Module handler 

MCP request handler implementation

Provides MCP protocol request handling logic, including tool listing, tool invocation, and resource lists.

Main Structs

• HandlerCore: Shared core handling logic (internal use)
• CratesDocsHandler: Standard MCP handler
• CratesDocsHandlerCore: Core handler (provides more fine-grained control)

Design Pattern

Uses composition pattern to eliminate code duplication:

• HandlerCore encapsulates all shared handling logic
• CratesDocsHandler and CratesDocsHandlerCore delegate to HandlerCore
• Supports config merging and optional metrics integration

Structs

CratesDocsHandler

MCP server handler

CratesDocsHandlerCore

Core handler implementation (provides more control)

HandlerConfig

Handler configuration (supports merging)

HandlerCore

Shared core handling logic

ToolExecutionResult

Tool execution result (supports different return type conversions)