MCP

What is MCP?

Model Context Protocol (MCP) is an open standard that lets LLMs interact with external tools and data through a structured interface. An MCP server exposes tools: named, schema-validated operations (e.g. “search the model database”, “validate a NeuroML file”, “run code”). A tool call is what happens when the model decides to use one of those tools: the client asks the server to list its tools (tools/list), the model picks the right one and supplies arguments, the client invokes it (tools/call), and the tool result is returned to the model as context for the next step.

How Klea uses it

Klea acts as an MCP client. It configures MCP servers per domain, filters their tools by tag, and enforces tool access levels; it also ships a bundled tools server and the NeuroML-specific nml-mcp server. See MCP servers for how Klea configures and uses MCP servers and how to write tools for Klea.