1. What is MCP?2. Core Architecture3. Host vs Client vs Server
Host vs Client vs Server
📚 Foundation⏱ 6 min⭐ 50 XP
Distinguishing the Roles
Understanding the difference between the Host, Client, and Server is critical when debugging MCP setups.
Component
Role
Examples
Host
User interface and LLM communication. Manages multiple clients.
Claude Desktop, VS Code, Cursor
Client
Protocol-level state machine. Sends requests, parses responses.
@modelcontextprotocol/sdk/client
Server
Executes code, talks to databases/APIs, provides data.
mcp-server-postgres, mcp-github
💡 Key Insight: There is a strict 1-to-1 relationship between an MCP Client instance and an MCP Server. The Host application usually runs many Client instances to talk to multiple Servers simultaneously.
🧪 Knowledge Check
Press 1-4 to select1 of 3
What is the relationship between MCP Clients and MCP Servers?
Many-to-Many
One-to-Many (One client, many servers)
One-to-One
Many-to-One
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Host vs Client vs Server | Foundation — MCP Academy