dbt-core 1.5 ships model contracts, groups, and access controls

The release notes for dbt-core 1.5.0 document breaking changes and a large feature set. Notable additions include enforcing contracts on table, view, and incremental materializations; parsing group resources and group config; an access attribute on nodes; disallowing refs to private models across groups; and native data type and not-null constraints on SQL table materializations.

Data and analytics teams gain machine-checkable shape guarantees and clearer ownership boundaries inside a single DAG. Contracts and constraints make column types and nullability part of the build, while groups and access limit who can depend on private models. Logging, selectors, and optional project version changes affect how projects are operated day to day.

Contracts, groups, and access turn local transformation code into shared, governed interfaces: meaning is declared on models, ownership is named on groups, and cross-team reuse is constrained to what producers mark public.