Model for the annotation_metadata table

h/models/__init__.py

@@ -18,6 +18,7 @@
 """
 from h.models.activation import Activation
 from h.models.annotation import Annotation
+from h.models.annotation_metadata import AnnotationMetadata
 from h.models.annotation_moderation import AnnotationModeration
 from h.models.annotation_slim import AnnotationSlim
 from h.models.auth_client import AuthClient

h/models/annotation_metadata.py

@@ -0,0 +1,25 @@
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql as pg
+from sqlalchemy.ext.mutable import MutableDict
+
+from h.db import Base
+
+
+class AnnotationMetadata(Base):
+    __tablename__ = "annotation_metadata"
+
+    annotation_id = sa.Column(
+        sa.Integer,
+        sa.ForeignKey("annotation_slim.id", ondelete="cascade"),
+        nullable=False,
+        unique=True,
+        primary_key=True,
+    )
+    """FK to annotation_slim.id"""
+
+    data = sa.Column(
+        MutableDict.as_mutable(pg.JSONB),
+        default=dict,
+        server_default=sa.func.jsonb("{}"),
+        nullable=True,
+    )