diff --git a/task-sdk/src/airflow/sdk/api/client.py b/task-sdk/src/airflow/sdk/api/client.py
index 0a3de02894150..02886cecc18e6 100644
--- a/task-sdk/src/airflow/sdk/api/client.py
+++ b/task-sdk/src/airflow/sdk/api/client.py
@@ -48,6 +48,7 @@
     ConnectionResponse,
     DagRunStateResponse,
     DagRunType,
+    HITLDetailRequest,
     HITLDetailResponse,
     HITLUser,
     InactiveAssetsResponse,
@@ -77,7 +78,6 @@
     CreateHITLDetailPayload,
     DRCount,
     ErrorResponse,
-    HITLDetailRequestResult,
     OKResponse,
     PreviousDagRunResult,
     SkipDownstreamTasks,
@@ -754,7 +754,7 @@ def add_response(
         multiple: bool = False,
         params: dict[str, Any] | None = None,
         assigned_users: list[HITLUser] | None = None,
-    ) -> HITLDetailRequestResult:
+    ) -> HITLDetailRequest:
         """Add a Human-in-the-loop response that waits for human response for a specific Task Instance."""
         payload = CreateHITLDetailPayload(
             ti_id=ti_id,
@@ -770,7 +770,7 @@ def add_response(
             f"/hitlDetails/{ti_id}",
             content=payload.model_dump_json(),
         )
-        return HITLDetailRequestResult.model_validate_json(resp.read())
+        return HITLDetailRequest.model_validate_json(resp.read())
 
     def update_response(
         self,
diff --git a/task-sdk/src/airflow/sdk/execution_time/comms.py b/task-sdk/src/airflow/sdk/execution_time/comms.py
index 618a29e36ed93..45986bd398fee 100644
--- a/task-sdk/src/airflow/sdk/execution_time/comms.py
+++ b/task-sdk/src/airflow/sdk/execution_time/comms.py
@@ -584,6 +584,17 @@ class HITLDetailRequestResult(HITLDetailRequest):
 
     type: Literal["HITLDetailRequestResult"] = "HITLDetailRequestResult"
 
+    @classmethod
+    def from_api_response(cls, hitl_request: HITLDetailRequest) -> HITLDetailRequestResult:
+        """
+        Get HITLDetailRequestResult from HITLDetailRequest (API response).
+
+        HITLDetailRequest is the API response model. We convert it to HITLDetailRequestResult
+        for communication between the Supervisor and task process, adding the discriminator field
+        required for the tagged union deserialization.
+        """
+        return cls(**hitl_request.model_dump(exclude_defaults=True), type="HITLDetailRequestResult")
+
 
 ToTask = Annotated[
     AssetResult
diff --git a/task-sdk/src/airflow/sdk/execution_time/supervisor.py b/task-sdk/src/airflow/sdk/execution_time/supervisor.py
index 2a20e4eec4e0b..48086a79f2f05 100644
--- a/task-sdk/src/airflow/sdk/execution_time/supervisor.py
+++ b/task-sdk/src/airflow/sdk/execution_time/supervisor.py
@@ -94,6 +94,7 @@
     GetXComCount,
     GetXComSequenceItem,
     GetXComSequenceSlice,
+    HITLDetailRequestResult,
     InactiveAssetsResult,
     MaskSecret,
     PrevSuccessfulDagRunResult,
@@ -1383,7 +1384,7 @@ def _handle_request(self, msg: ToSupervisor, log: FilteringBoundLogger, req_id:
                 # Since we've sent the message, return. Nothing else in this ifelse/switch should return directly
                 return
         elif isinstance(msg, CreateHITLDetailPayload):
-            resp = self.client.hitl.add_response(
+            hitl_detail_request = self.client.hitl.add_response(
                 ti_id=msg.ti_id,
                 options=msg.options,
                 subject=msg.subject,
@@ -1393,7 +1394,8 @@ def _handle_request(self, msg: ToSupervisor, log: FilteringBoundLogger, req_id:
                 multiple=msg.multiple,
                 assigned_users=msg.assigned_users,
             )
-            self.send_msg(resp, request_id=req_id, error=None, **dump_opts)
+            resp = HITLDetailRequestResult.from_api_response(hitl_detail_request)
+            dump_opts = {"exclude_unset": True}
         elif isinstance(msg, MaskSecret):
             mask_secret(msg.value, msg.name)
         else:
diff --git a/task-sdk/tests/task_sdk/api/test_client.py b/task-sdk/tests/task_sdk/api/test_client.py
index ed3997aefc6cc..51a28fcd196a9 100644
--- a/task-sdk/tests/task_sdk/api/test_client.py
+++ b/task-sdk/tests/task_sdk/api/test_client.py
@@ -39,6 +39,7 @@
     ConnectionResponse,
     DagRunState,
     DagRunStateResponse,
+    HITLDetailRequest,
     HITLDetailResponse,
     HITLUser,
     TerminalTIState,
@@ -49,7 +50,6 @@
 from airflow.sdk.execution_time.comms import (
     DeferTask,
     ErrorResponse,
-    HITLDetailRequestResult,
     OKResponse,
     PreviousDagRunResult,
     RescheduleTask,
@@ -1300,7 +1300,7 @@ def handle_request(request: httpx.Request) -> httpx.Response:
             params=None,
             multiple=False,
         )
-        assert isinstance(result, HITLDetailRequestResult)
+        assert isinstance(result, HITLDetailRequest)
         assert result.ti_id == ti_id
         assert result.options == ["Approval", "Reject"]
         assert result.subject == "This is subject"
diff --git a/task-sdk/tests/task_sdk/execution_time/test_supervisor.py b/task-sdk/tests/task_sdk/execution_time/test_supervisor.py
index 4669e2c7ef2d9..8c219a4eebf74 100644
--- a/task-sdk/tests/task_sdk/execution_time/test_supervisor.py
+++ b/task-sdk/tests/task_sdk/execution_time/test_supervisor.py
@@ -2242,9 +2242,7 @@ class RequestTestCase:
             "subject": "This is subject",
             "body": "This is body",
             "defaults": ["Approve"],
-            "multiple": False,
             "params": {},
-            "assigned_users": None,
             "type": "HITLDetailRequestResult",
         },
         client_mock=ClientMock(