diff --git a/src/edr_pydantic_classes/collections.py b/src/edr_pydantic_classes/collections.py
new file mode 100644
index 0000000..d78d1e3
--- /dev/null
+++ b/src/edr_pydantic_classes/collections.py
@@ -0,0 +1,43 @@
+from __future__ import annotations
+
+from typing import List
+from typing import Optional
+
+from .data_queries import DataQueries
+from .extent import Extent
+from .link import Link
+from .my_base_model import EDRBaseModel
+from .parameter import ParameterNames
+
+
+# TODO instances or collections as base?
+class Collection(EDRBaseModel):
+    links: List[Link]
+    id: str
+    extent: Extent
+    parameter_names: ParameterNames
+    title: Optional[str] = None
+    description: Optional[str] = None
+    keywords: Optional[List[str]] = None
+    data_queries: Optional[DataQueries] = None
+    # TODO required according to A.13, string array or crs object?
+    crs: Optional[List[str]] = None
+    # TODO in req as f?
+    output_formats: Optional[List[str]] = None
+    # TODO may have distanceunits, if radius is in link, it shall have distanceunits
+    distanceunits: Optional[List[str]] = None
+
+
+class CollectionsModel(EDRBaseModel):
+    links: List[Link]
+    collections: List[Collection]
+
+
+class InstancesModel(EDRBaseModel):
+    links: List[Link]
+    instances: List[Instance]
+
+
+# For now, the instance metadata corresponds to the first collection metadata. So they have equal classes
+class Instance(Collection):
+    pass
diff --git a/src/edr_pydantic_classes/instances.py b/src/edr_pydantic_classes/instances.py
deleted file mode 100644
index 85682b7..0000000
--- a/src/edr_pydantic_classes/instances.py
+++ /dev/null
@@ -1,107 +0,0 @@
-# generated by datamodel-codegen:
-#   filename:  https://schemas.opengis.net/ogcapi/edr/1.0/openapi/schemas/instances.yaml
-#   timestamp: 2022-06-29T09:43:11+00:00
-from __future__ import annotations
-
-from datetime import datetime
-from enum import Enum
-from typing import Dict
-from typing import List
-from typing import Optional
-from typing import Union
-
-from .generic_models import CubeVariables
-from .generic_models import Link
-from .generic_models import Variables
-from .my_base_model import MyBaseModel
-from .parameter import Parameter
-
-
-class CRSOptions(str, Enum):
-    wgs84 = "WGS84"
-
-
-class Spatial(MyBaseModel):
-    bbox: List[List[float]]
-    crs: CRSOptions
-    name: Optional[str] = None
-
-
-class Temporal(MyBaseModel):
-    interval: List[List[datetime]]
-    values: List[str]
-    trs: str
-    name: Optional[str] = None
-
-
-class Vertical(MyBaseModel):
-    interval: List[List[float]]
-    vrs: str
-    name: Optional[str] = None
-
-
-class Extent(MyBaseModel):
-    spatial: Optional[Spatial] = None
-    temporal: Optional[Temporal] = None
-    vertical: Optional[Vertical] = None
-
-
-class DataQueryLink(MyBaseModel):
-    model_config = {
-        "json_schema_extra": {
-            "examples": [
-                {
-                    "href": "https://data.example.com/collections/monitoringsites/locations",
-                    "rel": "alternate",
-                    "hreflang": "en",
-                }
-            ],
-        }
-    }
-    href: str
-    hreflang: Optional[str] = None
-    rel: str
-    variables: Union[Variables, CubeVariables]
-
-
-class DataQuery(MyBaseModel):
-    link: DataQueryLink
-
-
-class DataQueries(MyBaseModel):
-    position: Optional[DataQuery] = None
-    radius: Optional[DataQuery] = None
-    area: Optional[DataQuery] = None
-    cube: Optional[DataQuery] = None
-    trajectory: Optional[DataQuery] = None
-    corridor: Optional[DataQuery] = None
-    locations: Optional[DataQuery] = None
-    items: Optional[DataQuery] = None
-
-
-class Instance(MyBaseModel):
-    links: List[Link]
-    id: str
-    title: Optional[str] = None
-    description: Optional[str] = None
-    keywords: Optional[List[str]] = None
-    extent: Extent
-    data_queries: Optional[DataQueries] = None
-    crs: Optional[List[str]] = None
-    output_formats: Optional[List[str]] = None
-    parameter_names: Optional[Dict[str, Parameter]] = None
-
-
-class InstancesModel(MyBaseModel):
-    links: List[Link]
-    instances: List[Instance]
-
-
-# For now, the collection metadata corresponds to the first instance metadata. So they have equal classes
-class Collection(Instance):
-    pass
-
-
-class CollectionsModel(MyBaseModel):
-    links: List[Link]
-    collections: List[Collection]