# Tasks moves to a new Tasks and Events working group

> Source: <https://modelcontextprotocol.io/extensions/client-matrix>
> Published: 2026-10-26 00:00:00+00:00

[official extension](https://modelcontextprotocol.io/extensions/overview). Extensions are always opt-in: a client only uses an extension if both client and server declare support in the

`extensions` field of their [capabilities](https://modelcontextprotocol.io/extensions/overview#negotiation).

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](https://github.com/modelcontextprotocol/modelcontextprotocol/pulls).
## Extension overview

## Support matrix

Auth extension support (OAuth Client Credentials and Enterprise-Managed Authorization) is tracked separately from the core MCP authorization features (DCR, CIMD). Check each extension’s specification and the 

[ext-auth repository](https://github.com/modelcontextprotocol/ext-auth)for the latest implementation status.
## Adding extension support to your client

If you’re building an MCP client and want to implement extension support:
1. Review the extension specification (e.g., in the [ext-auth](https://github.com/modelcontextprotocol/ext-auth) or[ext-apps](https://github.com/modelcontextprotocol/ext-apps) repository)
2. Declare support in the `extensions` field of the`io.modelcontextprotocol/clientCapabilities` your client sends in each request’s`_meta` , and read the server’s`extensions` from its[`server/discover`](https://modelcontextprotocol.io/specification/draft/server/discover) response
3. Implement the extension’s protocol requirements
4. Submit a pull request to update this matrix

[Extensions Overview](https://modelcontextprotocol.io/extensions/overview#negotiation)for details on the capability negotiation mechanism.