The Pharos MCP Server is an unofficial Model Context Protocol (MCP) implementation for the Pharos database developed by NCATS. It serves as a translation layer that lets AI assistants query Pharos data via a dedicated endpoint, returning results in a usable format. Built with TypeScript for deployment on Cloudflare Workers, the server exposes an SSE endpoint at /sse and is designed to be integrated with AI tools and assistants. The core logic is in src/index.ts, which defines a tool named pharos_graphql_query that accepts a GraphQL query and optional variables, executes it against Pharos' GraphQL API at https://pharos-api.ncats.io/graphql, and returns the results. Capabilities include querying targets (proteins) by UniProt IDs, diseases by name, and ligands by identifiers such as ChEMBL IDs, as well as performing GraphQL introspection to understand the API schema. The README also provides connection guidance for Claude Desktop, example queries, and notes on deployment and customization of the GraphQL queries and server behavior.