diff --git a/src/google/adk/auth/auth_credential.py b/src/google/adk/auth/auth_credential.py
index ed2ec48..fae4fba 100644
--- a/src/google/adk/auth/auth_credential.py
+++ b/src/google/adk/auth/auth_credential.py
@@ -15,13 +15,18 @@
 from enum import Enum
 from typing import Any, Dict, List, Optional
 
+from pydantic import alias_generators
 from pydantic import BaseModel
 from pydantic import ConfigDict
 from pydantic import Field
 
 
 class BaseModelWithConfig(BaseModel):
-  model_config = ConfigDict(extra="allow")
+  model_config = ConfigDict(
+      extra="allow",
+      alias_generator=alias_generators.to_camel,
+      populate_by_name=True,
+  )
   """The pydantic model config."""
 
 
diff --git a/src/google/adk/auth/auth_tool.py b/src/google/adk/auth/auth_tool.py
index 91bdf68..d560424 100644
--- a/src/google/adk/auth/auth_tool.py
+++ b/src/google/adk/auth/auth_tool.py
@@ -12,13 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from pydantic import BaseModel
-
 from .auth_credential import AuthCredential
+from .auth_credential import BaseModelWithConfig
 from .auth_schemes import AuthScheme
 
 
-class AuthConfig(BaseModel):
+class AuthConfig(BaseModelWithConfig):
   """The auth config sent by tool asking client to collect auth credentials and
 
   adk and client will help to fill in the response
@@ -45,7 +44,7 @@ class AuthConfig(BaseModel):
   this field"""
 
 
-class AuthToolArguments(BaseModel):
+class AuthToolArguments(BaseModelWithConfig):
   """the arguments for the special long running function tool that is used to
 
   request end user credentials.
diff --git a/src/google/adk/cli/cli_eval.py b/src/google/adk/cli/cli_eval.py
index b1d09d3..f2f2586 100644
--- a/src/google/adk/cli/cli_eval.py
+++ b/src/google/adk/cli/cli_eval.py
@@ -30,6 +30,7 @@ from pydantic import Field
 
 from ..agents import Agent
 from ..sessions.session import Session
+from .utils import common
 
 logger = logging.getLogger(__name__)
 
@@ -50,7 +51,7 @@ class EvalMetricResult(BaseModel):
   eval_status: EvalStatus
 
 
-class EvalCaseResult(BaseModel):
+class EvalCaseResult(common.BaseModel):
   eval_set_file: str
   eval_id: str
   final_eval_status: EvalStatus
@@ -60,7 +61,7 @@ class EvalCaseResult(BaseModel):
   user_id: Optional[str] = None
 
 
-class EvalSetResult(BaseModel):
+class EvalSetResult(common.BaseModel):
   eval_set_result_id: str
   eval_set_result_name: str
   eval_set_id: str
diff --git a/src/google/adk/events/event.py b/src/google/adk/events/event.py
index c36f6fc..c3b8b86 100644
--- a/src/google/adk/events/event.py
+++ b/src/google/adk/events/event.py
@@ -19,6 +19,7 @@ import string
 from typing import Optional
 
 from google.genai import types
+from pydantic import alias_generators
 from pydantic import ConfigDict
 from pydantic import Field
 
@@ -46,7 +47,11 @@ class Event(LlmResponse):
   """
 
   model_config = ConfigDict(
-      extra='forbid', ser_json_bytes='base64', val_json_bytes='base64'
+      extra='forbid',
+      ser_json_bytes='base64',
+      val_json_bytes='base64',
+      alias_generator=alias_generators.to_camel,
+      populate_by_name=True,
   )
   """The pydantic model config."""
 
diff --git a/src/google/adk/events/event_actions.py b/src/google/adk/events/event_actions.py
index 6597edb..994a790 100644
--- a/src/google/adk/events/event_actions.py
+++ b/src/google/adk/events/event_actions.py
@@ -16,6 +16,7 @@ from __future__ import annotations
 
 from typing import Optional
 
+from pydantic import alias_generators
 from pydantic import BaseModel
 from pydantic import ConfigDict
 from pydantic import Field
@@ -26,7 +27,11 @@ from ..auth.auth_tool import AuthConfig
 class EventActions(BaseModel):
   """Represents the actions attached to an event."""
 
-  model_config = ConfigDict(extra='forbid')
+  model_config = ConfigDict(
+      extra='forbid',
+      alias_generator=alias_generators.to_camel,
+      populate_by_name=True,
+  )
   """The pydantic model config."""
 
   skip_summarization: Optional[bool] = None
diff --git a/src/google/adk/models/llm_response.py b/src/google/adk/models/llm_response.py
index 353af5d..6fcb4e2 100644
--- a/src/google/adk/models/llm_response.py
+++ b/src/google/adk/models/llm_response.py
@@ -17,6 +17,7 @@ from __future__ import annotations
 from typing import Any, Optional
 
 from google.genai import types
+from pydantic import alias_generators
 from pydantic import BaseModel
 from pydantic import ConfigDict
 
@@ -40,7 +41,11 @@ class LlmResponse(BaseModel):
     custom_metadata: The custom metadata of the LlmResponse.
   """
 
-  model_config = ConfigDict(extra='forbid')
+  model_config = ConfigDict(
+      extra='forbid',
+      alias_generator=alias_generators.to_camel,
+      populate_by_name=True,
+  )
   """The pydantic model config."""
 
   content: Optional[types.Content] = None