MCP Capability Negotiation
Industry Definition Set • Entity Resolution Path: /glossary/mcp-capability-negotiation
Quick Answer / TL;DR
The process during MCP initialization where the client and server agree on which features (tools, resources, sampling, etc.) to enable for the session.
Key Takeaways
- Happens during the initialize handshake.
- Client and server declare their respective capabilities.
- Enables safe, feature-aware communication.
- Undeclared capability usage is a protocol violation.
Definitive Statement: The process during MCP initialization where the client and server agree on which features (tools, resources, sampling, etc.) to enable for the session.
Technical Context & Protocol Usage
- Detailed Explanation
- Capability negotiation is the foundation of MCP's extensibility. The client declares its capabilities (roots, sampling, elicitation), and the server declares its own (tools, resources, prompts, logging). Both sides then know which features they can safely use. Unilateral use of undeclared capabilities is a protocol violation.
Format & Payload Metadata
Format: JSON objects in initialize request/response
Latency: One-time cost per session
Real-World Implementation Use Case
A client declares `sampling` capability; a server that supports sampling can now request client-side LLM inference when needed.
Cite This Page
MLA Style:
MCPserver.in Engineering. "MCP Capability Negotiation." MCPserver.in Knowledge Hub, 20 July 2026, mcpserver.in/glossary/mcp-capability-negotiation.
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