diff --git a/stac_fastapi/api/stac_fastapi/api/models.py b/stac_fastapi/api/stac_fastapi/api/models.py
index 1c2146d..8454bba 100644
--- a/stac_fastapi/api/stac_fastapi/api/models.py
+++ b/stac_fastapi/api/stac_fastapi/api/models.py
@@ -1,6 +1,6 @@
 """Api request/response models."""
 
-from dataclasses import dataclass, make_dataclass
+from dataclasses import dataclass
 from typing import List, Optional, Type, Union
 
 from fastapi import Path, Query
@@ -25,6 +25,39 @@ except ImportError:  # pragma: nocover
     from starlette.responses import JSONResponse
 
 
+def _create_dataclass_with_post_init(model_name, bases):
+    """Create a dataclass that calls __post_init__ from all base classes.
+
+    The standard make_dataclass only calls __post_init__ from the first
+    class in the MRO that defines it. This function ensures all base
+    __post_init__ methods are called.
+    """
+    import types
+
+    # Create the class using types.new_class
+    model_cls = types.new_class(model_name, bases, {}, lambda ns: ns.update({}))
+
+    # Remove __post_init__ if present, so the dataclass decorator doesn't
+    # add its own call, and we can add our own that calls all bases
+    if "_POST_INIT_NAME" in model_cls.__dict__:
+        del model_cls.__dict__["_POST_INIT_NAME"]
+
+    # Apply the dataclass decorator
+    Model = dataclass(model_cls)
+
+    # Add our __post_init__ that calls all base __post_init methods
+    def __post_init__(self):
+        for base in Model.__mro__:
+            if base is Model:
+                continue
+            if "__post_init__" in base.__dict__:
+                base.__post_init__(self)
+
+    Model.__post_init__ = __post_init__
+
+    return Model
+
+
 def create_request_model(
     model_name="SearchGetRequest",
     base_model: Union[Type[BaseModel], APIRequest] = BaseSearchGetRequest,
@@ -47,7 +80,7 @@ def create_request_model(
 
     # Handle GET requests
     if all([issubclass(m, APIRequest) for m in models]):
-        return make_dataclass(model_name, [], bases=tuple(models))
+        return _create_dataclass_with_post_init(model_name, tuple(models))
 
     # Handle POST requests
     elif all([issubclass(m, BaseModel) for m in models]):
@@ -97,7 +130,7 @@ class CollectionUri(APIRequest):
 class ItemUri(APIRequest):
     """Get or delete item."""
 
-    collection_id: Annotated[str, Path(description="Collection ID")]
+    collection_id: Annotated[str, Path(description="Item ID")]
     item_id: Annotated[str, Path(description="Item ID")]