Systems and data: the ICD-API in one page
Terminologies & Code Systemsarticle · 2 min · updated Oct 14, 2026

Systems and data: the ICD-API in one page

By Rajendra Sharma, RN, CPC, CPBReviewed by Rajendra Sharma, RN, CPC, CPB · Oct 14, 2026

Systems and data: Systems and data: the ICD-API in one page.

ICD-11

The ICD-API in one page

How do you reach ICD-11 from your own software? Here is the ICD-API in one page.

Register, then authenticate

You register on the ICD-API site and view your API access key. That gives you a client ID and secret. The APIs use OAuth 2 client credentials.

  • Step 1 · Registration · Free account. Register on the ICD-API site and view your API access key.
  • Step 2 · Credentials · Two items. You receive a client ID and a client secret.
  • Step 3 · Method · OAuth 2. The APIs use OAuth 2 client credentials.

Token, then entity

Get a token from the token endpoint. Send the API-Version header, version two, with every request. Entity URIs on id dot who dot int are themselves the endpoints, and the linearization endpoints use the name mms for the mortality and morbidity list.

  • Step 1 · Token · Endpoint. Obtain a token from the WHO access management token endpoint.
  • Step 2 · Header · API-Version. Every request needs the API-Version header, version 2.
  • Step 3 · Entities · URI. Entity URIs on id.who.int are themselves the endpoints.

Cloud, or your own servers

The API is hosted in WHO's cloud, but it can also be deployed locally, as Docker containers, Windows services or systemd services on Linux.

Check yourself

Pause and think. Which header should be sent with every ICD-API request? The answer: The API-Version header, set to version two. Send the API-Version header, version two, with every request.

  • A language header only
  • A header carrying the cluster string
  • The API-Version header, set to version two
  • No header is needed

Keep these in mind

Register for a client ID and secret. Use OAuth 2 client credentials, and call with API version two. And choose cloud or local deployment.

  • Register for a client ID and secret
  • OAuth 2 client credentials, then call with API-Version 2
  • Cloud or local deployment

References

  1. WHO ICD-11 Reference Guide

Related entries

SNOMED CT®, LOINC®, ICD and other terminologies are the property of their respective owners and are shown for education under their licences. Licences & attributions