Pharo MCP Server

Connect Pharo to Claude, Cursor or any other MCP client and it stops being a tab you switch to. Pharo Smalltalk implementation of Anthropic's Model Context Protocol (MCP) server specification. Enables LLMs like Claude to interact with Pharo applications. The pharo mcp server is what makes that connection.

What the server does

The Model Context Protocol (MCP), developed by Anthropic, is a specification designed to standardize how Large Language Models (LLMs) interact with external tools and services. It defines mechanisms for:

• MCP Specification Compliance: — Implements the core server-side endpoints:
• Discovery (/.well-known/model-context)
• Service Description (/mcp/description - or configurable path)
• Invocation (/mcp/invoke - or configurable path)
• Dynamic Tool Registration: — Provides a simple API to register Pharo methods or blocks as MCP tools
• Automatic Service Description: — Generates the MCP Service Description JSON based on the registered tools and their metadata (name, description, schemas)

Installation

Setup follows the usual MCP pattern — install or clone the server, register it in your client's configuration file, restart the client.

Available tools

The toolset is worth reading before you wire it up, because it tells you what the integration is really for:

• Extensible — ** Designed to be integrated into larger Pharo applications

Worth knowing first

• It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Where it fits

Among the AI and media services options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Pharo's toolset — Extensible — is a fair guide to whether it matches your workflow. It is maintained by paulwilke; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.