ChatGPT MCP: How to Add a Custom MCP Server

ChatGPT can connect to MCP servers. MCP (Model Context Protocol) is the open standard for plugging tools into AI apps, so ChatGPT can call an outside tool in the middle of a chat and show you the result. You add a server by its URL: in recent versions of ChatGPT that means Plugins in the sidebar, Add, then Add custom MCP server. ChatGPT only takes remote servers (an HTTPS URL), not programs running on your computer. Whether you see the option depends on your plan and, in a business workspace, on your admin. Below are the steps, what can block you, and a worked example with a carousel renderer.

What is MCP in ChatGPT?

MCP is how ChatGPT talks to tools it does not have built in. The tool runs on someone else’s server and describes what it can do; ChatGPT decides when to call it, sends the inputs, and shows you what comes back.

Term	What it means in ChatGPT
MCP server	A remote service with one or more tools, reached by an HTTPS URL
Custom MCP server	One you add yourself by URL
Developer mode	The setting OpenAI uses to gate custom MCP servers on some accounts
OAuth	The sign-in most servers use, so you never paste a password into ChatGPT

The same server often works in Claude, Cursor and other MCP apps too, because the protocol is shared.

Can every ChatGPT account add an MCP server?

Not always. OpenAI has changed where the option lives and which plans get it several times. Its help article on developer mode and MCP apps describes it for Business, Enterprise and Edu workspaces, where an admin turns developer mode on and can limit who uses it. On other accounts, the menu names and availability have moved between releases. If you can’t find the option, check OpenAI’s current help article for your plan before assuming the server is broken.

How do you add a custom MCP server to ChatGPT?

The flow as it looked in October 2026 on an account with the option:

Get the server’s URL from the tool’s setup page.
In ChatGPT, open Plugins in the sidebar, click Add in the top right and choose Add custom MCP server.
Give it a name, keep Connection on Server URL and paste the URL.
Leave Authentication on OAuth if the tool uses a sign-in (most do).
Tick I understand and want to continue and click Create as a plugin.
A window opens: sign in to the tool and choose Allow.
In a chat, pick the tool from the tools menu and ask for what it does.

If your screen differs, look for “custom MCP server”, “connector” or “developer mode” in settings; the names have shifted between versions.

What is a good MCP server to test with?

One whose result you can see. Karou is a carousel renderer: ChatGPT writes the slides and Karou turns them into images. They come back in the chat with download links for a PNG per slide, a ZIP and a PDF. If the thumbnails show up, the connection works. And you get a carousel without pasting slides into an editor.

Create a free Karou account.
Add a custom MCP server named Karou with the URL https://karou.si/mcp and OAuth.
Sign in to Karou and choose Allow.
Ask for one of your carousel post ideas: “Use Karou to make an Instagram carousel, 6 slides, clean template, on the 3 things I check before I hire a freelancer.” Add your notes.

ChatGPT writes the hook slide, one idea per slide and a closing slide, then calls Karou’s create tool. Posting the result is the same as any carousel: see how to make a carousel on Instagram. To change something, say so (“make slide 2 shorter”); the edit tool re-renders the same carousel and edits do not count against the daily limit. Karou never writes for you and sends nothing to a model: ChatGPT writes, Karou renders. The prompt that gets the best slides is in ChatGPT carousel prompt, and setup for Claude and Cursor is in connect Karou to Claude, ChatGPT and Cursor.

What should you check before adding an MCP server?

Who runs it. A custom server is not reviewed by OpenAI. Add the ones you would trust with an account.
What its tools can do. Reading, creating files and acting on your behalf are different levels of risk.
How it signs in. OAuth lets you revoke access from the tool’s side later.

How does ChatGPT MCP compare to Claude connectors?

Same protocol, different screens. In Claude, a remote MCP server is a custom connector, and Anthropic lists custom connectors on every Claude plan, with one on Free. In ChatGPT, it is a custom MCP server or app, gated by plan and developer mode. Most servers, Karou included, work in both. Claude connectors has the Claude steps.

FAQ

Does ChatGPT support local MCP servers?

The ChatGPT app connects to remote servers by URL. Local servers (programs on your own machine) are for developer tools like Claude Code or editors.

Why don’t I see the option to add an MCP server?

Usually the plan or the workspace. On business workspaces an admin has to enable developer mode. Check OpenAI’s help article for your account type.

Is it free to use an MCP server in ChatGPT?

The connection itself costs nothing extra; the tool has its own pricing. Karou’s free plan renders 3 carousels a day with a small watermark, enough to test the connection on real posts. Pro removes the watermark and adds your own templates (plans): free for 14 days, then $12 a month or $97 a year.

Can ChatGPT make carousels without an MCP server?

It can write the slides. Turning them into images needs an editor or a renderer. AI carousel generator explains the options.

Start free and try Karou as your first MCP server in ChatGPT.