Grok 4 Fast
Grok 4 Fast is a image-generation model from xAI, released September 19, 2025. Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model...
by xAI · 2000K token context window
Best for
- image generation from text
- creative design and ideation
Ways to use Grok 4 Fast in osFoundry
Connect with your own key (BYOK)
Open the key dialog and paste your xAI API key. osFoundry discovers Grok 4 Fast automatically — assign it to a Maestro role (router, direct, orchestrator, or fallback) in the Pipeline tab and it is live in every chat. Your key, your provider account — no token markup.
Use it in a Room App
Room Apps declare AI features in their manifest, then call them with invokeAI:
import { invokeAI } from '@osfoundry/app-sdk'
// 'summarize' is an AI feature declared in your app manifest.
const result = await invokeAI('summarize', userText)
Call it from your own apps
Once a model is wired into your workspace you can host it as an API and reach it from your own services, scripts, or CI — outside osFoundry.
Grok 4 Fast vs similar models
Licence
Hosted — usage subject to provider terms — Hosted-only model — usage governed by the provider's API terms. Bring your own provider key.
No weights distributed; usage subject to provider terms.
Frequently asked about Grok 4 Fast
How much does Grok 4 Fast cost?
Grok 4 Fast is metered at $ 0.200 /1M for input, and $ 0.500 /1M for output. Bring your own xAI API key — osFoundry passes through provider pricing without markup.
Can I use Grok 4 Fast commercially?
Commercial use is allowed with conditions. Hosted-only model — usage governed by the provider's API terms. Bring your own provider key. No weights distributed; usage subject to provider terms.
What is the context window of Grok 4 Fast?
Grok 4 Fast supports a 2000K token context window.
Can I run Grok 4 Fast locally?
No — Grok 4 Fast is hosted only and accessed via the xAI API.
What is Grok 4 Fast best at?
Grok 4 Fast is well-suited to image generation from text, creative design and ideation.
How do I use Grok 4 Fast in osFoundry?
Paste your xAI API key in the key dialog (or deploy the open weights for self-hostable models), assign Grok 4 Fast to a Maestro role in the Pipeline tab, then use it in chat, Room Apps via invokeAI, or your own apps.
Published by xAI on September 19, 2025. Source: https://openrouter.ai/x-ai/grok-4-fast