OpenAI API Pricing: GPT-6 Astra, Sol and Luna per 1M Tokens

OpenAI’s API charges USD 10 per 1M input tokens and USD 50 per 1M output tokens for GPT-6 Astra, with cached input at USD 1. GPT-6.1 Sol and GPT-6 Sol cost USD 2 and USD 10, and GPT-6 Luna costs USD 0.10 and USD 0.50. With three input tokens for every output token, 5M tokens on GPT-6 Astra cost USD 100 at OpenAI’s standard rates. Capriole AI Premium costs USD 8 per month for unlimited web chat with GPT-6 Astra, Claude Fable 5.1, Claude Opus 5.5, and Gemini 4 Argon. Its API serves GPT-6 Astra through OpenAI Responses and Chat Completions at USD 8 per 5M tokens of any supported model, up to 92% less than official API prices. One API key works in your own apps and in coding agents such as Codex.

OpenAI API prices per 1M tokens

OpenAI publishes these standard rates on its API pricing page. All prices are in USD per 1M tokens, for prompts up to 272K input tokens.

Model	API model ID	Input	Cached input	30-min cache write	12-hour cache write	Output
GPT-6 Astra	`gpt-6-astra`	USD 10	USD 1	USD 12.50	USD 25	USD 50
GPT-6.1 Sol	`gpt-6.1-sol`	USD 2	USD 0.10	USD 2.50	USD 5	USD 10
GPT-6 Sol	`gpt-6-sol`	USD 2	USD 0.20	USD 2.50	USD 5	USD 10
GPT-6 Luna	`gpt-6-luna`	USD 0.10	USD 0.01	USD 0.125	USD 0.25	USD 0.50

OpenAI’s pricing and model pages list the rules that change these rates:

Batch and Flex: Both cost 50% of standard rates. GPT-6 Astra costs USD 5 input and USD 25 output.
Long prompts: A request with more than 272K input tokens pays 2 times the input and cache rates and 1.5 times the output rate for the full request.
Fast mode: Costs 2 times standard rates. GPT-6 Astra in fast mode costs USD 20 input and USD 100 output.
Regional processing: Adds 10% where it is available.

What 1M and 5M tokens cost

These examples use standard rates, no caching, prompts under 272K tokens, and three input tokens for every output token.

official_cost = input_millions × input_price + output_millions × output_price

Tokens	Input / output	GPT-6 Astra	GPT-6.1 Sol or GPT-6 Sol	GPT-6 Luna	Capriole AI, any model
1M	750K / 250K	USD 20	USD 4	USD 0.20	USD 1.60
5M	3.75M / 1.25M	USD 100	USD 20	USD 1	USD 8

On GPT-6 Astra, 5M tokens cost 3.75 × USD 10 + 1.25 × USD 50 = USD 100, so Capriole’s USD 8 is 92% less. On GPT-6.1 Sol and GPT-6 Sol, USD 8 is 60% less. GPT-6 Luna is cheaper on OpenAI directly, at USD 1 for the same workload, so Capriole pays off when your work runs on Astra or Sol. Capriole sells API tokens in 5M packs; the 1M figure is one fifth of a pack, shown for comparison. Capriole’s charged-token formula has no long-prompt tier, so a 300K-token prompt counts at the same rate per token as a short one. Start chatting free or get an API key.

How caching and batch change the comparison

Cached input: OpenAI charges 10% of the input rate, USD 1 per 1M cached tokens on GPT-6 Astra. Capriole also counts cached input at 10%, which works out to USD 0.16 per 1M cached tokens. Charged tokens explained shows the formula.
Cache writes: OpenAI charges 1.25 times input for a 30-minute cache write and 2.5 times input for a 12-hour cache write. Capriole counts every uncached input token, including cache writes, at the normal rate.
Batch and Flex: At half price, the 5M-token GPT-6 Astra example costs USD 50. Capriole has no batch endpoint, and its USD 8 is still 84% less for that workload.

For a 5M-token test that also includes OpenRouter’s credit fee, see the AI API cost comparison. For Claude Fable 5.1 and Opus 5.5, see Claude API pricing; for Gemini 4 Argon, see Gemini API pricing.

Call GPT-6 Astra through Capriole’s API

Capriole’s API is compatible with OpenAI Responses at POST /v1/responses and OpenAI Chat Completions at POST /v1/chat/completions. Set the OpenAI SDK base URL to https://api.caprioletech.com/v1.

openai-latest selects GPT-6 Astra, so your configuration follows the current recommended OpenAI model.
On Responses, native IDs such as gpt-6-astra and prefixed IDs such as openai/gpt-6-astra select the same model.
Chat Completions accepts openai-latest and the model IDs that GET /v1/models returns.

import os

from openai import OpenAI

client = OpenAI(
    api_key=os.environ["CAPRIOLE_AI_API_KEY"],
    base_url="https://api.caprioletech.com/v1",
)

response = client.responses.create(
    model="openai-latest",
    input="Write a release note for this change.",
)
print(response.output_text)

Each key allows 300 requests per minute. See the Responses reference and the Chat Completions reference for every accepted model ID, and the Codex setup to run Codex on your Capriole key.

What USD 8 a month includes

Besides unlimited web chat on every supported model, Premium includes 5M API tokens a month for apps and coding agents; plans and limits covers top-ups, Team, and free web chat.

When the official API fits better

Go to OpenAI directly when your workload runs only on GPT-6 Luna, or when you need the Batch API, regional processing, or a contract with OpenAI itself.

Frequently asked questions

How much does GPT-6 Astra cost?

GPT-6 Astra costs USD 10 per 1M input tokens, USD 1 per 1M cached input tokens, and USD 50 per 1M output tokens. Batch and Flex requests cost half.

Which GPT-6 model is the cheapest?

GPT-6 Luna, at USD 0.10 per 1M input tokens and USD 0.50 per 1M output tokens.

Does OpenAI charge more for long prompts?

Yes. A request with more than 272K input tokens pays 2 times the input and cache rates and 1.5 times the output rate for the whole request.

What does `openai-latest` mean on Capriole AI?

openai-latest points to GPT-6 Astra. It works on /v1/responses and /v1/chat/completions.

Can I use Codex with a Capriole AI key?

Yes. Codex connects through the Responses API with a custom model provider. The Codex setup has the full configuration.

Start with Capriole AI

Start chatting free with no account, or get an API key with Premium. The API quickstart covers your first request.

Official sources

OpenAI: API pricing
OpenAI: GPT-6 Astra, GPT-6.1 Sol, GPT-6 Sol, and GPT-6 Luna model pages

Capriole AI plan, top-up, and charged-token facts on this page are maintained as first-party documentation.

​OpenAI API prices per 1M tokens

​What 1M and 5M tokens cost

​How caching and batch change the comparison

​Call GPT-6 Astra through Capriole’s API

​What USD 8 a month includes

​When the official API fits better

​Frequently asked questions

​How much does GPT-6 Astra cost?

​Which GPT-6 model is the cheapest?

​Does OpenAI charge more for long prompts?

​What does openai-latest mean on Capriole AI?

​Can I use Codex with a Capriole AI key?

​Start with Capriole AI

​Official sources