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
• LOINC - Logical Observation Identifiers Names and Codes
• RxNorm - Normalized names for clinical drugs (NIH)
• MeSH - Medical Subject Headings (NLM)

Features

• 27 specialized tools for medical terminology lookup
• Multi-terminology support in a single server
• Cross-terminology mapping and search
• Built-in caching for improved performance
• Rate limiting to respect API limits
• Detailed responses with rich formatting

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

Variable	Required	Description
WHO_CLIENT_ID	Yes*	WHO ICD API Client ID
WHO_CLIENT_SECRET	Yes*	WHO ICD API Client Secret

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

Other APIs (LOINC, RxNorm, MeSH, SNOMED CT) do not require authentication.

Available Tools (27)

ICD-11 Tools (5)

Tool	Description	Example
icd11_search	Search ICD-11 by term	query: "diabetes mellitus"
icd11_lookup	Get entity details by code/URI	code: "5A11"
icd11_hierarchy	Navigate parent/child relationships	code: "5A11"
icd11_chapters	List all ICD-11 chapters	-
icd11_postcoordination	Get postcoordination axes	code: "5A11"

LOINC Tools (4)

Tool	Description	Example
loinc_search	Search lab tests and observations	query: "glucose"
loinc_details	Get full LOINC code details	loinc_num: "2339-0"
loinc_answers	Get answer list for surveys	loinc_num: "44249-1"
loinc_panels	Get panel/form structure	loinc_num: "24331-1"

RxNorm Tools (5)

Tool	Description	Example
rxnorm_search	Search drugs by name	query: "metformin"
rxnorm_concept	Get drug concept details	rxcui: "6809"
rxnorm_ingredients	Get active ingredients	rxcui: "6809"
rxnorm_classes	Get therapeutic classes	rxcui: "6809"
rxnorm_ndc	Map between RxCUI and NDC	rxcui: "6809"

MeSH Tools (4)

Tool	Description	Example
mesh_search	Search MeSH descriptors	query: "hypertension"
mesh_descriptor	Get descriptor details	mesh_id: "D006973"
mesh_tree	Get tree hierarchy location	mesh_id: "D006973"
mesh_qualifiers	Get allowed qualifiers	mesh_id: "D006973"

SNOMED CT Tools (5)

Tool	Description	Example
snomed_search	Search concepts by term	query: "myocardial infarction"
snomed_concept	Get concept details by SCTID	sctid: "22298006"
snomed_hierarchy	Get parent/child concepts	sctid: "22298006"
snomed_descriptions	Get all descriptions	sctid: "22298006"
snomed_ecl	Execute ECL queries	ecl: "<< 73211009"

Crosswalk Tools (4)

Tool	Description	Example
map_icd10_to_icd11	Map ICD-10 to ICD-11	icd10_code: "E11"
map_snomed_to_icd10	SNOMED to ICD-10 guidance	sctid: "73211009"
map_loinc_to_snomed	LOINC to SNOMED guidance	loinc_code: "2339-0"
find_equivalent	Cross-terminology search	term: "diabetes"

Usage Examples

Search for a diagnosis in ICD-11

Use icd11_search with query "type 2 diabetes mellitus"

Look up a lab test in LOINC

Use loinc_details with loinc_num "2339-0" to get glucose test details

Find drug information in RxNorm

Use rxnorm_search with query "metformin" then rxnorm_concept for details

Search across all terminologies

Use find_equivalent with term "diabetes" to search ICD-11, SNOMED, LOINC, RxNorm, and MeSH

Map ICD-10 to ICD-11

Use map_icd10_to_icd11 with icd10_code "E11" to find ICD-11 equivalents

Terminology Licenses

ICD-11 (WHO)

ICD-11 content is provided under the Creative Commons Attribution-NoDerivatives 3.0 IGO license (CC BY-ND 3.0 IGO).

• You must attribute WHO as the source
• You may not create derivative works
• API access requires registration at https://icd.who.int/icdapi

SNOMED CT

SNOMED CT content is for reference purposes only. Production use requires an IHTSDO (SNOMED International) license.

• Member countries have national licenses
• Affiliate licenses available for others
• More info: https://www.snomed.org/snomed-ct/get-snomed

LOINC

LOINC content is provided under the LOINC License.

• Free for most uses
• Attribution required
• Registration recommended

RxNorm

RxNorm is produced by the U.S. National Library of Medicine and is freely available.

• No license required for use
• Attribution appreciated

MeSH

MeSH is produced by the U.S. National Library of Medicine and is freely available.

• No license required for use
• Attribution appreciated

API Rate Limits

This server implements rate limiting to respect API providers:

API	Rate Limit
WHO ICD-11	5 requests/second
NLM (LOINC, MeSH)	10 requests/second
RxNorm	20 requests/second
SNOMED CT (Snowstorm)	10 requests/second

Development

Building from source

git clone https://github.com/SidneyBissoli/medical-terminologies-mcp.git
cd medical-terminologies-mcp
npm install
npm run build

Running locally

npm start

Testing with MCP Inspector

npx @modelcontextprotocol/inspector node dist/index.js

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Author

Sidney Bissoli

• GitHub: @SidneyBissoli

License

This project is licensed under the MIT License - see the LICENSE file for details.

Note: While this software is MIT licensed, the medical terminologies accessed through it have their own licenses (see Terminology Licenses above).

Acknowledgments

• WHO for the ICD-11 API
• Regenstrief Institute for LOINC
• U.S. National Library of Medicine for RxNorm and MeSH
• SNOMED International for SNOMED CT
• Anthropic for the Model Context Protocol

Support

If you encounter any issues or have questions:

• Open an issue on GitHub
• Check existing issues for solutions

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Made with love for the medical informatics community