Initialize includes client capabilities. Server replies with overlap.

What you're seeing

Capabilities negotiated at initialize: tools, prompts, resources, sampling, logging, completions. Client says what it supports; server says what it implements. Intersection is what they use.

Enables protocol evolution: new features added without breaking older clients/servers.

★ KEY TAKEAWAY
Client and server intersect their capabilities at initialize. Each can implement only some features.
▶ WHAT TO TRY
  • Click through the 3 negotiation steps.
  • Final state: only capabilities BOTH sides have can be used in the session.
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