diff --git a/src/crewai/agent.py b/src/crewai/agent.py
index e137a1e41..b1f806973 100644
--- a/src/crewai/agent.py
+++ b/src/crewai/agent.py
@@ -113,10 +113,11 @@ class Agent(BaseAgent):
         description="Maximum number of retries for an agent to execute a task when an error occurs.",
     )
 
-    def __init__(__pydantic_self__, **data):
-        config = data.pop("config", {})
-        super().__init__(**config, **data)
-        __pydantic_self__.agent_ops_agent_name = __pydantic_self__.role
+    @model_validator(mode="after")
+    def set_agent_ops_agent_name(self) -> "Agent":
+        """Set agent ops agent name."""
+        self.agent_ops_agent_name = self.role
+        return self
 
     @model_validator(mode="after")
     def set_agent_executor(self) -> "Agent":
@@ -213,7 +214,7 @@ class Agent(BaseAgent):
                 raise e
             result = self.execute_task(task, context, tools)
 
-        if self.max_rpm:
+        if self.max_rpm and self._rpm_controller:
             self._rpm_controller.stop_rpm_counter()
 
         # If there was any tool in self.tools_results that had result_as_answer
diff --git a/src/crewai/agents/agent_builder/base_agent.py b/src/crewai/agents/agent_builder/base_agent.py
index 22790827a..0c0ebcef5 100644
--- a/src/crewai/agents/agent_builder/base_agent.py
+++ b/src/crewai/agents/agent_builder/base_agent.py
@@ -7,7 +7,6 @@ from typing import Any, Dict, List, Optional, TypeVar
 from pydantic import (
     UUID4,
     BaseModel,
-    ConfigDict,
     Field,
     InstanceOf,
     PrivateAttr,
@@ -74,12 +73,17 @@ class BaseAgent(ABC, BaseModel):
     """
 
     __hash__ = object.__hash__  # type: ignore
-    _logger: Logger = PrivateAttr()
-    _rpm_controller: RPMController = PrivateAttr(default=None)
+    _logger: Logger = PrivateAttr(default_factory=lambda: Logger(verbose=False))
+    _rpm_controller: Optional[RPMController] = PrivateAttr(default=None)
     _request_within_rpm_limit: Any = PrivateAttr(default=None)
-    formatting_errors: int = 0
-    model_config = ConfigDict(arbitrary_types_allowed=True)
+    _original_role: Optional[str] = PrivateAttr(default=None)
+    _original_goal: Optional[str] = PrivateAttr(default=None)
+    _original_backstory: Optional[str] = PrivateAttr(default=None)
+    _token_process: TokenProcess = PrivateAttr(default_factory=TokenProcess)
     id: UUID4 = Field(default_factory=uuid.uuid4, frozen=True)
+    formatting_errors: int = Field(
+        default=0, description="Number of formatting errors."
+    )
     role: str = Field(description="Role of the agent")
     goal: str = Field(description="Objective of the agent")
     backstory: str = Field(description="Backstory of the agent")
@@ -123,15 +127,6 @@ class BaseAgent(ABC, BaseModel):
         default=None, description="Maximum number of tokens for the agent's execution."
     )
 
-    _original_role: str | None = None
-    _original_goal: str | None = None
-    _original_backstory: str | None = None
-    _token_process: TokenProcess = TokenProcess()
-
-    def __init__(__pydantic_self__, **data):
-        config = data.pop("config", {})
-        super().__init__(**config, **data)
-
     @model_validator(mode="after")
     def set_config_attributes(self):
         if self.config:
diff --git a/src/crewai/agents/cache/cache_handler.py b/src/crewai/agents/cache/cache_handler.py
index 27dccbcb5..09dd76f26 100644
--- a/src/crewai/agents/cache/cache_handler.py
+++ b/src/crewai/agents/cache/cache_handler.py
@@ -1,13 +1,12 @@
-from typing import Optional
+from typing import Any, Dict, Optional
+
+from pydantic import BaseModel, PrivateAttr
 
 
-class CacheHandler:
+class CacheHandler(BaseModel):
     """Callback handler for tool usage."""
 
