OpenAI · MultimodalReleased 2025-04-16

o3-fast

openai/o3-fast id

OpenAI's o3 is their most powerful reasoning model, setting new state-of-the-art benchmarks in coding, math, science, and visual perception. It excels at complex queries requiring multi-faceted analysis, with particular strength in analyzing images, charts, and graphics.

Tool useReasoningChatWeb searchStructured output

Type

Use o3-fast

# Drop-in OpenAI-compatible client
$ import { generateText } from 'ai'
$ 
$ const { text } = await generateText({
$   model: 'openai/o3-fast',
$   baseURL: 'https://synapse.garden/api/v1',
$   apiKey: process.env.MG_KEY,
$   prompt: 'Why is the sky blue?',
$ })

200K

CONTEXT WINDOW

100K

MAX OUTPUT

$3.85/M

INPUT · PER M

$15.40/M

OUTPUT · PER M

PRICING

List prices, every modality.

Rate	Per million tokens · USD
Input	$3.85/M
Output	$15.40/M
Cache read	$0.963/M

Honest list pricesHow we calculate prices

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gpt-6-luna-fastGPT-6 Luna is OpenAI's efficient reasoning model for focused, high-volume tasks. It accepts text and images, generates text, and supports a 1,050,000-token context window with up to 128,000 output tokens. Configurable reasoning effort, structured outputs, prompt caching, and Responses API tools support cost-sensitive applications, coding tasks, and automated workflows.TOOLSREASONINGJSONWEB
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gpt-6-solGPT-6 Sol is OpenAI's reasoning model for complex coding and agentic workflows. It accepts text and images, generates text, and supports a 1,050,000-token context window with up to 128,000 output tokens. Configurable reasoning effort, structured outputs, prompt caching, and Responses API tools make it suited to software development and multi-step automation.TOOLSREASONINGJSONWEB
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$11.00/M
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gpt-6-sol-fastGPT-6 Sol is OpenAI's reasoning model for complex coding and agentic workflows. It accepts text and images, generates text, and supports a 1,050,000-token context window with up to 128,000 output tokens. Configurable reasoning effort, structured outputs, prompt caching, and Responses API tools make it suited to software development and multi-step automation.TOOLSREASONINGJSONWEB
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gpt-live-1Our premier model for natural, expressive voice conversations with smooth interruption handling.
Input
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gpt-image-2.5-flareGPT Image 2.5 Flare generates images from text and image inputs, optimized for fast, high-quality everyday image generation.TOOLS
Input
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Output
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Context
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Input
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Output
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Context
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Input
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gpt-6-astra-fastGPT-6 Astra is OpenAI's most capable model for complex reasoning, coding, computer use, research, and document creation.TOOLSREASONINGWEBJSON
Input
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Output
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gpt-5.6-lunaGPT-5.6 Luna is a fast, affordable GPT-5.6 model that brings strong capability at the lowest cost in the series.REASONINGTOOLSWEBJSON
Input
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Output
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gpt-5.6-luna-fastGPT-5.6 Luna is a fast, affordable GPT-5.6 model that brings strong capability at the lowest cost in the series.REASONINGTOOLSWEBJSON
Input
$0.440/M
Output
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Context
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gpt-5.6-solGPT-5.6 Sol is the flagship of OpenAI's GPT-5.6 series, its most capable model for long-horizon agentic work across coding, biology, and cybersecurity.REASONINGTOOLSWEBJSON
Input
$4.40/M
Output
$22.00/M
Context
1.1M

FAQ · O3-FAST

Frequently asked

01 / 04

How do I call o3-fast from my code?

Use the OpenAI or Anthropic SDK and point baseURL at https://synapse.garden/api/v1. Set model: ‘openai/o3-fast’ and supply your Synapse Garden API key. No code changes beyond the base URL.

02 / 04

How much does o3-fast cost?

Input: $3.85/M per million tokens. Output: $15.40/M per million tokens. The free tier includes a million tokens every month at no cost.

03 / 04

What's the context window for o3-fast?

o3-fast supports a context window of 200K tokens, with a maximum output of 100K tokens.

04 / 04

Do I need a separate Anthropic or OpenAI account?

No. Synapse Garden is the single API surface — one key gives you OpenAI, Anthropic, Google, Meta, Mistral, DeepSeek, xAI, Cohere, and more. Billing, rate limits, and audit logs are unified.

READY

Try o3-fast in three minutes.

Sign up, create a key, drop our base URL into your existing client. The free tier includes a million tokens every month — no credit card.

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