feat: Always set create_tracker as callable that returns a tracker

The create_tracker field on AIConfig is now always a callable that
returns a working tracker, even when the config is disabled. The
factory is always set to tracker_factory — callers use the enabled
flag to decide whether to proceed, not the factory result.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jsonbailey

packages/sdk/server-ai/src/ldai/client.py

@@ -96,7 +96,7 @@ def _completion_config(
             messages=messages,
             provider=provider,
             tracker=tracker,
-            create_tracker=tracker_factory if enabled else None,
+            create_tracker=tracker_factory,
             judge_configuration=judge_configuration,
         )
 
@@ -182,7 +182,7 @@ def _extract_evaluation_metric_key(variation: Dict[str, Any]) -> Optional[str]:
             messages=messages,
             provider=provider,
             tracker=tracker,
-            create_tracker=tracker_factory if enabled else None,
+            create_tracker=tracker_factory,
         )
 
         return config
@@ -268,7 +268,7 @@ async def create_judge(
                 key, context, default or AIJudgeConfigDefault.disabled(), extended_variables
             )
 
-            if not judge_config.enabled or not judge_config.create_tracker:
+            if not judge_config.enabled:
                 return None
 
             provider = RunnerFactory.create_model(judge_config, default_ai_provider)
@@ -365,7 +365,7 @@ async def create_model(
         log.debug(f"Creating managed model for key: {key}")
         config = self._completion_config(key, context, default or AICompletionConfigDefault.disabled(), variables)
 
-        if not config.enabled or not config.create_tracker:
+        if not config.enabled:
             return None
 
         runner = RunnerFactory.create_model(config, default_ai_provider)
@@ -448,7 +448,7 @@ async def create_agent(
         log.debug(f"Creating managed agent for key: {key}")
         config = self.__evaluate_agent(key, context, default or AIAgentConfigDefault.disabled(), variables)
 
-        if not config.enabled or not config.create_tracker:
+        if not config.enabled:
             return None
 
         runner = RunnerFactory.create_agent(config, tools or {}, default_ai_provider)
@@ -901,7 +901,7 @@ def __evaluate_agent(
             provider=provider or default.provider,
             instructions=final_instructions,
             tracker=tracker,
-            create_tracker=tracker_factory if enabled else None,
+            create_tracker=tracker_factory,
             judge_configuration=judge_configuration or default.judge_configuration,
         )
 

packages/sdk/server-ai/src/ldai/managed_agent.py

@@ -30,7 +30,7 @@ async def run(self, input: str) -> AgentResult:
         :param input: The user prompt or input to the agent
         :return: AgentResult containing the agent's output and metrics
         """
-        tracker = self._ai_config.create_tracker() if self._ai_config.create_tracker else self._tracker
+        tracker = self._ai_config.create_tracker()
         return await tracker.track_metrics_of_async(
             lambda: self._agent_runner.run(input),
             lambda result: result.metrics,

packages/sdk/server-ai/src/ldai/managed_model.py

@@ -42,7 +42,7 @@ async def invoke(self, prompt: str) -> ModelResponse:
         :param prompt: The user prompt to send to the model
         :return: ModelResponse containing the model's response and metrics
         """
-        tracker = self._ai_config.create_tracker() if self._ai_config.create_tracker else self._tracker
+        tracker = self._ai_config.create_tracker()
 
         user_message = LDMessage(role='user', content=prompt)
         self._messages.append(user_message)

packages/sdk/server-ai/src/ldai/models.py

@@ -181,7 +181,7 @@ class AIConfig:
     model: Optional[ModelConfig] = None
     provider: Optional[ProviderConfig] = None
     tracker: Optional[Any] = None
-    create_tracker: Optional[Callable[[], Any]] = None
+    create_tracker: Callable[[], Any] = lambda: None
 
     def _base_to_dict(self) -> Dict[str, Any]:
         """

packages/sdk/server-ai/tests/test_managed_agent.py

@@ -55,7 +55,6 @@ class TestManagedAgentRun:
     async def test_run_delegates_to_agent_runner(self):
         """Should delegate run() to the underlying AgentRunner."""
         mock_config = MagicMock(spec=AIAgentConfig)
-        mock_config.create_tracker = None  # fall back to passed tracker
         mock_tracker = MagicMock()
         mock_tracker.track_metrics_of_async = AsyncMock(
             return_value=AgentResult(
@@ -64,6 +63,7 @@ async def test_run_delegates_to_agent_runner(self):
                 metrics=LDAIMetrics(success=True, usage=None),
             )
         )
+        mock_config.create_tracker = MagicMock(return_value=mock_tracker)
         mock_runner = MagicMock()
         mock_runner.run = AsyncMock(
             return_value=AgentResult(

packages/sdk/server-ai/tests/test_model_config.py

@@ -425,14 +425,16 @@ def test_enabled_config_has_create_tracker(ldai_client: LDAIClient):
     assert callable(config.create_tracker)
 
 
-def test_disabled_config_has_no_create_tracker(ldai_client: LDAIClient):
+def test_disabled_config_has_working_create_tracker(ldai_client: LDAIClient):
     context = Context.create('user-key')
     default = AICompletionConfigDefault(enabled=False, model=ModelConfig('fake-model'), messages=[])
 
     config = ldai_client.completion_config('off-config', context, default)
 
     assert config.enabled is False
-    assert config.create_tracker is None
+    assert callable(config.create_tracker)
+    tracker = config.create_tracker()
+    assert tracker is not None
 
 
 def test_create_tracker_returns_new_tracker_each_call(ldai_client: LDAIClient):