-    _cache: dict = {}
-
-    def __init__(self):
-        self._cache = {}
+    _cache: Dict[str, Any] = PrivateAttr(default_factory=dict)
 
     def add(self, tool, input, output):
         self._cache[f"{tool}-{input}"] = output
diff --git a/src/crewai/crew.py b/src/crewai/crew.py
index 8125f0255..87f3f29f6 100644
--- a/src/crewai/crew.py
+++ b/src/crewai/crew.py
@@ -10,7 +10,6 @@ from langchain_core.callbacks import BaseCallbackHandler
 from pydantic import (
     UUID4,
     BaseModel,
-    ConfigDict,
     Field,
     InstanceOf,
     Json,
@@ -105,7 +104,6 @@ class Crew(BaseModel):
 
     name: Optional[str] = Field(default=None)
     cache: bool = Field(default=True)
-    model_config = ConfigDict(arbitrary_types_allowed=True)
     tasks: List[Task] = Field(default_factory=list)
     agents: List[BaseAgent] = Field(default_factory=list)
     process: Process = Field(default=Process.sequential)
diff --git a/src/crewai/project/crew_base.py b/src/crewai/project/crew_base.py
index 90db88b7c..5e0f154ea 100644
--- a/src/crewai/project/crew_base.py
+++ b/src/crewai/project/crew_base.py
@@ -4,14 +4,12 @@ from typing import Any, Callable, Dict
 
 import yaml
 from dotenv import load_dotenv
-from pydantic import ConfigDict
 
 load_dotenv()
 
 
 def CrewBase(cls):
     class WrappedClass(cls):
-        model_config = ConfigDict(arbitrary_types_allowed=True)
         is_crew_class: bool = True  # type: ignore
 
         # Get the directory of the class being decorated
diff --git a/src/crewai/project/pipeline_base.py b/src/crewai/project/pipeline_base.py
index 3f2340301..268cb3901 100644
--- a/src/crewai/project/pipeline_base.py
+++ b/src/crewai/project/pipeline_base.py
@@ -1,24 +1,24 @@
-from typing import Callable, Dict
-
-from pydantic import ConfigDict
+from typing import Any, Callable, Dict, List, Type, Union
 
 from crewai.crew import Crew
 from crewai.pipeline.pipeline import Pipeline
 from crewai.routers.router import Router
 
+PipelineStage = Union[Crew, List[Crew], Router]
+
 
 # TODO: Could potentially remove. Need to check with @joao and @gui if this is needed for CrewAI+
-def PipelineBase(cls):
+def PipelineBase(cls: Type[Any]) -> Type[Any]:
     class WrappedClass(cls):
-        model_config = ConfigDict(arbitrary_types_allowed=True)
         is_pipeline_class: bool = True  # type: ignore
+        stages: List[PipelineStage]
 
-        def __init__(self, *args, **kwargs):
+        def __init__(self, *args: Any, **kwargs: Any) -> None:
             super().__init__(*args, **kwargs)
             self.stages = []
             self._map_pipeline_components()
 
-        def _get_all_functions(self):
+        def _get_all_functions(self) -> Dict[str, Callable[..., Any]]:
             return {
                 name: getattr(self, name)
                 for name in dir(self)
@@ -26,15 +26,15 @@ def PipelineBase(cls):
             }
 
         def _filter_functions(
-            self, functions: Dict[str, Callable], attribute: str
-        ) -> Dict[str, Callable]:
+            self, functions: Dict[str, Callable[..., Any]], attribute: str
+        ) -> Dict[str, Callable[..., Any]]:
             return {
                 name: func
                 for name, func in functions.items()
                 if hasattr(func, attribute)
             }
 
-        def _map_pipeline_components(self):
+        def _map_pipeline_components(self) -> None:
             all_functions = self._get_all_functions()
             crew_functions = self._filter_functions(all_functions, "is_crew")
             router_functions = self._filter_functions(all_functions, "is_router")
diff --git a/src/crewai/routers/router.py b/src/crewai/routers/router.py
index 76549565b..e85ce2256 100644
--- a/src/crewai/routers/router.py
+++ b/src/crewai/routers/router.py
@@ -1,32 +1,26 @@
 from copy import deepcopy
-from typing import Any, Callable, Dict, Generic, Tuple, TypeVar
+from typing import Any, Callable, Dict, Tuple
 
 from pydantic import BaseModel, Field, PrivateAttr
 
-T = TypeVar("T", bound=Dict[str, Any])
-U = TypeVar("U")
+
+class Route(BaseModel):
+    condition: Callable[[Dict[str, Any]], bool]
+    pipeline: Any
 
