MCP Architecture
MCP architecture has a few main parts: the Host, the LLM, the MCP client, the MCP server, and the external system. Together, they help the AI application communicate with business domains and data sources in a standard way.
This is a simplified learning demo. No code or technical details, just the core idea.
Pick a request and watch it travel through the architecture, step by step, and back.
The Host app (where the LLM lives) uses a dedicated MCP client for each server it connects to, one client per server. Think of a server as access to one domain or department, such as Engineering, Customer, or Finance. That server may use several tools behind the scenes, but it presents one domain path to the AI app. Here's one server connection, in detail. Try unchecking it below.
An MCP server usually represents access to one domain or integration, not everything at once. It can expose several related resources within that domain.
Knowledge server → documents, policies, playbooks
Engineering server → code work, issues, release tasks
Operations server → meetings, schedules, reminders
Customer server → accounts, orders, support records
Every request follows this same path, and the answer travels back the same way, no matter which system is involved.
MCP architecture separates the LLM from external domains and systems.
The MCP client belongs on the AI application side.
The MCP server represents access to one domain or integration, which can include several related resources.
A client connects to exactly one server, but the Host app can run many clients at once, giving it access to many servers.
This structure makes connections easier to understand and manage.
MCP architecture gives AI apps a clear path to external domains: the Host uses a dedicated MCP client for each server it needs, and each server connects to its own domain or system.