fix: Resolve custom_metadata propagation and LiteLLM thought parts issues

contributing/samples/gepa/experiment.py

@@ -43,7 +43,6 @@
 from tau_bench.types import EnvRunResult
 from tau_bench.types import RunConfig
 import tau_bench_agent as tau_bench_agent_lib
-
 import utils
 
 

contributing/samples/gepa/run_experiment.py

@@ -25,7 +25,6 @@
 from absl import flags
 import experiment
 from google.genai import types
-
 import utils
 
 _OUTPUT_DIR = flags.DEFINE_string(

src/google/adk/flows/llm_flows/base_llm_flow.py

@@ -324,6 +324,9 @@ def get_author_for_event(llm_response):
                 id=Event.new_id(),
                 invocation_id=invocation_context.invocation_id,
                 author=get_author_for_event(llm_response),
+                custom_metadata=getattr(
+                    invocation_context.run_config, 'custom_metadata', None
+                ),
             )
 
             async with Aclosing(
@@ -438,6 +441,9 @@ async def _run_one_step_async(
         invocation_id=invocation_context.invocation_id,
         author=invocation_context.agent.name,
         branch=invocation_context.branch,
+        custom_metadata=getattr(
+            invocation_context.run_config, 'custom_metadata', None
+        ),
     )
     async with Aclosing(
         self._call_llm_async(

src/google/adk/models/lite_llm.py

@@ -533,6 +533,10 @@ async def _get_content(
 
   content_objects = []
   for part in parts:
+    # Skip thought parts - these are model reasoning and should not be
+    # fed back as input in subsequent turns
+    if getattr(part, "thought", False):
+      continue
     if part.text:
       if len(parts) == 1:
         return part.text