The way we build apps is fundamentally changing. With the introduction of apps in ChatGPT and the OpenAI Apps SDK, developers and businesses can now create interactive experiences that live directly inside ChatGPT's interface—reaching over 800 million users worldwide.
But here's the challenge: building a ChatGPT app from scratch requires backend development, MCP server setup, UI widget creation, and deployment infrastructure. That's where ChatGPT app builders come in—tools that simplify or eliminate the coding required to ship AI-powered apps.
In this guide, we'll explore what ChatGPT app builders are, compare the best options available in 2025, and help you choose the right approach for your project.
What Is a ChatGPT App Builder?
A ChatGPT app builder is a platform or tool that helps you create apps that integrate with ChatGPT. These apps can:
- Expose custom tools that ChatGPT can call (search databases, create tasks, send messages)
- Render interactive widgets directly in the conversation
- Connect to your data via APIs, databases, or third-party services
- Authenticate users through OAuth to access personalized data
The term "ChatGPT app builder" can refer to different things depending on context:
- No-code platforms that let you build apps visually without writing code
- Low-code frameworks that simplify MCP server development
- The Apps SDK itself, which is the official OpenAI developer toolkit
- AI coding assistants like ChatGPT that help generate app code
Why Build Apps for ChatGPT?
OpenAI introduced apps in ChatGPT in 2025, powered by the Model Context Protocol (MCP). This represents a major shift in how AI applications work:
Massive distribution
ChatGPT has over 800 million users. Building an app means your tool can be discovered and used by this massive audience—without requiring users to download anything or visit your website.
Natural language interface
Users interact with your app through conversation. They don't need to learn a new interface—they just ask ChatGPT to do something, and your app responds.
Context-aware interactions
ChatGPT understands the conversation context and can intelligently decide when to call your app's tools. This creates seamless, intelligent workflows.
Interactive UI in chat
Unlike simple API integrations, ChatGPT apps can render rich, interactive widgets—forms, tables, maps, charts—directly in the conversation.
ChatGPT apps are different from Custom GPTs. While GPTs are essentially customized prompts, apps have backend servers, can take real actions, and render interactive interfaces. Apps are built on MCP and can connect to any external service.
Three Approaches to Building ChatGPT Apps
There are fundamentally three ways to build a ChatGPT app, each with different tradeoffs:
1. Code from scratch (Full control)
Build your own MCP server using the official TypeScript or Python SDK. This gives you complete control over your app's functionality, but requires:
- Backend development skills (Node.js or Python)
- Understanding of the MCP protocol
- Server hosting and deployment
- OAuth implementation for user authentication
- Ongoing maintenance and updates
Best for: Teams with developers who need custom functionality or complex integrations.
2. Low-code with automation platforms
Wire the Apps SDK to low-code backends like n8n, Make, or Zapier. You still write some code for the MCP server, but the business logic runs on visual automation tools.
- Faster prototyping than pure code
- Built-in connectors for popular services
- Visual workflow editors
- Still requires MCP server setup
Best for: Technical users who want speed without building everything custom.
3. No-code builders (Fastest)
Use a visual platform that handles MCP server generation, hosting, and deployment automatically. You design your app through a drag-and-drop interface.
- No coding required
- Built-in hosting and SSL
- Visual tool and UI design
- Pre-built templates for common use cases
Best for: Non-technical founders, business users, or anyone who wants to ship fast.
Comparison: Code vs No-Code vs Low-Code
| Factor | Full Code | Low-Code | No-Code |
|---|---|---|---|
| Time to launch | Weeks to months | Days to weeks | Hours to days |
| Technical skills | Full-stack development | Basic coding + APIs | None required |
| Customization | Unlimited | High | Template-based |
| Maintenance | Self-managed | Partially managed | Fully managed |
| Cost | Dev time + hosting | Platform fees + hosting | Subscription |
| Scalability | You control it | Platform-dependent | Platform handles it |
Top ChatGPT App Builder Tools in 2025
Here's a breakdown of the leading tools for building ChatGPT apps, organized by approach:
Official SDKs (For developers)
OpenAI Apps SDK — The official toolkit for building ChatGPT apps. It extends MCP with UI widgets, authentication, and directory submission. Open source and well-documented.
