Extension Support Matrix ↗
noOriginal Documentation
Documentation Index#
Fetch the complete documentation index at: https://modelcontextprotocol.io/llms.txt Use this file to discover all available pages before exploring further.
Which MCP clients implement which official extensions
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This matrix shows which MCP clients support each official extension. Extensions are always opt-in — a client only uses an extension if both client and server declare support during the initialization handshake.
This list is maintained by the community. If you notice any inaccuracies or would like to add or update information, please submit a pull request.
Extension overview#
| Extension | Identifier | Description |
|---|---|---|
| MCP Apps | io.modelcontextprotocol/ui | Interactive HTML interfaces rendered inline in the conversation |
| OAuth Client Credentials | io.modelcontextprotocol/oauth-client-credentials | Machine-to-machine auth without interactive user login |
| Enterprise-Managed Authorization | io.modelcontextprotocol/enterprise-managed-authorization | Centralized access control via enterprise IdP |
Support matrix#
| Client | MCP Apps | OAuth Client Credentials | Enterprise Auth |
|---|---|---|---|
| Claude (web) | |||
| Claude Desktop | |||
| VS Code GitHub Copilot | |||
| Goose | |||
| Postman | |||
| MCPJam | |||
| ChatGPT |
Auth extension support (OAuth Client Credentials and Enterprise-Managed Authorization) is tracked separately from the core MCP authorization features (DCR, CIMD) shown on the clients page. Check each extension’s specification and the ext-auth repository for the latest implementation status.
Adding extension support to your client#
If you’re building an MCP client and want to implement extension support:
- Review the extension specification (e.g., in the ext-auth or ext-apps repository)
- Declare support in the
extensionsfield of yourinitializecapabilities - Implement the extension’s protocol requirements
- Submit a pull request to update this matrix
See Extensions Overview for details on the capability negotiation mechanism.