An Id contains the identifiers used to reference this topic (entity) in the Knowledge Graph. The Knowledge Graph supports several forms of identifiers: - "mids" (machine ids) that are assigned at creation time, and support a resolution mechanism that tracks topics after they are merged (for more about mids, see go/kg-mid), - "ids" are human-readable ids (HRIDs) that are derived from a namespace hierarchy stored in Knowledge Graph, and a set of rules, - "guids" are low-level ids historically used in Freebase (pre-Knowledge Graph, deprecated). Only the mid and id are supplied here. Note that mids can be converted to guids or uint64s (see //metaweb/util/mid/mid.h).

Attributes

• id (type: String.t, default: nil) - "id" may be a human readable ID (HRID) or a MID. Originally it was intended to always be a human readable ID, but that convention was not always followed so clients should be wary. Not every topic has an id.
• mid (type: String.t, default: nil) - The "mid" should be used whenever a globally unique, primary key into the Knowledge Graph is needed. These keys are always prefixed with the "/m" and "/g", (and more rarely the "/x" and "/t") namespaces, and are alphanumeric strings consisting of lowercase letters excluding vowels, numbers and the underscore character. (Applications should not assume a constant length for these strings as Livegraph reserves the right to extend the number of characters to accommodate more topics.)