How to add a tool to ChatGPT, Claude and Gemini

To add a tool to ChatGPT, Claude or Gemini, you paste the tool’s MCP server address into the app’s settings and sign in to the service. Coding tools such as Cursor, VS Code, Claude Code and Codex take the same address through a settings page, a config file or one terminal command. Which plans can do it differs a lot.

We checked every step below against each maker’s help pages on 17 October 2026. Menus change often, so if a button has moved, search the app’s help for “custom connector” or “MCP”. We use https://example.com/mcp as a stand-in; use the address your tool’s maker gives you.

What do you need before you start?

• The server address. The tool’s maker publishes it, usually in its docs. It has to be reachable over the internet: ChatGPT and Claude connect to servers remotely, so one that runs only on your own computer needs extra setup.
• An account with the service, for the sign-in step.
• A plan that allows it. See the table below. On work accounts, an admin may have to add the tool first.

New to all this? Start with what MCP is, in plain English.

Which apps and plans let you add a tool?

App	Who can add one (October 2026)	Where
ChatGPT	Business, Enterprise and Edu in full, with admin control; Pro with read and fetch only	Web only
Claude	Free (one connector), Pro and Max; on Team and Enterprise, an owner adds it first	Claude on the web, Cowork and Claude Desktop
Gemini	Personal Google Accounts in the US, aged 18 and over, in English, with Keep Activity on	Added on the web, used on web and mobile
Cursor	No plan limits listed; Enterprise admins can restrict which servers run	Cursor
VS Code	No plan limits listed; organisations can manage access centrally	VS Code
Claude Code	No plan limits listed on its MCP page	Terminal
Codex	No plan limits listed on its MCP page	Terminal, shared with the ChatGPT desktop app

How do I add an MCP server to ChatGPT?

On the web:

1. Open Plugins.
2. Choose the + button, then Add custom MCP server.
3. Enter a name and, if you like, a description.
4. Under Connection, paste the server address, such as https://example.com/mcp.
5. Set up authentication, so that you can sign in to the service.
6. Read the risk warning and tick I understand and want to continue.
7. Choose Create as a plugin, then review the tools it found.

To use it, install the plugin it creates, then type @ in a new chat and pick it. According to OpenAI’s help article, this works on the web only. On Business, only admins and owners can add a server; on Enterprise and Edu, admins can let selected members do it. Pro users can connect servers with read and fetch permissions only.

How do I add a custom connector to Claude?

On Pro or Max, and on Free, which allows one:

1. Go to Customize, then Connectors.
2. Choose + Add, then Add custom connector.
3. Enter a name and the server address, then choose Continue.
4. Check the sign-in settings Claude detected and choose Continue.
5. Under Authentication, choose Sign in now, Sign in when needed or No sign in.
6. Leave the advanced options alone unless the tool’s docs say otherwise, choose Add and sign in to the service.

Turn the connector on for a chat from the + button, then Connectors. On Team and Enterprise, an owner first adds it under Organization settings, then Connectors, and members then choose Connect (Claude’s help centre).

How do I add a custom app to Gemini?

1. On a computer, go to gemini.google.com.
2. Open Settings, then Connected Apps.
3. Under Custom apps, choose Add a custom app.
4. Paste the server address and choose Next.
5. Follow the on-screen steps to sign in.

Then type @ in a chat and pick the app, on the web or in the Gemini mobile app. Google’s help page sets the conditions: you must be 18 or over and in the US, signed in with a personal Google Account rather than a work or school one, with Keep Activity on, using Gemini in English. Custom apps can only be added in the web app.

How do I add an MCP server to Cursor or VS Code?

Cursor. Install and manage servers from the Customize page, or add the server to ~/.cursor/mcp.json to use it in every project:

{
  "mcpServers": {
    "example": { "url": "https://example.com/mcp" }
  }
}

Cursor’s docs say it supports sign-in (OAuth) for remote servers and, by default, asks for approval before it uses an MCP tool.

VS Code. Run MCP: Add Server from the Command Palette, choose HTTP and paste the address, then give the server a name and choose where to save it. VS Code may ask you to trust the server when it first starts (VS Code docs).

How do I add an MCP server to Claude Code or Codex?

Both take one command in your terminal. In Claude Code:

claude mcp add --transport http example https://example.com/mcp

Then type /mcp inside Claude Code and sign in. The server is saved for the current project; add --scope user to use it in all your projects (Claude Code docs).

In Codex:

codex mcp add example --url https://example.com/mcp
codex mcp login example

The second command signs you in, for servers that use OAuth. Codex keeps the server in ~/.codex/config.toml, which the ChatGPT desktop app, the Codex CLI and the IDE extension share (OpenAI’s MCP docs).

Can agents like ChatGPT Dots and Grok Bot use these tools?

Partly. OpenAI says ChatGPT Dots can use the plugins you’ve set up in ChatGPT, so a server added there can reach your agent, though the apps available to it may differ. Grok Bot adds a server when you ask it in chat, according to Cursor’s support team. Meta’s help page describes custom connectors that Muse builds from a service’s API, and doesn’t mention MCP. We compare all three in ChatGPT Dots, Grok Bot and Meta Muse explained.

What if it doesn’t work?

• Check the address. It must be the MCP server address, not the service’s homepage, and reachable over the internet.
• Check your plan and role. On work plans, an admin may have to add or approve the tool.
• Sign in again. Sign-ins can expire; reconnect from the app’s connector settings.
• Ask an admin to refresh it. In ChatGPT Business and Enterprise, a server’s tools are fixed when an admin approves it, so later changes need an admin to refresh them.

Only add servers you trust. For what to check first, see what to ask before you connect an agent.

Where IKAG fits

IKAG is designed to connect exactly this way: one MCP link in apps like these, then a sign-in the first time your AI needs it. How pay per call is meant to work is on the homepage; no prices have been set. IKAG is opening to early users and data partners first.