id property
ID is the work item's opaque handle, and it is NOT how you address it — ProjectKey plus Number is. Its shape says which source answered: a forge issue's is the forge's own numeric id in decimal, an index row's a minted "issue_" id.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? id;