The purpose of the present document is the definition of a standard API for Context Information Management (NGSI-LD API) enabling close to real-time (right-time) access to context/digital twin information coming from many different sources (not only IoT data sources). The present document defines how such an API enables applications to perform updates on context, register context providers which can be queried to get updates on context, query information on current and historic context information and subscribe to receive notifications of context changes. The criteria for choice of the API characteristics are based on requirements resulting from the Use Cases ETSI GR CIM 002 [i.1] and other work items ETSI GR CIM 007 [i.2] and ETSI GS CIM 006 [i.8] on security and on the information model. The present document supersedes prior versions, including ETSI GS CIM 004 [i.16].