- Languages: TypeScript, Python
- Requires: Backend development skills
- Best for: Custom, production-grade apps
MCP TypeScript/Python SDK — The underlying protocol SDK from Anthropic. More flexible but requires more setup than the Apps SDK.
Low-code platforms
n8n + MCP — Wire your MCP tools to n8n workflows. Good for teams already using n8n for automation.
Make (Integromat) — Visual automation platform that can serve as a backend for MCP tools.
Vercel + Apps SDK — Deploy MCP servers on Vercel with preview deployments and instant rollbacks.
No-code builders
Agentappbuilder — Visual builder specifically designed for ChatGPT and Claude apps. Handles MCP generation, hosting, and deployment automatically.
- Visual tool designer
- Built-in database
- No coding required
- Multi-platform (ChatGPT + Claude)
DrapCode — No-code platform with ChatGPT API integration for building AI-powered web apps (not native ChatGPT apps).
Bubble + OpenAI — Build web apps with AI features using Bubble's plugin ecosystem. Not native ChatGPT integration but good for AI-enhanced apps.
The OpenAI Apps SDK Explained
The Apps SDK is OpenAI's official framework for building ChatGPT apps. It builds on the Model Context Protocol (MCP) and adds:
Inline UI widgets
Your app can render interactive components (forms, lists, cards, maps) directly in the ChatGPT conversation. Widgets are built with HTML/CSS/React and communicate through window.openai.
Tool definitions
Define tools with JSON Schema that ChatGPT can call. Each tool has a name, description, input parameters, and handler function.
Authentication
Built-in OAuth support lets users connect their accounts (Google, Slack, your custom auth) so your app can access personalized data.
App directory submission
Once your app is ready, you can submit it for review and publication in the ChatGPT app directory.
Basic Apps SDK structure
your-chatgpt-app/
├── server/
│ └── src/index.ts # MCP server with tools
├── web/
│ └── widget.html # UI component
├── package.json
└── README.mdThe server exposes tools via MCP, and the widget renders in ChatGPT's iframe. When a user interacts with your widget, it can call tools and update the display.
Build ChatGPT apps without code
Agentappbuilder lets you create professional ChatGPT apps visually. Define tools, design interfaces, and deploy—all without writing code.
Join the waitlistHow to Choose the Right Builder
The best approach depends on your situation. Ask yourself:
Do you have developers on your team?
Yes: Consider the Apps SDK for maximum flexibility. Your team can build exactly what you need.
No: Use a no-code platform to ship without hiring developers.
How fast do you need to launch?
This week: No-code is your only realistic option for a quick turnaround.
This month: Low-code or code approaches become viable.
No rush: Take time to build a custom solution if you need specific features.
What's your budget?
Limited: Open-source SDK is free. You pay only for hosting.
Moderate: No-code platforms typically charge $20-100/month.
Enterprise: Custom development gives you full ownership but higher upfront cost.
How complex is your app?
Simple (forms, lists, basic actions): No-code handles this well.
Medium (API integrations, workflows): Low-code or no-code with custom extensions.
Complex (real-time data, custom logic): Full code approach recommended.
Best Practices for ChatGPT App Development
Regardless of which builder you choose, follow these practices:
Design for conversation
Your app lives inside a chat interface. Design tools and responses that feel natural in conversation. Write clear tool descriptions so ChatGPT knows when to use them.
Keep widgets focused
Don't try to cram your entire web app into a widget. Focus on specific tasks and keep the UI simple.
Handle errors gracefully
Network issues happen. Show friendly error messages and provide fallback options.
Test with real users
Enable Developer Mode in ChatGPT and test your app with different prompts. Users will phrase requests in unexpected ways.
Iterate quickly
The beauty of ChatGPT apps is rapid iteration. Ship a minimal version, gather feedback, and improve.
Conclusion
ChatGPT apps represent a new paradigm for software distribution. Instead of competing for downloads in app stores, you can reach users where they already spend time—inside ChatGPT.
The right builder depends on your technical skills, timeline, and requirements:
- Developers should explore the OpenAI Apps SDK for full control
- Technical teams can leverage low-code platforms for faster iteration
- Non-technical users should use no-code builders like Agentappbuilder to ship without code
The ecosystem is young and evolving rapidly. The teams that start building now will have a significant head start as ChatGPT apps become mainstream.