Medical Terminologies MCP

Unified MCP server giving LLMs and AI agents reliable lookup access to seven medical terminology systems — instead of inventing codes, the model queries the same APIs that WHO, NLM, and NIH publish for clinical and research use.

**Terminologies covered:**

- **ICD-11** — WHO's current International Classification of Diseases
- **LOINC** — laboratory observations and clinical measurements (NLM)
- **RxNorm** — normalized drug nomenclature (NIH)
- **MeSH** — Medical Subject Headings for PubMed search refinement (NLM)
- **ATC** — Anatomical Therapeutic Chemical classification (via NLM RxClass)
- **CID-10** — Brazilian Portuguese ICD-10 (bundled DataSUS V2008)
- **SNOMED CT** — optional, license-gated (requires a self-hosted Snowstorm endpoint)

**Highlights:**

- **37 tools** across search, lookup, hierarchy navigation, batch validation, and cross-terminology mapping
- **Authoritative WHO ICD-10 → ICD-11 mapping** via bundled transition tables (release 2025-01, 11,243 categories — 1,461 with documented alternatives)
- **Cross-terminology batch validator** flags codes that no longer exist and surfaces ICD-10 → ICD-11 replacements
- Tool responses include both human-readable text and `structuredContent` matching a published `outputSchema` (for tools whose results are structured)
- Per-tool `language` parameter on SNOMED, ICD-11, and MeSH for multilingual workflows
- **Hosted Streamable HTTP endpoint** at `medical-terminologies-mcp.sidneybissoli.workers.dev/mcp` —
no install required
- TypeScript / Node 20+, OAuth2 with proper `expires_in` handling, token-bucket rate limiting (5/10/20 req/s per API), exponential backoff with jitter, 313 unit + contract tests gating CI, daily live-API integration cron
- **MIT licensed**

**Audience:** clinical informaticians, biomedical researchers, public-health analysts, EMR integrators, and developers building agentic workflows around medical coding. This is a lookup layer, not a clinical decision tool.