepAPI, billed per request with no monthly fee. For example, a chat reply (1K input + 500 output tokens) costs about $0.052.

Sign up at yepapi.com (Google or email, about 30 seconds), open the dashboard and create an API key. The same key works for GPT-6 Astra and every other model — no separate OpenAI account or waitlist.

Use "openai/gpt-6-astra" as the model on /v1/ai/chat. The short alias "gpt-6-astra" also works.

Yes. Point the OpenAI SDK at https://api.yepapi.com/v1/ai with your YepAPI key and set model to "openai/gpt-6-astra". Streaming works the same way, so existing OpenAI code only needs the base URL and key changed.

GPT-6 Astra supports a 1.1M token context window with up to 128K output tokens per request.