Victor Schappert (vcschapp) · Aug 12, 2026 · Aug 4, 2026 · Aug 6, 2026 · Aug 6, 2026 · Aug 12, 2026
diff --git a/packages/overture-schema-codegen/changelog.d/633.misc.md b/packages/overture-schema-codegen/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Updated scaffold test expectations for optional `sources[].dataset`.
diff --git a/packages/overture-schema-codegen/tests/test_pyspark_scaffold.py b/packages/overture-schema-codegen/tests/test_pyspark_scaffold.py
@@ -140,8 +140,9 @@ def test_array_nested_field_builds_path(self, connector_spec: ModelSpec) -> None
         assert isinstance(scaffold["sources"], list)
         assert len(scaffold["sources"]) == 1
         elem = scaffold["sources"][0]
-        # Required sibling 'dataset' populated
-        assert "dataset" in elem
+        # Required sibling 'property' populated; optional 'dataset' omitted
+        assert "property" in elem
+        assert "dataset" not in elem
 
     def test_scaffold_is_dict(self, connector_spec: ModelSpec) -> None:
         field_nodes, _ = build_checks(connector_spec)

diff --git a/packages/overture-schema-common/changelog.d/633.feature.md b/packages/overture-schema-common/changelog.d/633.feature.md
@@ -0,0 +1 @@
+Made `sources[].dataset` optional; sources entries no longer require a `dataset` value.
diff --git a/packages/overture-schema-common/src/overture/schema/common/sources.py b/packages/overture-schema-common/src/overture/schema/common/sources.py
@@ -44,14 +44,17 @@ class SourceItem(BaseModel):
             it applies to the feature geometry.
         """).strip()
     )
-    dataset: str = Field(
-        description=textwrap.dedent("""
-            Name of the dataset where the source data can be found.
-        """).strip()
-    )
 
     # Optional
 
+    dataset: Annotated[
+        str | None,
+        Field(
+            description=textwrap.dedent("""
+                Name of the dataset where the source data can be found.
+            """).strip()
+        ),
+    ] = None
     license: Annotated[
         StrippedString | None,
         Field(

diff --git a/packages/overture-schema-common/tests/test_models.py b/packages/overture-schema-common/tests/test_models.py
@@ -85,7 +85,7 @@ def test_feature_json_schema() -> None:
                     },
                     "confidence": {"maximum": 1.0, "minimum": 0.0, "type": "number"},
                 },
-                "required": ["property", "dataset"],
+                "required": ["property"],
                 "type": "object",
             }
         },

diff --git a/packages/overture-schema-theme-addresses/changelog.d/633.misc.md b/packages/overture-schema-theme-addresses/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-addresses/tests/address_baseline_schema.json b/packages/overture-schema-theme-addresses/tests/address_baseline_schema.json
@@ -88,8 +88,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/changelog.d/633.misc.md b/packages/overture-schema-theme-base/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-base/tests/bathymetry_baseline_schema.json b/packages/overture-schema-theme-base/tests/bathymetry_baseline_schema.json
@@ -109,8 +109,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/tests/infrastructure_baseline_schema.json b/packages/overture-schema-theme-base/tests/infrastructure_baseline_schema.json
@@ -418,8 +418,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/tests/land_baseline_schema.json b/packages/overture-schema-theme-base/tests/land_baseline_schema.json
@@ -291,8 +291,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/tests/land_cover_baseline_schema.json b/packages/overture-schema-theme-base/tests/land_cover_baseline_schema.json
@@ -126,8 +126,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/tests/land_use_baseline_schema.json b/packages/overture-schema-theme-base/tests/land_use_baseline_schema.json
@@ -369,8 +369,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-base/tests/water_baseline_schema.json b/packages/overture-schema-theme-base/tests/water_baseline_schema.json
@@ -222,8 +222,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-buildings/changelog.d/633.misc.md b/packages/overture-schema-theme-buildings/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-buildings/tests/building_baseline_schema.json b/packages/overture-schema-theme-buildings/tests/building_baseline_schema.json
@@ -405,8 +405,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-buildings/tests/building_part_baseline_schema.json b/packages/overture-schema-theme-buildings/tests/building_part_baseline_schema.json
@@ -291,8 +291,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-divisions/changelog.d/633.misc.md b/packages/overture-schema-theme-divisions/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-divisions/tests/division_area_baseline_schema.json b/packages/overture-schema-theme-divisions/tests/division_area_baseline_schema.json
@@ -250,8 +250,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-divisions/tests/division_baseline_schema.json b/packages/overture-schema-theme-divisions/tests/division_baseline_schema.json
@@ -353,8 +353,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-divisions/tests/division_boundary_baseline_schema.json b/packages/overture-schema-theme-divisions/tests/division_boundary_baseline_schema.json
@@ -140,8 +140,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-places/changelog.d/633.misc.md b/packages/overture-schema-theme-places/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-places/tests/place_baseline_schema.json b/packages/overture-schema-theme-places/tests/place_baseline_schema.json
@@ -317,8 +317,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-transportation/changelog.d/633.misc.md b/packages/overture-schema-theme-transportation/changelog.d/633.misc.md
@@ -0,0 +1 @@
+Regenerated baseline schemas for optional `sources[].dataset`.
diff --git a/packages/overture-schema-theme-transportation/tests/connector_baseline_schema.json b/packages/overture-schema-theme-transportation/tests/connector_baseline_schema.json
@@ -73,8 +73,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/packages/overture-schema-theme-transportation/tests/segment_baseline_schema.json b/packages/overture-schema-theme-transportation/tests/segment_baseline_schema.json
@@ -1253,8 +1253,7 @@
         }
       },
       "required": [
-        "property",
-        "dataset"
+        "property"
       ],
       "title": "SourceItem",
       "type": "object"

diff --git a/schema/defs.yaml b/schema/defs.yaml
@@ -269,7 +269,7 @@ description: Common schema definitions shared by all themes
         Additional metadata such as license, record_id, update_time, and
         confidence may also be provided.
       type: object
-      required: [property, dataset]
+      required: [property]
       allOf:
         - { "$ref": "#/$defs/propertyContainers/geometricRangeScopeContainer" }
       unevaluatedProperties: false
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Updated scaffold test expectations for optional `sources[].dataset`.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Made `sources[].dataset` optional; sources entries no longer require a `dataset` value.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Regenerated baseline schemas for optional `sources[].dataset`.