 
-class Route(Generic[T, U]):
-    condition: Callable[[T], bool]
-    pipeline: U
-
-    def __init__(self, condition: Callable[[T], bool], pipeline: U):
-        self.condition = condition
-        self.pipeline = pipeline
-
-
-class Router(BaseModel, Generic[T, U]):
-    routes: Dict[str, Route[T, U]] = Field(
+class Router(BaseModel):
+    routes: Dict[str, Route] = Field(
         default_factory=dict,
         description="Dictionary of route names to (condition, pipeline) tuples",
     )
-    default: U = Field(..., description="Default pipeline if no conditions are met")
+    default: Any = Field(..., description="Default pipeline if no conditions are met")
     _route_types: Dict[str, type] = PrivateAttr(default_factory=dict)
 
-    model_config = {"arbitrary_types_allowed": True}
+    class Config:
+        arbitrary_types_allowed = True
 
-    def __init__(self, routes: Dict[str, Route[T, U]], default: U, **data):
+    def __init__(self, routes: Dict[str, Route], default: Any, **data):
         super().__init__(routes=routes, default=default, **data)
         self._check_copyable(default)
         for name, route in routes.items():
@@ -34,16 +28,16 @@ class Router(BaseModel, Generic[T, U]):
             self._route_types[name] = type(route.pipeline)
 
     @staticmethod
-    def _check_copyable(obj):
+    def _check_copyable(obj: Any) -> None:
         if not hasattr(obj, "copy") or not callable(getattr(obj, "copy")):
             raise ValueError(f"Object of type {type(obj)} must have a 'copy' method")
 
     def add_route(
         self,
         name: str,
-        condition: Callable[[T], bool],
-        pipeline: U,
-    ) -> "Router[T, U]":
+        condition: Callable[[Dict[str, Any]], bool],
+        pipeline: Any,
+    ) -> "Router":
         """
         Add a named route with its condition and corresponding pipeline to the router.
 
@@ -60,7 +54,7 @@ class Router(BaseModel, Generic[T, U]):
         self._route_types[name] = type(pipeline)
         return self
 
-    def route(self, input_data: T) -> Tuple[U, str]:
+    def route(self, input_data: Dict[str, Any]) -> Tuple[Any, str]:
         """
         Evaluate the input against the conditions and return the appropriate pipeline.
 
@@ -76,15 +70,15 @@ class Router(BaseModel, Generic[T, U]):
 
         return self.default, "default"
 
-    def copy(self) -> "Router[T, U]":
+    def copy(self) -> "Router":
         """Create a deep copy of the Router."""
         new_routes = {
             name: Route(
                 condition=deepcopy(route.condition),
-                pipeline=route.pipeline.copy(),  # type: ignore
+                pipeline=route.pipeline.copy(),
             )
             for name, route in self.routes.items()
         }
-        new_default = self.default.copy()  # type: ignore
+        new_default = self.default.copy()
 
         return Router(routes=new_routes, default=new_default)
diff --git a/src/crewai/task.py b/src/crewai/task.py
index 3c8987b64..d00e2cc49 100644
--- a/src/crewai/task.py
+++ b/src/crewai/task.py
@@ -9,7 +9,14 @@ from hashlib import md5
 from typing import Any, Dict, List, Optional, Tuple, Type, Union
 
 from opentelemetry.trace import Span
-from pydantic import UUID4, BaseModel, Field, field_validator, model_validator
+from pydantic import (
+    UUID4,
+    BaseModel,
+    Field,
+    PrivateAttr,
+    field_validator,
+    model_validator,
+)
 from pydantic_core import PydanticCustomError
 
 from crewai.agents.agent_builder.base_agent import BaseAgent
@@ -39,9 +46,6 @@ class Task(BaseModel):
         tools: List of tools/resources limited for task execution.
     """
 
-    class Config:
-        arbitrary_types_allowed = True
-
     __hash__ = object.__hash__  # type: ignore
     used_tools: int = 0
     tools_errors: int = 0
@@ -104,16 +108,12 @@ class Task(BaseModel):
         default=None,
     )
 
