Medical Terminologies MCP Server

A Model Context Protocol (MCP) server providing unified access to major global medical terminologies:

• ICD-11 - International Classification of Diseases (WHO)
• SNOMED CT - Systematized Nomenclature of Medicine (opt-in; requires self-hosted Snowstorm)
• LOINC - Logical Observation Identifiers Names and Codes
• RxNorm - Normalized names for clinical drugs (NIH)
• MeSH - Medical Subject Headings (NLM)
• ATC - Anatomical Therapeutic Chemical classification (WHO Collaborating Centre, served via NLM RxClass)
• CID-10 - Brazilian Portuguese translation of ICD-10 (DataSUS V2008, bundled)

🇧🇷 Leia em Português

See it in action

Ask your assistant:

• "What's the ICD-11 code for type 2 diabetes?" → icd11_search
• "Map ICD-10 code E11 to ICD-11." → map_icd10_to_icd11
• "What does LOINC 2339-0 measure?" → loinc_details
• "Qual o código CID-10 para infarto agudo do miocárdio?" → cid10_search

The answers come from authoritative sources (WHO, NLM, NIH, DataSUS) — real codes and mappings, not guesses from training data.

Features

• 33 default tools (39 with SNOMED enabled): 31 terminology tools plus search/fetch for ChatGPT Deep Research
• 3 MCP Prompts that orchestrate tool calls into named workflows (find-medical-code, drug-info, cid10-portuguese-lookup) — clients render these as one-click user actions
• 4 MCP Resources for in-process reference content (info://server, info://cid10/chapters, info://licenses, info://stats) — sub-millisecond reads (except info://stats which round-trips to the StatsCounter Durable Object on the hosted endpoint)
• Multi-terminology support in a single server
• Cross-terminology mapping and search
• Provenance on every response (since v1.8.0): each successful tool result carries a machine-readable provenance block — source, canonical URL, data vintage, real extraction instant (cache hits keep the original fetch instant), ready-to-use citation, and license — in structuredContent.provenance + attribution, mirrored in _meta under com.sidneybissoli.medical/*, with a compact text footer for text-only clients. Multi-source responses (find_equivalent, validate_codes) carry one block per source; server-computed ranking fields are flagged as derived
• Built-in caching for improved performance
• Rate limiting to respect API limits
• Detailed responses with rich formatting
• Two transports: stdio (default; for Claude Desktop, IDE clients) and Streamable HTTP (the hosted Cloudflare Worker at https://medical.sidneybissoli.com/mcp, or your own instance of worker/)

📖 Article (in Portuguese): CID-10, CID-11 e o que muda para quem trabalha com dados do SUS — the V2008 structure in numbers, what the WHO transition tables are and are not, and the licences that differ between sources. Also published on the site, in Portuguese and English: sidneybissoli.com.

Who is this for?

This server is not a clinical-care decision tool — practicing clinicians have specialized assistants (UpToDate AI, OpenEvidence, EHR-integrated tools) for that. The actual audience is researchers, public-health analysts, clinical informatics developers, and educators who need programmatic access to authoritative terminology data.

Try the hosted instance (no install)

A public Cloudflare Workers deployment runs at:

https://medical.sidneybissoli.com/mcp

Connect via the MCP Inspector or any Streamable HTTP MCP client:

npx @modelcontextprotocol/inspector --transport streamable-http \
  --server-url https://medical.sidneybissoli.com/mcp

Or install via Smithery, which proxies the same endpoint through their gateway:

npx -y smithery mcp add sidneybissoli/medical-terminologies-mcp

The hosted instance has WHO credentials configured, so all 33 default tools work without any setup on your side. For your own deployment (e.g. corporate network, different region, custom WHO credentials), see the Installation and Hosted on Cloudflare Workers sections below.

Installation

Global Installation (Recommended)

npm install -g medical-terminologies-mcp

Local Installation

npm install medical-terminologies-mcp

Configuration

Claude Desktop

Add to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "medical-terminologies": {
      "command": "npx",
      "args": ["-y", "medical-terminologies-mcp"],
      "env": {
        "WHO_CLIENT_ID": "your-who-client-id",
        "WHO_CLIENT_SECRET": "your-who-client-secret"
      }
    }
  }
}

Environment Variables

¹ Required for ICD-11 tools. Get credentials at: https://icd.who.int/icdapi.

² See SNOMED CT setup (advanced) below. LOINC, RxNorm, and MeSH need no configuration.

HTTP transport (hosted)

The server runs over stdio by default — that's what Claude Desktop and IDE clients expect. The Streamable HTTP transport is served by the Cloudflare Worker in worker/ (an instance of the maintainer's Fase 0 hosting template). The --http flag of the Node entry was removed in v1.6.0 — if you need a local HTTP endpoint, run the Worker locally:

npm ci && cd worker && npm ci
npm run dev     # wrangler dev on http://localhost:8787
# Inspector via HTTP
npx @modelcontextprotocol/inspector --transport streamable-http --server-url http://localhost:8787/mcp

Hosted endpoints (production and local alike):