The engine's persisted data-model version — the provenance half of
the model stamp, written as modelVersion on every engine-owned
document at its construction and persist choke-points. Conforms-to
semantics: the stamp means "this document conforms to model N now" —
instances are re-stamped on every full persist, so mixed-version fleets
honestly record whichever engine last shaped a doc.
A number is assigned per release, not per change: a declared shape change
merged before this model has shipped joins it, and one merged after it has
shipped moves the number on. Bumping does NOT by itself lock out older
engines — that is the document's derived minReaderModel floor. Declare
every change in DATAMODEL.md; the model-surface snapshot test fails on
undeclared drift.
The engine's persisted data-model version — the provenance half of the model stamp, written as
modelVersionon every engine-owned document at its construction and persist choke-points. Conforms-to semantics: the stamp means "this document conforms to model N now" — instances are re-stamped on every full persist, so mixed-version fleets honestly record whichever engine last shaped a doc.A number is assigned per release, not per change: a declared shape change merged before this model has shipped joins it, and one merged after it has shipped moves the number on. Bumping does NOT by itself lock out older engines — that is the document's derived
minReaderModelfloor. Declare every change inDATAMODEL.md; the model-surface snapshot test fails on undeclared drift.