feat(adk): support task_id on span creation

src/agentex/lib/adk/_modules/tracing.py

@@ -64,9 +64,7 @@ def _tracing_service(self) -> TracingService:
         # Re-create the underlying httpx client when the event loop changes
         # (e.g. between HTTP requests in a sync ASGI server) to avoid
         # "Event loop is closed" / "bound to a different event loop" errors.
-        if self._tracing_service_lazy is None or (
-            loop_id is not None and loop_id != self._bound_loop_id
-        ):
+        if self._tracing_service_lazy is None or (loop_id is not None and loop_id != self._bound_loop_id):
             import httpx
 
             # Disable keepalive so each span HTTP call gets a fresh TCP
@@ -93,6 +91,7 @@ async def span(
         input: list[Any] | dict[str, Any] | BaseModel | None = None,
         data: list[Any] | dict[str, Any] | BaseModel | None = None,
         parent_id: str | None = None,
+        task_id: str | None = None,
         start_to_close_timeout: timedelta = timedelta(seconds=5),
         heartbeat_timeout: timedelta = timedelta(seconds=5),
         retry_policy: RetryPolicy = DEFAULT_RETRY_POLICY,
@@ -109,6 +108,7 @@ async def span(
             input (Union[List, Dict, BaseModel]): The input for the span.
             parent_id (Optional[str]): The parent span ID for the span.
             data (Optional[Union[List, Dict, BaseModel]]): The data for the span.
+            task_id (Optional[str]): The task ID this span belongs to.
             start_to_close_timeout (timedelta): The start to close timeout for the span.
             heartbeat_timeout (timedelta): The heartbeat timeout for the span.
             retry_policy (RetryPolicy): The retry policy for the span.
@@ -126,6 +126,7 @@ async def span(
             input=input,
             parent_id=parent_id,
             data=data,
+            task_id=task_id,
             start_to_close_timeout=start_to_close_timeout,
             heartbeat_timeout=heartbeat_timeout,
             retry_policy=retry_policy,
@@ -149,6 +150,7 @@ async def start_span(
         input: list[Any] | dict[str, Any] | BaseModel | None = None,
         parent_id: str | None = None,
         data: list[Any] | dict[str, Any] | BaseModel | None = None,
+        task_id: str | None = None,
         start_to_close_timeout: timedelta = timedelta(seconds=5),
         heartbeat_timeout: timedelta = timedelta(seconds=1),
         retry_policy: RetryPolicy = DEFAULT_RETRY_POLICY,
@@ -162,6 +164,7 @@ async def start_span(
             input (Union[List, Dict, BaseModel]): The input for the span.
             parent_id (Optional[str]): The parent span ID for the span.
             data (Optional[Union[List, Dict, BaseModel]]): The data for the span.
+            task_id (Optional[str]): The task ID this span belongs to.
             start_to_close_timeout (timedelta): The start to close timeout for the span.
             heartbeat_timeout (timedelta): The heartbeat timeout for the span.
             retry_policy (RetryPolicy): The retry policy for the span.
@@ -175,6 +178,7 @@ async def start_span(
             name=name,
             input=input,
             data=data,
+            task_id=task_id,
         )
         if in_temporal_workflow():
             return await ActivityHelpers.execute_activity(
@@ -192,6 +196,7 @@ async def start_span(
                 input=input,
                 parent_id=parent_id,
                 data=data,
+                task_id=task_id,
             )
 
     async def end_span(

src/agentex/lib/core/services/adk/tracing.py

@@ -22,13 +22,15 @@ async def start_span(
         parent_id: str | None = None,
         input: list[Any] | dict[str, Any] | BaseModel | None = None,
         data: list[Any] | dict[str, Any] | BaseModel | None = None,
+        task_id: str | None = None,
     ) -> Span | None:
         trace = self._tracer.trace(trace_id)
         span = await trace.start_span(
             name=name,
             parent_id=parent_id,
             input=input or {},
             data=data,
+            task_id=task_id,
         )
         heartbeat_if_in_workflow("start span")
         return span

src/agentex/lib/core/temporal/activities/adk/tracing_activities.py

@@ -24,6 +24,7 @@ class StartSpanParams(BaseModel):
     name: str
     input: list[Any] | dict[str, Any] | BaseModel | None = None
     data: list[Any] | dict[str, Any] | BaseModel | None = None
+    task_id: str | None = None
 
 
 class EndSpanParams(BaseModel):
@@ -47,6 +48,7 @@ async def start_span(self, params: StartSpanParams) -> Span | None:
             name=params.name,
             input=params.input,
             data=params.data,
+            task_id=params.task_id,
         )
 
     @activity.defn(name=TracingActivityName.END_SPAN)

src/agentex/lib/core/tracing/trace.py

@@ -54,6 +54,7 @@ def start_span(
         parent_id: str | None = None,
         input: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
         data: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
+        task_id: str | None = None,
     ) -> Span:
         """
         Start a new span and register it with the API.
@@ -63,6 +64,7 @@ def start_span(
             parent_id: Optional parent span ID.
             input: Optional input data for the span.
             data: Optional additional data for the span.
+            task_id: Optional ID of the task this span belongs to.
 
