Merge branch 'main' into lorenze/imp-pydantic

- Changed event type definitions across multiple event classes to use Literal for improved type safety and clarity.
- Updated the  definition in  to utilize Annotated for better schema representation.
- Ensured consistency in type definitions for various events, enhancing the robustness of event handling in the CrewAI framework.

lib/crewai/src/crewai/events/event_types.py

@@ -1,3 +1,7 @@
+from typing import Annotated
+
+from pydantic import Field
+
 from crewai.events.types.a2a_events import (
     A2AAgentCardFetchedEvent,
     A2AArtifactReceivedEvent,
@@ -102,7 +106,7 @@ from crewai.events.types.tool_usage_events import (
 )
 
 
-EventTypes = (
+EventTypes = Annotated[
     A2AAgentCardFetchedEvent
     | A2AArtifactReceivedEvent
     | A2AAuthenticationFailedEvent
@@ -180,5 +184,6 @@ EventTypes = (
     | MCPConnectionFailedEvent
     | MCPToolExecutionStartedEvent
     | MCPToolExecutionCompletedEvent
-    | MCPToolExecutionFailedEvent
+    | MCPToolExecutionFailedEvent,
-)
+    Field(discriminator="type"),
+]

lib/crewai/src/crewai/events/types/a2a_events.py

@@ -73,7 +73,7 @@ class A2ADelegationStartedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_delegation_started"
+    type: Literal["a2a_delegation_started"] = "a2a_delegation_started"
     endpoint: str
     task_description: str
     agent_id: str
@@ -106,7 +106,7 @@ class A2ADelegationCompletedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_delegation_completed"
+    type: Literal["a2a_delegation_completed"] = "a2a_delegation_completed"
     status: str
     result: str | None = None
     error: str | None = None
@@ -140,7 +140,7 @@ class A2AConversationStartedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_conversation_started"
+    type: Literal["a2a_conversation_started"] = "a2a_conversation_started"
     agent_id: str
     endpoint: str
     context_id: str | None = None
@@ -171,7 +171,7 @@ class A2AMessageSentEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_message_sent"
+    type: Literal["a2a_message_sent"] = "a2a_message_sent"
     message: str
     turn_number: int
     context_id: str | None = None
@@ -203,7 +203,7 @@ class A2AResponseReceivedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_response_received"
+    type: Literal["a2a_response_received"] = "a2a_response_received"
     response: str
     turn_number: int
     context_id: str | None = None
@@ -237,7 +237,7 @@ class A2AConversationCompletedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_conversation_completed"
+    type: Literal["a2a_conversation_completed"] = "a2a_conversation_completed"
     status: Literal["completed", "failed"]
     final_result: str | None = None
     error: str | None = None
@@ -263,7 +263,7 @@ class A2APollingStartedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_polling_started"
+    type: Literal["a2a_polling_started"] = "a2a_polling_started"
     task_id: str
     context_id: str | None = None
     polling_interval: float
@@ -286,7 +286,7 @@ class A2APollingStatusEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_polling_status"
+    type: Literal["a2a_polling_status"] = "a2a_polling_status"
     task_id: str
     context_id: str | None = None
     state: str
@@ -309,7 +309,7 @@ class A2APushNotificationRegisteredEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_push_notification_registered"
+    type: Literal["a2a_push_notification_registered"] = "a2a_push_notification_registered"
     task_id: str
     context_id: str | None = None
     callback_url: str
@@ -334,7 +334,7 @@ class A2APushNotificationReceivedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_push_notification_received"
+    type: Literal["a2a_push_notification_received"] = "a2a_push_notification_received"
     task_id: str
     context_id: str | None = None
     state: str
@@ -359,7 +359,7 @@ class A2APushNotificationSentEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_push_notification_sent"
+    type: Literal["a2a_push_notification_sent"] = "a2a_push_notification_sent"
     task_id: str
     context_id: str | None = None
     callback_url: str
@@ -381,7 +381,7 @@ class A2APushNotificationTimeoutEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_push_notification_timeout"
+    type: Literal["a2a_push_notification_timeout"] = "a2a_push_notification_timeout"
     task_id: str
     context_id: str | None = None
     timeout_seconds: float
@@ -405,7 +405,7 @@ class A2AStreamingStartedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_streaming_started"
+    type: Literal["a2a_streaming_started"] = "a2a_streaming_started"
     task_id: str | None = None
     context_id: str | None = None
     endpoint: str
@@ -434,7 +434,7 @@ class A2AStreamingChunkEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_streaming_chunk"
+    type: Literal["a2a_streaming_chunk"] = "a2a_streaming_chunk"
     task_id: str | None = None
     context_id: str | None = None
     chunk: str
@@ -462,7 +462,7 @@ class A2AAgentCardFetchedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_agent_card_fetched"
+    type: Literal["a2a_agent_card_fetched"] = "a2a_agent_card_fetched"
     endpoint: str
     a2a_agent_name: str | None = None
     agent_card: dict[str, Any] | None = None
@@ -486,7 +486,7 @@ class A2AAuthenticationFailedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_authentication_failed"
+    type: Literal["a2a_authentication_failed"] = "a2a_authentication_failed"
     endpoint: str
     auth_type: str | None = None
     error: str
@@ -517,7 +517,7 @@ class A2AArtifactReceivedEvent(A2AEventBase):
         extensions: List of A2A extension URIs in use.
     """
 
