xAPI is a uniform way of storing and retrieving learner experiences in eLearning systems. This specification is useful for allowing systems to share information for learning analytics or a variety of other purposes. In its simplest form, an xAPI statement is much like a sentence in any written language.

LilxAPI is a simpler, flat version of an xAPI statement. Each statement is required to have only three properties: actor, verb, and object. Each property is limited to a single value. Statements may be represented either as a JSON object with name-value pairs or as an array of values.