GPT-6 Astra API, pricing, playground & code

Name: GPT-6 Astra API
Brand: OpenAI

Overview

About GPT-6 Astra

GPT-6 Astra is OpenAI's flagship as of September 2026, a reasoning model with a 1.05-million-token context window and a 128k maximum output, released September 3 with a knowledge cutoff of April 30, 2026. Through CompanyFabric it runs behind the same OpenAI-compatible key as every other model in the library, so putting Astra on a prompt, or A/B-ing it against Claude Fable 5, is a one-string change on one prepaid balance. Every model on CompanyFabric shares the same API key, billing balance, and rate-limit envelope, one integration covers the entire library.

Facts

At a glance

Availability

Live

Pricing

$10/Mtok in

Metered exactly per call

Context window

1,050k tokens

Commercial use

See license

Commercial output use permitted per OpenAI terms.

Variants

All endpoints

GPT-5.5

$5/Mtok in

OpenAI's flagship, one key away.

Chat Completions

GPT-6 Astra

$10/Mtok in

OpenAI's GPT-6 flagship, a million-token window one key away.

Chat Completions

Prompt library

Example runs

Here's our 40k-line service in one paste. Find the request path that can double-charge a card and show the exact lines.

The double-charge is reachable when retryPayment() runs before the idempotency key is persisted, charge.ts:212 and webhook.ts:88…

This exact run cost $0.14

Summarize this 300-page contract and flag the three riskiest clauses for a buyer.

The three clauses most worth your attention are the auto-renewal in §12, the uncapped indemnity in §19…

This exact run cost $0.05

Plan a database migration from Postgres to a sharded setup with zero downtime. Think it through at high effort.

Phase 1, dual-write behind a feature flag; Phase 2, backfill with a bounded reconciler…

This exact run cost $0.03

Quickstart

How to use the GPT-6 Astra API

1
Create a free CompanyFabric account, starter credits are included, no card required.
2
Copy your API key from the dashboard. One key covers every model in the library.
3
Point any OpenAI SDK at api.companyfabric.com/v1 and set model to "openai/gpt-6-astra".
4
Read the exact metered cost of the call from the response, the same number shown in the playground.

Use cases

What teams build with it

Whole-repo and whole-corpus reasoning

A million-token window holds an entire codebase, a data room, or a book of contracts in one call, no chunking, no retrieval glue, the reasoning happens over the full context.

long context1M tokenscodebase

Hard multi-step reasoning

The calls where being right matters more than being fast, architecture decisions, proofs, root-cause analysis, tuned up with a higher reasoning effort.

reasoningplanninganalysis

Frontier agent loops

Long-horizon tool chains that must not drift, with tools, vision, and streaming all passing through the OpenAI-compatible endpoint unchanged.

agentstool usefrontier

Get better output

Prompting tips

Use the full window deliberately: paste the whole source rather than a summary, Astra reasons better over primary text than over your compression of it.
Set reasoning effort to match the task, minimal for extraction and formatting, high for the calls where a wrong answer is expensive. Effort trades latency and output tokens for depth.
Watch the long-context tier: input over 272k tokens bills at the higher rate for the whole request, so a retrieval step that trims the prompt often pays for itself.

Exact, metered, prepaid

GPT-6 Astra pricing

GPT-6 Astra is metered per token at OpenAI's published rate: $10 per million input tokens and $50 per million output, with cached input at $1. Prompts above 272k input tokens move to the long-context tier ($20 input, $75 output) for the whole request.

Every call is priced before you run it in the playground and metered exactly to your prepaid balance, no subscription, no minimum. BYOK routes your own OpenAI key at 0% platform fee.

Endpoint	Type	Price
GPT-5.5	Chat	$5 / M input · $30 / M output
GPT-6 Astra	Chat	$10 / M input · $50 / M output

Starter credits

Use GPT-6 Astra free

Your CompanyFabric starter credits cover your first GPT-6 Astra calls at no cost, create a free account, no card required, and the credits apply to GPT-6 Astra and every other model on the key. When they run out, prepaid credits or BYOK (0% fee) take over with no plan to pick.

All ways to use AI models free →

Production-grade

Code samples

import OpenAI from "openai"

const client = new OpenAI({
  baseURL: "https://api.companyfabric.com/v1",
  apiKey: process.env.COMPANYFABRIC_API_KEY,
})

const res = await client.chat.completions.create({
  model: "openai/gpt-6-astra",
  max_tokens: 1024,
  temperature: 0.7,
  messages: [{ role: "user", content: "Say hello from the fabric." }],
})

console.log(res.choices[0].message.content)

Playground

Try it in the browser

Playground$10 in / $50 out per 1M tokens

Model

Max output

Prompt

Comparisons

GPT-6 Astra vs the alternatives

GPT-6 Astra vs Claude Fable 5

Both are top-of-family. Astra brings the larger raw context window and OpenAI's tooling ecosystem; Fable 5 leads on sustained tool-calling reliability inside long agent loops. Route massive-context ingestion to Astra and the highest-stakes agentic turns to Fable, one key, one balance, one string to switch.

GPT-6 Astra vs Claude Opus 5

Opus 5 is the Claude generation's deep-work model at half Astra's token price; Astra answers with a far bigger window and native reasoning-effort control. On a known workload, run both behind the same key and let your eval, not the datasheet, pick per task.

FAQ

Frequently asked questions

How much does the GPT-6 Astra API cost?

$10 / M input · $50 / M output. Every call is metered exactly and shown before you run it.

How do I get a GPT-6 Astra API key?

Create a CompanyFabric account, and one key unlocks GPT-6 Astra and every other model in the library. Free starter credits are included, no subscription, no card required to try it.

Why use GPT-6 Astra on CompanyFabric instead of going direct?

One key, one prepaid balance, and one rate-limit envelope across the whole library, at pricing at parity with or below the direct API. Model switching is a one-line change, and BYOK routing is 0% fee.

Is the API OpenAI-compatible?

Yes, point any OpenAI SDK at api.companyfabric.com/v1 and set model to "openai/gpt-6-astra".

Can I use the output commercially?

Commercial output use permitted per OpenAI terms.

How does billing work?

Prepaid credits via card, or BYOK with your own provider keys at 0% platform fee. No subscription required; balances never expire.

Does GPT-6 Astra support tools, vision, and streaming through CompanyFabric?

Yes, tools, vision, and streaming pass through the OpenAI-compatible endpoint unchanged, and the reasoning_effort parameter is forwarded to OpenAI as-is, so you can dial reasoning depth per request.

How big is the GPT-6 Astra context window?

1,050,000 input tokens with up to 128,000 output tokens per call. Requests over 272k input tokens are billed at the long-context rate for the entire request.

GPT-6 Astra or GPT-5.5, which should I use?

GPT-5.5 is cheaper ($5/$30 per Mtok) and ideal for everyday work; Astra is the reach-for-it tier when a task needs the million-token window or maximum reasoning depth. Both sit behind one key, so the split is a config line, not a second contract.

Provider

About OpenAI

OpenAI publishes the gpt family. Also in this family: GPT-5.5. License: Commercial output use permitted per OpenAI terms.

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