-    type: str = "a2a_artifact_received"
+    type: Literal["a2a_artifact_received"] = "a2a_artifact_received"
     task_id: str
     artifact_id: str
     artifact_name: str | None = None
@@ -550,7 +550,7 @@ class A2AConnectionErrorEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_connection_error"
+    type: Literal["a2a_connection_error"] = "a2a_connection_error"
     endpoint: str
     error: str
     error_type: str | None = None
@@ -571,7 +571,7 @@ class A2AServerTaskStartedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_server_task_started"
+    type: Literal["a2a_server_task_started"] = "a2a_server_task_started"
     task_id: str
     context_id: str
     metadata: dict[str, Any] | None = None
@@ -587,7 +587,7 @@ class A2AServerTaskCompletedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_server_task_completed"
+    type: Literal["a2a_server_task_completed"] = "a2a_server_task_completed"
     task_id: str
     context_id: str
     result: str
@@ -603,7 +603,7 @@ class A2AServerTaskCanceledEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_server_task_canceled"
+    type: Literal["a2a_server_task_canceled"] = "a2a_server_task_canceled"
     task_id: str
     context_id: str
     metadata: dict[str, Any] | None = None
@@ -619,7 +619,7 @@ class A2AServerTaskFailedEvent(A2AEventBase):
         metadata: Custom A2A metadata key-value pairs.
     """
 
-    type: str = "a2a_server_task_failed"
+    type: Literal["a2a_server_task_failed"] = "a2a_server_task_failed"
     task_id: str
     context_id: str
     error: str
@@ -634,7 +634,7 @@ class A2AParallelDelegationStartedEvent(A2AEventBase):
         task_description: Description of the task being delegated.
     """
 
-    type: str = "a2a_parallel_delegation_started"
+    type: Literal["a2a_parallel_delegation_started"] = "a2a_parallel_delegation_started"
     endpoints: list[str]
     task_description: str
 
@@ -649,7 +649,7 @@ class A2AParallelDelegationCompletedEvent(A2AEventBase):
         results: Summary of results from each agent.
     """
 
-    type: str = "a2a_parallel_delegation_completed"
+    type: Literal["a2a_parallel_delegation_completed"] = "a2a_parallel_delegation_completed"
     endpoints: list[str]
     success_count: int
     failure_count: int

lib/crewai/src/crewai/events/types/agent_events.py

@@ -2,8 +2,7 @@
 
 from __future__ import annotations
 
-from collections.abc import Sequence
+from typing import Any, Literal
-from typing import Any
 
 from pydantic import ConfigDict, model_validator
 
@@ -18,9 +17,9 @@ class AgentExecutionStartedEvent(BaseEvent):
 
