TypGUID

TypGUID (short for "Type GUID") is an informal term used to describe a globally unique identifier (GUID) assigned to a software type, component, interface or type library. The identifier follows the standard GUID format — a 128-bit value typically shown as a string of hexadecimal digits in five groups enclosed in braces — and serves to uniquely name a type across systems and development teams.

In component-based platforms such as Microsoft COM, separate GUIDs are used to identify classes (CLSIDs), interfaces (IIDs) and type libraries (LIBIDs). The label TypGUID is often used loosely to refer to any GUID whose primary role is identifying a type or type definition rather than an instance. These identifiers enable binary compatibility, registration in system registries, and unambiguous referencing in interop scenarios and plug-in architectures.

Typical practices for TypGUIDs include generating them with system tools (for example, uuidgen, guidgen, or platform APIs like CoCreateGuid), embedding them in metadata or IDL/type library attributes, and documenting them to maintain compatibility. Because GUIDs are designed to be globally unique, collisions are extremely unlikely, but developers are advised to treat TypGUIDs as persistent identifiers: once published for a public interface or library they should not be changed or reused. Proper versioning and compatibility policies help avoid breaking consumers that rely on a given TypGUID.