         Returns:
             The newly created span.
@@ -86,6 +88,7 @@ def start_span(
             start_time=start_time,
             input=serialized_input,
             data=serialized_data,
+            task_id=task_id,
         )
 
         for processor in self.processors:
@@ -150,6 +153,7 @@ def span(
         parent_id: str | None = None,
         input: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
         data: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
+        task_id: str | None = None,
     ):
         """
         Context manager for spans.
@@ -158,7 +162,7 @@ def span(
         if not self.trace_id:
             yield None
             return
-        span = self.start_span(name, parent_id, input, data)
+        span = self.start_span(name, parent_id, input, data, task_id=task_id)
         try:
             yield span
         finally:
@@ -198,6 +202,7 @@ async def start_span(
         parent_id: str | None = None,
         input: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
         data: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
+        task_id: str | None = None,
     ) -> Span:
         """
         Start a new span and register it with the API.
@@ -207,6 +212,7 @@ async def start_span(
             parent_id: Optional parent span ID.
             input: Optional input data for the span.
             data: Optional additional data for the span.
+            task_id: Optional ID of the task this span belongs to.
 
         Returns:
             The newly created span.
@@ -229,6 +235,7 @@ async def start_span(
             start_time=start_time,
             input=serialized_input,
             data=serialized_data,
+            task_id=task_id,
         )
 
         if self.processors:
@@ -293,6 +300,7 @@ async def span(
         parent_id: str | None = None,
         input: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
         data: dict[str, Any] | list[dict[str, Any]] | BaseModel | None = None,
+        task_id: str | None = None,
     ) -> AsyncGenerator[Span | None, None]:
         """
         Context manager for spans.
@@ -302,14 +310,15 @@ async def span(
             parent_id: Optional parent span ID.
             input: Optional input data for the span.
             data: Optional additional data for the span.
+            task_id: Optional ID of the task this span belongs to.
 
         Yields:
             The span object.
         """
         if not self.trace_id:
             yield None
             return
-        span = await self.start_span(name, parent_id, input, data)
+        span = await self.start_span(name, parent_id, input, data, task_id=task_id)
         try:
             yield span
         finally:

tests/lib/adk/test_tracing_activities.py

@@ -0,0 +1,96 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from unittest.mock import AsyncMock
+
+from temporalio.testing import ActivityEnvironment
+
+from agentex.types.span import Span
+
+
+def _make_span(**overrides) -> Span:
+    defaults = {
+        "id": "span-123",
+        "name": "test-span",
+        "start_time": datetime(2026, 1, 1, tzinfo=timezone.utc),
+        "trace_id": "trace-123",
+    }
+    defaults.update(overrides)
+    return Span(**defaults)
+
+
+def _make_tracing_activities():
+    from agentex.lib.core.services.adk.tracing import TracingService
+    from agentex.lib.core.temporal.activities.adk.tracing_activities import TracingActivities
+
+    mock_service = AsyncMock(spec=TracingService)
+    activities = TracingActivities(tracing_service=mock_service)
+    env = ActivityEnvironment()
+    return mock_service, activities, env
+
+
+class TestStartSpanActivity:
+    async def test_start_span_with_task_id(self):
+        from agentex.lib.core.temporal.activities.adk.tracing_activities import StartSpanParams
+
+        mock_service, activities, env = _make_tracing_activities()
+        expected = _make_span(task_id="task-abc")
+        mock_service.start_span.return_value = expected
+
+        params = StartSpanParams(
+            trace_id="trace-123",
+            name="test-span",
+            task_id="task-abc",
+        )
+        result = await env.run(activities.start_span, params)
+
+        assert result == expected
+        assert result.task_id == "task-abc"
+        mock_service.start_span.assert_called_once_with(
+            trace_id="trace-123",
+            parent_id=None,
+            name="test-span",
+            input=None,
+            data=None,
+            task_id="task-abc",
+        )
+
+    async def test_start_span_without_task_id(self):
+        from agentex.lib.core.temporal.activities.adk.tracing_activities import StartSpanParams
+
+        mock_service, activities, env = _make_tracing_activities()
+        expected = _make_span()
+        mock_service.start_span.return_value = expected
+
+        params = StartSpanParams(trace_id="trace-123", name="test-span")
+        result = await env.run(activities.start_span, params)
+
+        assert result == expected
+        mock_service.start_span.assert_called_once_with(
+            trace_id="trace-123",
+            parent_id=None,
+            name="test-span",
+            input=None,
+            data=None,
+            task_id=None,
+        )
+
+
+class TestEndSpanActivity:
+    async def test_end_span_preserves_task_id(self):
+        from agentex.lib.core.temporal.activities.adk.tracing_activities import EndSpanParams
+
+        mock_service, activities, env = _make_tracing_activities()
+        span = _make_span(task_id="task-abc")
+        expected = _make_span(
+            task_id="task-abc",
+            end_time=datetime(2026, 1, 1, tzinfo=timezone.utc),
+        )
+        mock_service.end_span.return_value = expected
+
+        params = EndSpanParams(trace_id="trace-123", span=span)
+        result = await env.run(activities.end_span, params)
+
+        assert result == expected
+        assert result.task_id == "task-abc"
+        mock_service.end_span.assert_called_once_with(trace_id="trace-123", span=span)