     agent: BaseAgent
     task: Any
-    tools: Sequence[BaseTool | CrewStructuredTool] | None
+    tools: list[BaseTool | CrewStructuredTool] | None
     task_prompt: str
-    type: str = "agent_execution_started"
+    type: Literal["agent_execution_started"] = "agent_execution_started"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
@@ -44,7 +43,7 @@ class AgentExecutionCompletedEvent(BaseEvent):
     agent: BaseAgent
     task: Any
     output: str
-    type: str = "agent_execution_completed"
+    type: Literal["agent_execution_completed"] = "agent_execution_completed"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
@@ -68,7 +67,7 @@ class AgentExecutionErrorEvent(BaseEvent):
     agent: BaseAgent
     task: Any
     error: str
-    type: str = "agent_execution_error"
+    type: Literal["agent_execution_error"] = "agent_execution_error"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
@@ -91,9 +90,9 @@ class LiteAgentExecutionStartedEvent(BaseEvent):
     """Event emitted when a LiteAgent starts executing"""
 
     agent_info: dict[str, Any]
-    tools: Sequence[BaseTool | CrewStructuredTool] | None
+    tools: list[BaseTool | CrewStructuredTool] | None
     messages: str | list[dict[str, str]]
-    type: str = "lite_agent_execution_started"
+    type: Literal["lite_agent_execution_started"] = "lite_agent_execution_started"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
@@ -103,7 +102,7 @@ class LiteAgentExecutionCompletedEvent(BaseEvent):
 
     agent_info: dict[str, Any]
     output: str
-    type: str = "lite_agent_execution_completed"
+    type: Literal["lite_agent_execution_completed"] = "lite_agent_execution_completed"
 
 
 class LiteAgentExecutionErrorEvent(BaseEvent):
@@ -111,7 +110,7 @@ class LiteAgentExecutionErrorEvent(BaseEvent):
 
     agent_info: dict[str, Any]
     error: str
-    type: str = "lite_agent_execution_error"
+    type: Literal["lite_agent_execution_error"] = "lite_agent_execution_error"
 
 
 # Agent Eval events
@@ -120,7 +119,7 @@ class AgentEvaluationStartedEvent(BaseEvent):
     agent_role: str
     task_id: str | None = None
     iteration: int
-    type: str = "agent_evaluation_started"
+    type: Literal["agent_evaluation_started"] = "agent_evaluation_started"
 
 
 class AgentEvaluationCompletedEvent(BaseEvent):
@@ -130,7 +129,7 @@ class AgentEvaluationCompletedEvent(BaseEvent):
     iteration: int
     metric_category: Any
     score: Any
-    type: str = "agent_evaluation_completed"
+    type: Literal["agent_evaluation_completed"] = "agent_evaluation_completed"
 
 
 class AgentEvaluationFailedEvent(BaseEvent):
@@ -139,4 +138,4 @@ class AgentEvaluationFailedEvent(BaseEvent):
     task_id: str | None = None
     iteration: int
     error: str
-    type: str = "agent_evaluation_failed"
+    type: Literal["agent_evaluation_failed"] = "agent_evaluation_failed"

lib/crewai/src/crewai/events/types/crew_events.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -40,14 +40,14 @@ class CrewKickoffStartedEvent(CrewBaseEvent):
     """Event emitted when a crew starts execution"""
 
     inputs: dict[str, Any] | None
-    type: str = "crew_kickoff_started"
+    type: Literal["crew_kickoff_started"] = "crew_kickoff_started"
 
 
 class CrewKickoffCompletedEvent(CrewBaseEvent):
     """Event emitted when a crew completes execution"""
 
     output: Any
-    type: str = "crew_kickoff_completed"
+    type: Literal["crew_kickoff_completed"] = "crew_kickoff_completed"
     total_tokens: int = 0
 