-    _telemetry: Telemetry
-    _execution_span: Span | None = None
-    _original_description: str | None = None
-    _original_expected_output: str | None = None
-    _thread: threading.Thread | None = None
-    _execution_time: float | None = None
-
-    def __init__(__pydantic_self__, **data):
-        config = data.pop("config", {})
-        super().__init__(**config, **data)
+    _telemetry: Telemetry = PrivateAttr(default_factory=Telemetry)
+    _execution_span: Optional[Span] = PrivateAttr(default=None)
+    _original_description: Optional[str] = PrivateAttr(default=None)
+    _original_expected_output: Optional[str] = PrivateAttr(default=None)
+    _thread: Optional[threading.Thread] = PrivateAttr(default=None)
+    _execution_time: Optional[float] = PrivateAttr(default=None)
 
     @field_validator("id", mode="before")
     @classmethod
@@ -137,12 +137,6 @@ class Task(BaseModel):
             return value[1:]
         return value
 
-    @model_validator(mode="after")
-    def set_private_attrs(self) -> "Task":
-        """Set private attributes."""
-        self._telemetry = Telemetry()
-        return self
-
     @model_validator(mode="after")
     def set_attributes_based_on_config(self) -> "Task":
         """Set attributes based on the agent configuration."""
@@ -263,9 +257,7 @@ class Task(BaseModel):
             content = (
                 json_output
                 if json_output
-                else pydantic_output.model_dump_json()
-                if pydantic_output
-                else result
+                else pydantic_output.model_dump_json() if pydantic_output else result
             )
             self._save_file(content)
 
diff --git a/src/crewai/tools/cache_tools.py b/src/crewai/tools/cache_tools.py
index 77ff8881b..cc42d07f0 100644
--- a/src/crewai/tools/cache_tools.py
+++ b/src/crewai/tools/cache_tools.py
@@ -1,5 +1,5 @@
 from langchain.tools import StructuredTool
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, Field
 
 from crewai.agents.cache import CacheHandler
 
@@ -7,11 +7,10 @@ from crewai.agents.cache import CacheHandler
 class CacheTools(BaseModel):
     """Default tools to hit the cache."""
 
-    model_config = ConfigDict(arbitrary_types_allowed=True)
     name: str = "Hit Cache"
     cache_handler: CacheHandler = Field(
         description="Cache Handler for the crew",
-        default=CacheHandler(),
+        default_factory=CacheHandler,
     )
 
     def tool(self):
diff --git a/src/crewai/utilities/logger.py b/src/crewai/utilities/logger.py
index 973c694d2..9cf06757a 100644
--- a/src/crewai/utilities/logger.py
+++ b/src/crewai/utilities/logger.py
@@ -1,13 +1,13 @@
 from datetime import datetime
 
+from pydantic import BaseModel, Field, PrivateAttr
+
 from crewai.utilities.printer import Printer
 
 
-class Logger:
-    _printer = Printer()
-
-    def __init__(self, verbose=False):
-        self.verbose = verbose
+class Logger(BaseModel):
+    verbose: bool = Field(default=False)
+    _printer: Printer = PrivateAttr(default_factory=Printer)
 
     def log(self, level, message, color="bold_green"):
         if self.verbose:
diff --git a/src/crewai/utilities/rpm_controller.py b/src/crewai/utilities/rpm_controller.py
index 761760bf8..5ee054c5f 100644
--- a/src/crewai/utilities/rpm_controller.py
+++ b/src/crewai/utilities/rpm_controller.py
@@ -1,44 +1,50 @@
 import threading
 import time
-from typing import Union
+from typing import Optional
 
-from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator
+from pydantic import BaseModel, Field, PrivateAttr, model_validator
 
 from crewai.utilities.logger import Logger
 
 
 class RPMController(BaseModel):
-    model_config = ConfigDict(arbitrary_types_allowed=True)
-    max_rpm: Union[int, None] = Field(default=None)
-    logger: Logger = Field(default=None)
+    max_rpm: Optional[int] = Field(default=None)
+    logger: Logger = Field(default_factory=lambda: Logger(verbose=False))
     _current_rpm: int = PrivateAttr(default=0)
-    _timer: threading.Timer | None = PrivateAttr(default=None)
-    _lock: threading.Lock = PrivateAttr(default=None)
-    _shutdown_flag = False
+    _timer: Optional[threading.Timer] = PrivateAttr(default=None)
+    _lock: Optional[threading.Lock] = PrivateAttr(default=None)
+    _shutdown_flag: bool = PrivateAttr(default=False)
 
     @model_validator(mode="after")
     def reset_counter(self):
-        if self.max_rpm:
+        if self.max_rpm is not None:
             if not self._shutdown_flag:
                 self._lock = threading.Lock()
                 self._reset_request_count()
         return self
 
     def check_or_wait(self):
-        if not self.max_rpm:
+        if self.max_rpm is None:
             return True
 
