Connect ChatGPT

Custom MCP apps in ChatGPT need Developer mode, and Developer mode is available to Pro, Plus, Business, Enterprise and Education accounts on the web; ChatGPT Free cannot add a custom connector. A custom connector's authentication can be OAuth, No Authentication, or Mixed, and ChatGPT cannot present custom API keys, so a pasted key or a custom Authorization header is not an option. IMMA AI's MCP server supports OAuth 2.1 for this reason: turn on Developer mode, add IMMA AI as a custom connector with the MCP URL, then sign in with OAuth, no key copying involved.

Prerequisites

• A ChatGPT plan that supports Developer mode: Pro, Plus, Business, Enterprise or Education, on the web. ChatGPT Free does not have Developer mode.
• An IMMA AI account with access to the workspace you want to connect.

Menu labels can change; if yours differ, follow the linked official guide.

Steps

1. Turn on Developer mode: open Settings > Security and login, then toggle Developer mode on.
2. Create the app: go to ChatGPT Plugins, click the + button, and create a developer-mode app for a remote MCP server:
   • URL: https://api.getimma.com/mcp
   • Authentication: OAuth
   • Supported transports are SSE and streaming HTTP.
3. The app appears under Drafts in your app settings, where you can toggle and refresh its tools. Click Connect to sign in; you are redirected to IMMA AI's OAuth consent screen, which shows the workspace, your profile and the scopes being requested, then back to ChatGPT.
4. To use it in a chat, open the + (Plus) menu in the composer, choose Developer mode, and select the IMMA AI app.

Verify it worked

Once connected, ask ChatGPT:

Call list_accounts and tell me which social accounts are connected.

Common errors

Symptom	Cause	Fix
Connector added but no tools appear	Requested scopes on the OAuth grant do not cover any tool	Re-authorize and confirm the requested scopes match what the connector needs
Authorization loop or redirect fails	Browser blocked a redirect, or popups are disabled	Allow popups for chatgpt.com and retry
Consent denied or canceled	You closed the consent screen or clicked deny	Click Connect again and complete the login
Wrong workspace connected	Chose the wrong workspace on IMMA AI's consent screen	Disconnect the connector and reconnect, picking the right workspace this time

Official docs

• Developer mode guide (primary reference for the steps above)
• MCP servers | OpenAI API
• Plugin/connector authentication
• Developer mode and MCP apps in ChatGPT (help center article; may not load for automated fetchers)