ProtoStore is a protobuf-first, schema-driven ORM framework. It allows developers to define database models, relationships, and constraints directly in .proto files using custom protobuf options as schema annotations, and generate fully functional ORM implementations from that schema. ProtoStore provides a schema-first modeling experience, enabling a single source of truth for APIs, persistence, and application models. Instead of introducing a new runtime ORM, ProtoStore targets existing ORMs as