MCP's real power lies not just in what it defines, but in what it leaves room for. As teams push MCP into production, the need to add custom capabilities streaming responses, domain-specific metadata, proprietary auth flows runs headfirst into the risk of breaking existing clients and servers.
This talk walks through the practical discipline of extending MCP without fracturing compatibility: how to use capability negotiation correctly, where to extend vs. where to fork, how to version custom extensions gracefully, and how to contribute extensions upstream without waiting for a spec cycle.
Real examples from building extensions in the wild what worked, what silently broke things, and what the spec doesn't yet have a good answer for.
Attendees leave with a working mental model for extension design and a checklist for evaluating whether a custom extension is safe to ship