MCP client / MCP host

What is an MCP client?

An MCP client is the application on the other side of the connection — the chat assistant, IDE, or terminal agent that speaks the Model Context Protocol and calls a server's tools on your behalf. The detail that surprises people is that MCP support lives in the client, not in the model. That is why an open-weight model running inside an MCP-capable harness gets custom connectors for free, and why swapping models inside the same client changes nothing about your connections.