OpenAI has reshaped ChatGPT from a simple conversational assistant into a powerful application platform.
Thanks to the Apps SDK, developers can now build apps that run directly within ChatGPT’s interface, extending its capabilities and connecting seamlessly with external services and websites.
Learn more on OpenAI’s official post
In this article, we’ll explore how to develop a ChatGPT app step by step, provide direct links to the SDK and documentation, and analyze how this evolution will impact the development of websites and digital services across Europe and beyond.
What Is the Apps SDK- Technical Overview
How It Works
The Apps SDK is built around two main components:
- MCP Server (Model Context Protocol)– enables ChatGPT to send and receive structured data from your app, as if it were a native extension.
- Embedded Web Interface– an optional but powerful UI widget that can render visual content (forms, charts, product cards) directly inside the chat window.
Official Docs: developers.openai.com/apps-sdk
Example Repository: openai/openai-apps-sdk-examples
Intro Tutorial: freeCodeCamp- How to Use the ChatGPT Apps SDK
Technical Guide to Development
- Ideation and Use Case Definition
Start by defining what your app will do– for instance, connect to a SaaS platform, enhance a website, or provide client dashboards.
In a European or Italian context, examples include booking systems, SME productivity tools, product configurators, technical translators, or analytics dashboards.
- Setting Up the Environment
Clone the official example repository:
git clone https://github.com/openai/openai-apps-sdk-examples.git
Install dependencies (pnpm install, npm install, or yarn install) and launch the starter project.
- Creating the MCP Server
Implement an endpoint (e.g., /mcp) that exposes tools (functions) and resources (data).
ChatGPT will communicate with it through HTTPS.
For local testing, you can use tunneling services like ngrok or localtunnel.
- Building the UI
You can use React, Vue, or vanilla JS to create a widget that will appear inside the chat.
This is especially useful for visual interactivity- charts, buttons, product selectors, or form submissions.
- Authentication and User State
If your app accesses private services, integrate session handling and authentication via OAuth2 or API tokens.
A great reference: Stytch- Guide to Authentication for the OpenAI Apps SDK
- Testing and Publishing
Enable Developer Mode in ChatGPT (Settings → Apps & Connectors → Developer Mode) to test your app locally.
Once ready, deploy your server on a secure HTTPS endpoint and verify GDPR compliance before going live.
The Impact on Web and Service Development
A New Conversational Channel
ChatGPT Apps introduce a new access layer to digital services: users can interact with your business through natural language, without leaving the chat.
This turns every digital service into a conversation-first experience.
Business Opportunities
- Faster onboarding for clients and customers.
- Seamless access to your services across devices.
- New distribution channels for startups and agencies.
- Stronger user engagement through personalized, AI-driven experiences.
Key Challenges
- Secure API integration and data handling.
- Compliance with EU data protection laws (GDPR).
- Careful design of UX for chat-based interaction.
- Optimized performance and clear information hierarchy.
Real-World Scenarios (Italy / Europe)
Here are practical ways Italian and European businesses can leverage ChatGPT Apps:
- Tourism and Hospitality
A tour operator or hotel chain can build an app that lets users book trips, check itineraries, and view real-time availability directly inside ChatGPT.
Example: “Show me weekend offers for the Amalfi Coast.”
- Legal and Accounting Services
A consulting firm can create an app that answers questions about tax deadlines, legal documents, or compliance forms.
Example: “Calculate my 2025 flat-rate tax as a freelancer in Italy.”
- Real Estate
An agency could develop a ChatGPT App to search properties by location, price, and type, displaying interactive cards with images and links to listings.
- E-Commerce and Retail
Online stores can build apps that recommend products, assist in purchasing decisions, and manage orders– all through conversational queries like:
“Find the best smartphone under €400.”
- Healthcare and Wellness
Private clinics or wellness centers can integrate assistants that schedule appointments, suggest treatments, and sync with their internal calendars.
- Education and Coaching
Training institutions can offer apps that manage course registrations, online tutoring, and personalized learning paths.
Example: “Show me available Project Management courses in Rome this month.”
- Public Administration and Local Government
A municipality could deploy a ChatGPT App to answer citizen inquiries on taxes, documents, and public services- connecting directly to its digital administration systems.
The OpenAI Apps SDK turns ChatGPT into an open, modular platform where developers can embed their services directly within a conversational context.
For the European market- especially in Italy- this shift represents a massive opportunity for automation, digital transformation, and customer engagement.
For developers and digital consultants, the best approach is to start small: build a prototype using a Node.js server, expose an MCP endpoint, and test with Developer Mode.
From there, ChatGPT can become the new conversational frontend for your business.
