From ddaf7b2165f5e0f986072a902184d619869ef661 Mon Sep 17 00:00:00 2001
From: Dan Davison <dan.davison@temporal.io>
Date: Fri, 17 Jan 2025 22:34:51 -0500
Subject: [PATCH 1/3] Failing test

---
 tests/worker/test_interceptor.py | 39 ++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/worker/test_interceptor.py b/tests/worker/test_interceptor.py
index a9e726d5..95b2c327 100644
--- a/tests/worker/test_interceptor.py
+++ b/tests/worker/test_interceptor.py
@@ -283,3 +283,42 @@ def pop_trace(name: str, filter: Optional[Callable[[Any], bool]] = None) -> Any:
 
         # Confirm no unexpected traces
         assert not interceptor_traces
+
+
+class WorkflowInstanceAccessInterceptor(Interceptor):
+    def workflow_interceptor_class(
+        self, input: WorkflowInterceptorClassInput
+    ) -> Optional[Type[WorkflowInboundInterceptor]]:
+        return WorkflowInstanceAccessInboundInterceptor
+
+
+class WorkflowInstanceAccessInboundInterceptor(WorkflowInboundInterceptor):
+    async def execute_workflow(self, input: ExecuteWorkflowInput) -> int:
+        # Return integer difference between ids of workflow instance obtained from workflow run method and
+        # from workflow.instance(). They should be the same, so the difference should be 0.
+        id_from_workflow_run_method = await super().execute_workflow(input)
+        id_from_workflow_instance_api = id(workflow.instance())
+        return id_from_workflow_run_method - id_from_workflow_instance_api
+
+
+@workflow.defn
+class WorkflowInstanceAccessWorkflow:
+    @workflow.run
+    async def run(self) -> int:
+        return id(self)
+
+
+async def test_workflow_instance_access_from_interceptor(client: Client):
+    task_queue = f"task_queue_{uuid.uuid4()}"
+    async with Worker(
+        client,
+        task_queue=task_queue,
+        workflows=[WorkflowInstanceAccessWorkflow],
+        interceptors=[WorkflowInstanceAccessInterceptor()],
+    ):
+        difference = await client.execute_workflow(
+            WorkflowInstanceAccessWorkflow.run,
+            id=f"workflow_{uuid.uuid4()}",
+            task_queue=task_queue,
+        )
+        assert difference == 0

From def451b7d2ffe2b7225037955772e17a2dd63572 Mon Sep 17 00:00:00 2001
From: Dan Davison <dan.davison@temporal.io>
Date: Fri, 17 Jan 2025 22:44:12 -0500
Subject: [PATCH 2/3] Implement

---
 temporalio/worker/_workflow_instance.py |  3 +++
 temporalio/workflow.py                  | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/temporalio/worker/_workflow_instance.py b/temporalio/worker/_workflow_instance.py
index c33796ef..5f24d684 100644
--- a/temporalio/worker/_workflow_instance.py
+++ b/temporalio/worker/_workflow_instance.py
@@ -1023,6 +1023,9 @@ def workflow_get_update_validator(self, name: Optional[str]) -> Optional[Callabl
     def workflow_info(self) -> temporalio.workflow.Info:
         return self._outbound.info()
 
+    def workflow_instance(self) -> Any:
+        return self._object
+
     def workflow_is_continue_as_new_suggested(self) -> bool:
         return self._continue_as_new_suggested
 
diff --git a/temporalio/workflow.py b/temporalio/workflow.py
index 6351bace..bf57e928 100644
--- a/temporalio/workflow.py
+++ b/temporalio/workflow.py
@@ -625,6 +625,9 @@ def workflow_get_update_validator(
     @abstractmethod
     def workflow_info(self) -> Info: ...
 
+    @abstractmethod
+    def workflow_instance(self) -> Any: ...
+
     @abstractmethod
     def workflow_is_continue_as_new_suggested(self) -> bool: ...
 
@@ -818,6 +821,15 @@ def info() -> Info:
     return _Runtime.current().workflow_info()
 
 
+def instance() -> Any:
+    """Current workflow's instance.
+
+    Returns:
+        The currently running workflow instance.
+    """
+    return _Runtime.current().workflow_instance()
+
+
 def memo() -> Mapping[str, Any]:
     """Current workflow's memo values, converted without type hints.
 

From 87e80fe8e7cbac5db64982b3e46a89da9942ff39 Mon Sep 17 00:00:00 2001
From: Dan Davison <dan.davison@temporal.io>
Date: Thu, 23 Jan 2025 08:56:35 -0500
Subject: [PATCH 3/3] Add assertion that instance is non-None

---
 tests/worker/test_interceptor.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/worker/test_interceptor.py b/tests/worker/test_interceptor.py
index 95b2c327..1392cd35 100644
--- a/tests/worker/test_interceptor.py
+++ b/tests/worker/test_interceptor.py
@@ -296,8 +296,10 @@ class WorkflowInstanceAccessInboundInterceptor(WorkflowInboundInterceptor):
     async def execute_workflow(self, input: ExecuteWorkflowInput) -> int:
         # Return integer difference between ids of workflow instance obtained from workflow run method and
         # from workflow.instance(). They should be the same, so the difference should be 0.
+        from_workflow_instance_api = workflow.instance()
+        assert from_workflow_instance_api is not None
+        id_from_workflow_instance_api = id(from_workflow_instance_api)
         id_from_workflow_run_method = await super().execute_workflow(input)
-        id_from_workflow_instance_api = id(workflow.instance())
         return id_from_workflow_run_method - id_from_workflow_instance_api