MCP

Note: The MCP integration API may shift as the Model Context Protocol specification evolves. This page provides a summary of the current design. See the skg-mcp crate for the latest API.

Overview

skg-mcp provides a client for the Model Context Protocol (MCP). MCP is an open protocol for connecting AI models to external data sources and tools. The skelegent MCP client connects to MCP servers and exposes their tools as ToolDyn implementations that can be registered in a ToolRegistry.

This means tools hosted on MCP servers can be used by skelegent operators alongside locally defined tools, with no difference in how the operator interacts with them.

Integration pattern

The typical flow is:

1. Connect to one or more MCP servers.
2. Discover available tools from each server.
3. Wrap each MCP tool as an Arc<dyn ToolDyn>.
4. Register them in the operator’s ToolRegistry.

The operator’s ReAct loop then calls MCP tools the same way it calls local tools – through the ToolDyn interface.

When to use MCP

MCP is useful when:

• You want to expose tools from existing MCP-compatible servers (database access, file systems, APIs).
• You want to share tool definitions across multiple applications.
• You want to decouple tool implementation from operator configuration.

For tools that are specific to your application and do not need to be shared, implementing ToolDyn directly is simpler.

Crate

The skg-mcp crate depends on layer0 and skg-tool. Enable it via the mcp feature flag on the skelegent umbrella crate:

[dependencies]
skelegent = { version = "0.4", features = ["mcp"] }