MCP Core Library

What is MCP Core Library?

MCP Core Library is a crate containing the domain business logic and ports of an MCP server, following a hexagonal architecture. It defines pure business logic and interfaces (ports) while remaining independent of implementation details and specific technologies.

How to use MCP Core Library?

The README does not include installation or configuration instructions. It describes the crate’s architectural role and components; usage details would be provided in the crate’s own documentation.

Key features of MCP Core Library

• Contains only domain business logic and ports.
• Defines a Tool port for executable tools.
• Defines a Transport port for network communication.
• Includes abstract message types and domain errors.
• Uses ToolRegistry for registering and searching tools.
• Minimal dependencies: serde and tokio only.

Use cases of MCP Core Library

• Building an MCP server with clean hexagonal architecture.
• Decoupling domain logic from implementation details like JSON-RPC.
• Managing tool registration and execution via ToolRegistry.

FAQ from MCP Core Library

What is the purpose of the MCP Core Library?

It holds the domain business logic and ports of an MCP server, following hexagonal architecture to keep domain independent of technology.

What dependencies does it require?

Only basic crates: serde and tokio (for async types), to remain minimal and preserve domain isolation.

Does it handle serialization protocols like JSON-RPC?

No, specific protocol details like JSON-RPC are deliberately excluded and will be implemented in external adapters, in accordance with hexagonal architecture principles.

How are tools managed in the library?

The ToolRegistry provides registration and search of tools by name. A simple internal implementation uses a HashMap<String, Box<dyn Tool>>, but could be formalized as a trait for different storage strategies.

What are the main ports defined?

Primary/driving ports: Tool (interface for executable tools). Secondary/driven ports: Transport (interface for network communication).