-        with self._lock:
-            if self._current_rpm < self.max_rpm:
+        def _check_and_increment():
+            if self.max_rpm is not None and self._current_rpm < self.max_rpm:
                 self._current_rpm += 1
                 return True
-            else:
+            elif self.max_rpm is not None:
                 self.logger.log(
                     "info", "Max RPM reached, waiting for next minute to start."
                 )
                 self._wait_for_next_minute()
                 self._current_rpm = 1
                 return True
+            return True
+
+        if self._lock:
+            with self._lock:
+                return _check_and_increment()
+        else:
+            return _check_and_increment()
 
     def stop_rpm_counter(self):
         if self._timer:
@@ -50,10 +56,18 @@ class RPMController(BaseModel):
         self._current_rpm = 0
 
     def _reset_request_count(self):
-        with self._lock:
+        def _reset():
             self._current_rpm = 0
+            if not self._shutdown_flag:
+                self._timer = threading.Timer(60.0, self._reset_request_count)
+                self._timer.start()
+
+        if self._lock:
+            with self._lock:
+                _reset()
+        else:
+            _reset()
+
         if self._timer:
             self._shutdown_flag = True
             self._timer.cancel()
-        self._timer = threading.Timer(60.0, self._reset_request_count)
-        self._timer.start()
diff --git a/tests/agent_test.py b/tests/agent_test.py
index 95e975f6a..d90e35845 100644
--- a/tests/agent_test.py
+++ b/tests/agent_test.py
@@ -4,11 +4,6 @@ from unittest import mock
 from unittest.mock import patch
 
 import pytest
-from langchain.tools import tool
-from langchain_core.exceptions import OutputParserException
-from langchain_openai import ChatOpenAI
-from langchain.schema import AgentAction
-
 from crewai import Agent, Crew, Task
 from crewai.agents.cache import CacheHandler
 from crewai.agents.executor import CrewAgentExecutor
@@ -16,6 +11,10 @@ from crewai.agents.parser import CrewAgentParser
 from crewai.tools.tool_calling import InstructorToolCalling
 from crewai.tools.tool_usage import ToolUsage
 from crewai.utilities import RPMController
+from langchain.schema import AgentAction
+from langchain.tools import tool
+from langchain_core.exceptions import OutputParserException
+from langchain_openai import ChatOpenAI
 
 
 def test_agent_creation():
@@ -817,7 +816,7 @@ def test_agent_definition_based_on_dict():
         "verbose": True,
     }
 
-    agent = Agent(config=config)
+    agent = Agent(**config)
 
     assert agent.role == "test role"
     assert agent.goal == "test goal"
@@ -837,7 +836,7 @@ def test_agent_human_input():
         "backstory": "test backstory",
     }
 
-    agent = Agent(config=config)
+    agent = Agent(**config)
 
     task = Task(
         agent=agent,
diff --git a/tests/crew_test.py b/tests/crew_test.py
index 0ba450fcc..8c85d58c6 100644
--- a/tests/crew_test.py
+++ b/tests/crew_test.py
@@ -8,7 +8,6 @@ from unittest.mock import MagicMock, patch
 
 import pydantic_core
 import pytest
-
 from crewai.agent import Agent
 from crewai.agents.cache import CacheHandler
 from crewai.crew import Crew
diff --git a/tests/task_test.py b/tests/task_test.py
index e4ee23e9f..7bba169b3 100644
--- a/tests/task_test.py
+++ b/tests/task_test.py
@@ -1,8 +1,8 @@
 """Test Agent creation and execution basic functionality."""
 
-import os
 import hashlib
 import json
+import os
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -703,7 +703,7 @@ def test_task_definition_based_on_dict():
         "expected_output": "The score of the title.",
     }
 
-    task = Task(config=config)
+    task = Task(**config)
 
     assert task.description == config["description"]
     assert task.expected_output == config["expected_output"]
@@ -716,7 +716,7 @@ def test_conditional_task_definition_based_on_dict():
         "expected_output": "The score of the title.",
     }
 
-    task = ConditionalTask(config=config, condition=lambda x: True)
+    task = ConditionalTask(**config, condition=lambda x: True)
 
     assert task.description == config["description"]
     assert task.expected_output == config["expected_output"]