ChatGPT & Claude (MCP)
How to Connect an MCP Server to ChatGPT
You have an MCP server URL, you open ChatGPT's Plugins page to add it as a custom plugin, and there is no plus button. Nothing is broken and you are not on the wrong page. Adding a custom plugin is gated behind Developer mode, and until that is on, the button is simply not rendered. Developer mode lives under Settings, then Security and login, which is not where most walkthroughs say to look. Turn it on there, return to Plugins, and the plus button appears. From there you name the plugin, paste the app's MCP URL, which is the app's address followed by /mcp, and pick an authentication type. If you do not know which one the server uses, try OAuth first; ChatGPT tells you immediately if it is not an OAuth app, and you switch to no auth. Accept the risk warning, wait for it to connect, and ChatGPT lists every tool the plugin gives it. To use it, type @ and the name you gave the plugin, select it, and ask for what you want done. This walkthrough adds the Carly plugin as the example, but the flow is the same for any app that gives you an MCP URL. One caution that is not optional: a connected server can act on your behalf, and some are able to create, update or send things rather than only read. Connect servers you trust, check the URL, and read what the connection is asking for before you accept it. Menu labels and availability can also vary by account or workspace policy.
Step by step
- 01
Know why the plus button is missing
The Plugins page hides the add button until Developer mode is on. If you have a server URL and nowhere to paste it, this is almost always the reason rather than a plan or a bug.
- 02
Turn on Developer mode under Security and login
Click your profile picture, open Settings, choose Security and login, and scroll to Developer mode. Older guides send you to Connectors and then Advanced; that path no longer matches the current interface. On a managed workspace the toggle itself can be hidden by admin policy.
- 03
Return to Plugins and click the plus
Back on the Plugins page the plus button is now there. This is the point the whole setup was stuck on.
- 04
Find the app's MCP URL
What you are looking for is the app's address followed by /mcp. MCP stands for model context protocol, and it is how another application talks to ChatGPT. If an app gives you a URL ending in /mcp, you can add it as a custom plugin.
- 05
Name the plugin and paste the URL
Give it a clear name you will recognize later, because that name is how you call it in chat, then paste the MCP URL you copied.
- 06
Pick an authentication type
If you do not know which type the server uses, try OAuth first. ChatGPT tells you right away if it is not an OAuth application, and you can switch to no auth and try again. You can try more than one.
- 07
Accept the warning and wait for it to connect
ChatGPT shows what the connection can reach. A server may be able to create, update or send on your behalf, not just read, so accept only for a server you trust and a URL you have checked. Once it connects, press Connect and scroll the list to see every tool the plugin gives ChatGPT.
- 08
Use it with @ in a conversation
Type @ followed by the name you gave the plugin, select it, and ask for whatever you want done. ChatGPT can now talk to the app you connected.
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