diff --git a/airflow/api_fastapi/execution_api/datamodels/taskinstance.py b/airflow/api_fastapi/execution_api/datamodels/taskinstance.py
index 415cc05abe6f1..c11bf08e17d11 100644
--- a/airflow/api_fastapi/execution_api/datamodels/taskinstance.py
+++ b/airflow/api_fastapi/execution_api/datamodels/taskinstance.py
@@ -34,6 +34,8 @@
 class TIEnterRunningPayload(BaseModel):
     """Schema for updating TaskInstance to 'RUNNING' state with minimal required fields."""
 
+    model_config = ConfigDict(extra="forbid")
+
     state: Annotated[
         Literal[TIState.RUNNING],
         # Specify a default in the schema, but not in code.
@@ -52,6 +54,8 @@ class TIEnterRunningPayload(BaseModel):
 class TITerminalStatePayload(BaseModel):
     """Schema for updating TaskInstance to a terminal state (e.g., SUCCESS or FAILED)."""
 
+    model_config = ConfigDict(extra="forbid")
+
     state: TerminalTIState
 
     end_date: UtcDateTime
@@ -61,12 +65,16 @@ class TITerminalStatePayload(BaseModel):
 class TITargetStatePayload(BaseModel):
     """Schema for updating TaskInstance to a target state, excluding terminal and running states."""
 
+    model_config = ConfigDict(extra="forbid")
+
     state: IntermediateTIState
 
 
 class TIDeferredStatePayload(BaseModel):
     """Schema for updating TaskInstance to a deferred state."""
 
+    model_config = ConfigDict(extra="forbid")
+
     state: Annotated[
         Literal[IntermediateTIState.DEFERRED],
         # Specify a default in the schema, but not in code, so Pydantic marks it as required.
@@ -119,6 +127,8 @@ def ti_state_discriminator(v: dict[str, str] | BaseModel) -> str:
 class TIHeartbeatInfo(BaseModel):
     """Schema for TaskInstance heartbeat endpoint."""
 
+    model_config = ConfigDict(extra="forbid")
+
     hostname: str
     pid: int
 
@@ -158,8 +168,6 @@ class DagRun(BaseModel):
 class TIRunContext(BaseModel):
     """Response schema for TaskInstance run context."""
 
-    model_config = ConfigDict(extra="forbid")
-
     dag_run: DagRun
     """DAG run information for the task instance."""
 
diff --git a/task_sdk/src/airflow/sdk/api/datamodels/_generated.py b/task_sdk/src/airflow/sdk/api/datamodels/_generated.py
index 37062480865a5..38889c5723486 100644
--- a/task_sdk/src/airflow/sdk/api/datamodels/_generated.py
+++ b/task_sdk/src/airflow/sdk/api/datamodels/_generated.py
@@ -74,6 +74,9 @@ class TIDeferredStatePayload(BaseModel):
     Schema for updating TaskInstance to a deferred state.
     """
 
+    model_config = ConfigDict(
+        extra="forbid",
+    )
     state: Annotated[Literal["deferred"] | None, Field(title="State")] = "deferred"
     classpath: Annotated[str, Field(title="Classpath")]
     trigger_kwargs: Annotated[dict[str, Any] | None, Field(title="Trigger Kwargs")] = None
@@ -86,6 +89,9 @@ class TIEnterRunningPayload(BaseModel):
     Schema for updating TaskInstance to 'RUNNING' state with minimal required fields.
     """
 
+    model_config = ConfigDict(
+        extra="forbid",
+    )
     state: Annotated[Literal["running"] | None, Field(title="State")] = "running"
     hostname: Annotated[str, Field(title="Hostname")]
     unixname: Annotated[str, Field(title="Unixname")]
@@ -98,6 +104,9 @@ class TIHeartbeatInfo(BaseModel):
     Schema for TaskInstance heartbeat endpoint.
     """
 
+    model_config = ConfigDict(
+        extra="forbid",
+    )
     hostname: Annotated[str, Field(title="Hostname")]
     pid: Annotated[int, Field(title="Pid")]
 
@@ -107,6 +116,9 @@ class TITargetStatePayload(BaseModel):
     Schema for updating TaskInstance to a target state, excluding terminal and running states.
     """
 
+    model_config = ConfigDict(
+        extra="forbid",
+    )
     state: IntermediateTIState
 
 
@@ -201,9 +213,6 @@ class TIRunContext(BaseModel):
     Response schema for TaskInstance run context.
     """
 
-    model_config = ConfigDict(
-        extra="forbid",
-    )
     dag_run: DagRun
     variables: Annotated[list[VariableResponse] | None, Field(title="Variables")] = None
     connections: Annotated[list[ConnectionResponse] | None, Field(title="Connections")] = None
@@ -214,5 +223,8 @@ class TITerminalStatePayload(BaseModel):
     Schema for updating TaskInstance to a terminal state (e.g., SUCCESS or FAILED).
     """
 
+    model_config = ConfigDict(
+        extra="forbid",
+    )
     state: TerminalTIState
     end_date: Annotated[datetime, Field(title="End Date")]
diff --git a/tests/api_fastapi/execution_api/routes/test_variables.py b/tests/api_fastapi/execution_api/routes/test_variables.py
index 20a9b43c07ace..45868e2a6092e 100644
--- a/tests/api_fastapi/execution_api/routes/test_variables.py
+++ b/tests/api_fastapi/execution_api/routes/test_variables.py
@@ -54,7 +54,7 @@ def test_variable_get_from_db(self, client, session):
         {"AIRFLOW_VAR_KEY1": "VALUE"},
     )
     def test_variable_get_from_env_var(self, client, session):
-        response = client.get("/execution/variables/key1")
+        response = client.get("/execution/variables/key1", params={"foo": "bar"})
 
         assert response.status_code == 200
         assert response.json() == {"key": "key1", "value": "VALUE"}