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How can I use apps inside ChatGPT?

Learn how to use your own app in ChatGPT, even before the ChatGPT App Store launches.

How can I use apps inside ChatGPT?

The ChatGPT App Store will soon make installing and sharing apps much easier. Until that arrives, running apps inside ChatGPT still works, but it takes a few more manual steps.

In this post I will walk through how to enable developer mode, link your MCP server as a connector, and then use your app in real chats. You can do all of this with your existing ChatGPT account.

What should I have ready before I start?

Before you touch any ChatGPT settings, make sure you have an MCP server running like https://123.app.yavio.io/mcp

Also keep two limits in mind for now:

  • You can only use your app with your own account in developer mode.
  • Public publishing is not open yet, although submissions will be accepted later this year.

As of November 13th 2025, ChatGPT Apps work on all major paid plans.

How do I turn on developer mode in ChatGPT?

To build and test your own app you first need developer mode in ChatGPT.

  1. Open ChatGPT in your browser.
  2. Go to Settings.
  3. Open Apps & Connectors.
  4. Scroll to Advanced settings at the bottom.
  5. Toggle developer mode on, if your organization policy allows it.

Once developer mode is active you will see a Create button under Settings → Apps & Connectors. This is your entry point to define new apps and connectors.

Screenshot 2025-12-05 at 19.17.20.png

What are the main steps I need to follow?

Here is the flow in one glance:

  1. Enable developer mode in ChatGPT settings
  2. Create a connector that points to your MCP server
  3. Start a new chat and attach your connector as a tool
  4. Test and iterate, refreshing metadata when tools change

How do I create a connector for my MCP server?

With developer mode enabled you can add a connector:

  1. In ChatGPT, open Settings
  2. Go to Connectors.
  3. Click Create.
  4. Fill out the connector metadata:
  5. Connector name, for example “Kanban board”
  6. Description, explaining what the connector does and when to use it
  7. Connector URL, the public HTTPS /mcp endpoint for your server
  8. Click Create to save.

If everything is wired correctly, ChatGPT will fetch your MCP metadata and show the list of tools your server advertises. If it fails, use tools like MCP Inspector or the API Playground to debug requests and responses until the connection works.

How do I try my app directly in a ChatGPT conversation?

Once the connector exists you can start using your app in real chats.

  1. Open a new conversation in ChatGPT.
  2. Click the plus button next to the message box.
  3. Choose More.
  4. Pick your connector from the list of available tools.

Your app is now part of the conversation context. You can prompt ChatGPT as if you were talking to your app. For example, if your app is a Kanban board you might ask “What are my available tasks?” or “Move my ‘Write blog post’ task to In Progress”.

When ChatGPT chooses to call your tools, you will see the tool call payloads in the UI. For write operations you may be asked to confirm the action unless you choose to remember approvals for that conversation.

What happens when I change my tools or descriptions?

You will often update your MCP server while iterating on your app. ChatGPT does not automatically detect these changes, so you need to refresh the metadata.

  1. Update your MCP server and restart it.
  2. In ChatGPT, go to Settings → Connectors.
  3. Open your connector.
  4. Click Refresh.

Check that the tool list and descriptions match your latest version, then try a few prompts to verify the new behaviour.

Can I use my app with other OpenAI clients too?

Yes, once your MCP server is live you can connect it from other clients.

  • API Playground: In the platform playground, open Tools, click Add, choose MCP Server, and paste the same HTTPS endpoint. This is helpful when you want to see raw request and response logs without the full ChatGPT UI.
  • Mobile apps: After you link a connector on ChatGPT web, the same connector appears on ChatGPT mobile as well. This is useful if your app comes with custom components or layouts that you want to validate on smaller screens.

With the connector in place you can move on to validation, experiments, and eventually a rollout through the App Store once it is available.

How can I go faster when building my own ChatGPT App?

If you want to build and test your own app inside ChatGPT in minutes, try Yavio and start creating your own ChatGPT App right now. Our goal is to spend most of your time on the app’s behaviour instead of wiring.