Connect MCPifex to ChatGPT: Web App Setup and Checks

To connect MCPifex to ChatGPT, create a developer-mode app in ChatGPT on the web and use https://mcpifex.com/mcp/<YOUR_MCPX_KEY> as its server URL. The key in the URL is what authenticates you, so you choose No Authentication in ChatGPT's form. Then pick the app in a conversation and try one tool.

Before you connect

You need an MCPifex instance with its tools enabled, a passing Test connection, and an API key. The quickstart covers all of it. Your database password or other credentials stay in the instance. ChatGPT only ever gets the MCPifex key.

As of September 2026, OpenAI documents web developer mode for Pro, Plus, Business, Enterprise and Education accounts. Your workspace policy can restrict it. This page covers ChatGPT on the web only.

Add the app in ChatGPT

1. On ChatGPT web, open Settings → Security and login → Developer mode and enable it if your account and workspace allow it.
2. Open ChatGPT Plugins, use the plus button, and create a developer-mode app named MCPifex with a short description.
3. Set the MCP server URL to https://mcpifex.com/mcp/<YOUR_MCPX_KEY>.
4. Choose No Authentication (or None): the MCPifex key in the URL authenticates the gateway request.
5. Create the connection and review the discovered tools.
6. In a conversation, use the plus menu → Developer mode, select the app, and test one named read-only tool.

These steps follow the OpenAI developer-mode documentation, checked in September 2026. Availability depends on your plan and workspace policy.

Treat this URL like a password: anyone who has it can use every tool enabled on that key. If it leaks, revoke the key, generate a new one and update the app. API keys and authentication also covers the bearer-header form for clients that support it.

Check that it works

Compare the app's tool list with the tools enabled on your instance. The gateway only lists enabled tools, and write tools start off.

Then ask ChatGPT to use one read tool by name. Depending on your instance, that's list_schemas for PostgreSQL, list_properties for Search Console, or trending_now for Google Trends. Look at the real tool result. A description of what the tool could do doesn't prove it ran. The instance's call log in the portal confirms the request arrived.

If it doesn't connect

• No Developer mode option: check your account plan and workspace app policy.
• 401: check the full URL and whether the key was revoked. Generate a new one if needed.
• instance_disabled: the instance is off, often after a plan downgrade.
• connection_revoked: reconnect the Google account in the instance.
• Missing tools: enable them in the instance, refresh the app, and select it for the conversation.

The troubleshooting page explains each error. MCPifex's gateway uses the handshake-based MCP transport. Clients on the current revision interoperate through the spec's backward-compatibility rules.

What to try next

For a real task, see how to pull Search Console data into ChatGPT. For background, read the ChatGPT MCP integration guide. Pick a server from the marketplace. Instance limits are set by your MCPifex plan on the pricing page, not by your ChatGPT plan.