GPT-5.3 Chat
GPT-5.3 Chat (OpenAI, 2026) is an image-generation model. GPT-5.3 Chat is an update to ChatGPT's most-used model that makes everyday conversations smoother, more useful, and more directly helpful. It delivers more accurate answers with better contextualization and significantly...
by OpenAI · 128K token context window
Best for
- image generation from text
- creative design and ideation
Ways to use GPT-5.3 Chat in osFoundry
Connect with your own key (BYOK)
Open the key dialog and paste your OpenAI API key. osFoundry discovers GPT-5.3 Chat 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.
GPT-5.3 Chat 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 GPT-5.3 Chat
How much does GPT-5.3 Chat cost?
GPT-5.3 Chat is metered at $ 1.75 /1M for input, and $ 14.00 /1M for output. Bring your own OpenAI API key — osFoundry passes through provider pricing without markup.
Can I use GPT-5.3 Chat 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 GPT-5.3 Chat?
GPT-5.3 Chat supports a 128K token context window.
Can I run GPT-5.3 Chat locally?
No — GPT-5.3 Chat is hosted only and accessed via the OpenAI API.
What is GPT-5.3 Chat best at?
GPT-5.3 Chat is well-suited to image generation from text, creative design and ideation.
How do I use GPT-5.3 Chat in osFoundry?
Paste your OpenAI API key in the key dialog (or deploy the open weights for self-hostable models), assign GPT-5.3 Chat to a Maestro role in the Pipeline tab, then use it in chat, Room Apps via invokeAI, or your own apps.
Published by OpenAI on March 3, 2026. Source: https://openrouter.ai/openai/gpt-5.3-chat