Pharo MCP Server

What is Pharo MCP Server?

Pharo MCP Server is a server-side implementation of Anthropic’s Model Context Protocol (MCP) for the Pharo Smalltalk environment. It enables LLMs like Claude to discover and invoke functionalities within Pharo applications through a standardized protocol.

How to use Pharo MCP Server?

Install the server using Metacello with the provided code, then register Pharo methods or blocks as tools using the built‑in API. The server exposes configurable HTTP endpoints for discovery, description, and invocation.

Key features of Pharo MCP Server

• Implements core MCP endpoints: discovery, service description, and invocation.
• Dynamic registration of Pharo methods or blocks as tools.
• Automatic generation of service‑description JSON from registered tools.
• Built on the Teapot micro web framework and NeoJSON for JSON handling.
• Extensible for integration into larger Pharo applications.
• Planned input validation using JSON Schema and helpers for common object models.

Use cases of Pharo MCP Server

• Expose Pharo database queries as tools that an LLM agent can call.
• Allow an LLM to create or modify objects in a Pharo application.
• Let conversational AI trigger domain‑specific actions inside a Pharo system.