Designed to provide long-term stability for developers, the Wikimedia API is versioned using a version number in the API path (for example: /v1/) that is applied per API namespace. Visit the changelog for the latest version of each namespace.

Following the principles of semantic versioning, the version number is incremented when an endpoint in the namespace is changed in a backwards-incompatible way, such as removing a response property or adding a required parameter. Within a major version, the API may change in backwards-compatible ways, such as adding a response property or optional request parameter.