DocumentationLLM Apps

Test your LLM App as a ChatGPT plugin test-in-chatgpt

Last update: October 19, 2026
IMPORTANT
Adobe LLM Apps is currently in Beta.
Features, workflows, and UI shown here do not necessarily represent the final state of the product. To join the Beta, send an email to llm-apps-beta@adobe.com.

After deployment, your LLM App exposes an MCP server URL. Add this URL to ChatGPT as a plugin, then test the generated actions and widgets.

In this guide: Learn how to connect your deployed app to ChatGPT and test its actions and widgets in a conversation. Refresh the connection after changing the app.

Plan requirements

Use an account and workspace that permit adding custom MCP servers. Availability and administrator controls vary by account and workspace. See OpenAI’s current Connect and test your plugin documentation.

Check access to custom MCP servers

Open ChatGPT Plugins and check that your account allows adding a custom MCP server. If your account requires developer mode, enable that mode using your account’s controls. If the custom MCP server option is missing or blocked, ask your workspace administrator.

Copy the MCP server URL

In LLM Apps:

  1. Open the App Detail page.
  2. Find Test the app.
  3. Under Stage environment, select Copy URL.

Create the plugin

  1. Open chatgpt.com/plugins.

  2. Select +, then Add custom MCP server.

  3. Configure the connection:

    • Name — the plugin name.
    • Description — optional.
    • Choose the public server connection method and enter your app’s full HTTPS MCP server URL.
    • Choose the authentication method that matches your app. For a public app with authentication disabled, use No Auth where offered.
    note
    NOTE
    If you have turned on end-user authentication, select OAuth when every action is set to Required, or Mixed for a combination of public and protected actions, where those choices are offered. See Authenticate end users with your own identity provider.

  4. Select I understand and want to continue.

  5. Select Create as a plugin.

  6. Review the discovered tools and metadata, then install or connect the resulting plugin. Complete sign-in if your app requires it.

OpenAI owns the setup UI, and its layout may vary by account. Follow the current connection instructions if the displayed labels differ.

Test the plugin

  1. Start a new chat.
  2. Type @ in the prompt box and select the installed plugin.
  3. Ask a question that matches one of the generated actions. For example: Show me some coffee.

Illustrative ChatGPT response — a Frescopa action returns product cards in the conversation

Verify that:

  • ChatGPT invokes the expected action.
  • The widget displays the expected sample data.
  • The text response matches the widget.
  • Widget controls work as expected.

Also test invalid input, empty results, unrelated prompts that do not call for the app, and actions that change data. Review each confirmation and authentication prompt rather than approving all requests in advance.

Refresh after app changes

After changing action descriptions, inputs, authentication, or widget configuration:

  1. Deploy the updated app to the same environment.
  2. Open its connection on ChatGPT Plugins and select Refresh.
  3. Verify that the advertised actions changed.
  4. Start a new conversation and repeat the affected tests.

What’s next

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