From 73c141e04e491d0792c5631e17e47ecafc39353a Mon Sep 17 00:00:00 2001
From: Albert Callarisa <albert@diagrid.io>
Date: Thu, 22 Jan 2026 14:58:04 +0100
Subject: [PATCH] Hook otel instrumentation when available

Signed-off-by: Albert Callarisa <albert@diagrid.io>
---
 durabletask/aio/client.py |  7 ++++
 durabletask/client.py     |  6 ++++
 durabletask/worker.py     | 73 +++++++++++++++++++++++++++------------
 3 files changed, 63 insertions(+), 23 deletions(-)

diff --git a/durabletask/aio/client.py b/durabletask/aio/client.py
index 9b93b96d..a57fe019 100644
--- a/durabletask/aio/client.py
+++ b/durabletask/aio/client.py
@@ -24,6 +24,13 @@
     new_orchestration_state,
 )
 
+# If `opentelemetry-instrumentation-grpc` is available, enable the gRPC client interceptor
+try:
+    from opentelemetry.instrumentation.grpc import GrpcInstrumentorClient
+    GrpcInstrumentorClient().instrument()
+except ImportError:
+    pass
+
 
 class AsyncTaskHubGrpcClient:
     def __init__(
diff --git a/durabletask/client.py b/durabletask/client.py
index e3d391fc..7d86414f 100644
--- a/durabletask/client.py
+++ b/durabletask/client.py
@@ -21,6 +21,12 @@
 TInput = TypeVar("TInput")
 TOutput = TypeVar("TOutput")
 
+# If `opentelemetry-instrumentation-grpc` is available, enable the gRPC client interceptor
+try:
+    from opentelemetry.instrumentation.grpc import GrpcInstrumentorClient
+    GrpcInstrumentorClient().instrument()
+except ImportError:
+    pass
 
 class OrchestrationStatus(Enum):
     """The status of an orchestration instance."""
diff --git a/durabletask/worker.py b/durabletask/worker.py
index 5ad1cccb..7764f98a 100644
--- a/durabletask/worker.py
+++ b/durabletask/worker.py
@@ -2,6 +2,7 @@
 # Licensed under the MIT License.
 
 import asyncio
+import contextlib
 import inspect
 import logging
 import os
@@ -26,6 +27,17 @@
 TInput = TypeVar("TInput")
 TOutput = TypeVar("TOutput")
 
+# If `opentelemetry-sdk` is available, enable the tracer
+try:
+    from opentelemetry import trace
+    from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator
+
+    otel_propagator = TraceContextTextMapPropagator()
+    otel_tracer = trace.get_tracer(__name__)
+except ImportError:
+    otel_tracer = None
+
+
 
 def _log_all_threads(logger: logging.Logger, context: str = ""):
     """Helper function to log all currently active threads for debugging."""
@@ -759,31 +771,46 @@ def _execute_activity(
         completionToken,
     ):
         instance_id = req.orchestrationInstance.instanceId
-        try:
-            executor = _ActivityExecutor(self._registry, self._logger)
-            result = executor.execute(instance_id, req.name, req.taskId, req.input.value)
-            res = pb.ActivityResponse(
-                instanceId=instance_id,
-                taskId=req.taskId,
-                result=ph.get_string_value(result),
-                completionToken=completionToken,
-            )
-        except Exception as ex:
-            res = pb.ActivityResponse(
-                instanceId=instance_id,
-                taskId=req.taskId,
-                failureDetails=ph.new_failure_details(ex),
-                completionToken=completionToken,
-            )
 
-        try:
-            stub.CompleteActivityTask(res)
-        except grpc.RpcError as rpc_error:  # type: ignore
-            self._handle_grpc_execution_error(rpc_error, "activity")
-        except Exception as ex:
-            self._logger.exception(
-                f"Failed to deliver activity response for '{req.name}#{req.taskId}' of orchestration ID '{instance_id}' to sidecar: {ex}"
+        if otel_tracer is not None:
+            span_context = otel_tracer.start_as_current_span(
+                name=f'activity: {req.name}',
+                context=otel_propagator.extract(carrier={"traceparent": req.parentTraceContext.traceParent}),
+                attributes={
+                    "durabletask.task.instance_id": instance_id,
+                    "durabletask.task.id": req.taskId,
+                    "durabletask.activity.name": req.name,
+                }
             )
+        else:
+            span_context = contextlib.nullcontext()
+
+        with span_context:
+            try:
+                executor = _ActivityExecutor(self._registry, self._logger)
+                result = executor.execute(instance_id, req.name, req.taskId, req.input.value)
+                res = pb.ActivityResponse(
+                    instanceId=instance_id,
+                    taskId=req.taskId,
+                    result=ph.get_string_value(result),
+                    completionToken=completionToken,
+                )
+            except Exception as ex:
+                res = pb.ActivityResponse(
+                    instanceId=instance_id,
+                    taskId=req.taskId,
+                    failureDetails=ph.new_failure_details(ex),
+                    completionToken=completionToken,
+                )
+
+            try:
+                stub.CompleteActivityTask(res)
+            except grpc.RpcError as rpc_error:  # type: ignore
+                self._handle_grpc_execution_error(rpc_error, "activity")
+            except Exception as ex:
+                self._logger.exception(
+                    f"Failed to deliver activity response for '{req.name}#{req.taskId}' of orchestration ID '{instance_id}' to sidecar: {ex}"
+                )
 
 
 class _RuntimeOrchestrationContext(