 
@@ -55,7 +55,7 @@ class CrewKickoffFailedEvent(CrewBaseEvent):
     """Event emitted when a crew fails to complete execution"""
 
     error: str
-    type: str = "crew_kickoff_failed"
+    type: Literal["crew_kickoff_failed"] = "crew_kickoff_failed"
 
 
 class CrewTrainStartedEvent(CrewBaseEvent):
@@ -64,7 +64,7 @@ class CrewTrainStartedEvent(CrewBaseEvent):
     n_iterations: int
     filename: str
     inputs: dict[str, Any] | None
-    type: str = "crew_train_started"
+    type: Literal["crew_train_started"] = "crew_train_started"
 
 
 class CrewTrainCompletedEvent(CrewBaseEvent):
@@ -72,14 +72,14 @@ class CrewTrainCompletedEvent(CrewBaseEvent):
 
     n_iterations: int
     filename: str
-    type: str = "crew_train_completed"
+    type: Literal["crew_train_completed"] = "crew_train_completed"
 
 
 class CrewTrainFailedEvent(CrewBaseEvent):
     """Event emitted when a crew fails to complete training"""
 
     error: str
-    type: str = "crew_train_failed"
+    type: Literal["crew_train_failed"] = "crew_train_failed"
 
 
 class CrewTestStartedEvent(CrewBaseEvent):
@@ -88,20 +88,20 @@ class CrewTestStartedEvent(CrewBaseEvent):
     n_iterations: int
     eval_llm: str | Any | None
     inputs: dict[str, Any] | None
-    type: str = "crew_test_started"
+    type: Literal["crew_test_started"] = "crew_test_started"
 
 
 class CrewTestCompletedEvent(CrewBaseEvent):
     """Event emitted when a crew completes testing"""
 
-    type: str = "crew_test_completed"
+    type: Literal["crew_test_completed"] = "crew_test_completed"
 
 
 class CrewTestFailedEvent(CrewBaseEvent):
     """Event emitted when a crew fails to complete testing"""
 
     error: str
-    type: str = "crew_test_failed"
+    type: Literal["crew_test_failed"] = "crew_test_failed"
 
 
 class CrewTestResultEvent(CrewBaseEvent):
@@ -110,4 +110,4 @@ class CrewTestResultEvent(CrewBaseEvent):
     quality: float
     execution_duration: float
     model: str
-    type: str = "crew_test_result"
+    type: Literal["crew_test_result"] = "crew_test_result"

lib/crewai/src/crewai/events/types/flow_events.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Literal
 
 from pydantic import BaseModel, ConfigDict
 
@@ -17,14 +17,14 @@ class FlowStartedEvent(FlowEvent):
 
     flow_name: str
     inputs: dict[str, Any] | None = None
-    type: str = "flow_started"
+    type: Literal["flow_started"] = "flow_started"
 
 
 class FlowCreatedEvent(FlowEvent):
     """Event emitted when a flow is created"""
 
     flow_name: str
-    type: str = "flow_created"
+    type: Literal["flow_created"] = "flow_created"
 
 
 class MethodExecutionStartedEvent(FlowEvent):
@@ -34,7 +34,7 @@ class MethodExecutionStartedEvent(FlowEvent):
     method_name: str
     state: dict[str, Any] | BaseModel
     params: dict[str, Any] | None = None
-    type: str = "method_execution_started"
+    type: Literal["method_execution_started"] = "method_execution_started"
 
 
 class MethodExecutionFinishedEvent(FlowEvent):
@@ -44,7 +44,7 @@ class MethodExecutionFinishedEvent(FlowEvent):
     method_name: str
     result: Any = None
     state: dict[str, Any] | BaseModel
-    type: str = "method_execution_finished"
+    type: Literal["method_execution_finished"] = "method_execution_finished"
 
 
 class MethodExecutionFailedEvent(FlowEvent):
@@ -53,7 +53,7 @@ class MethodExecutionFailedEvent(FlowEvent):
     flow_name: str
     method_name: str
     error: Exception
-    type: str = "method_execution_failed"
+    type: Literal["method_execution_failed"] = "method_execution_failed"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
@@ -78,7 +78,7 @@ class MethodExecutionPausedEvent(FlowEvent):
     flow_id: str
     message: str
     emit: list[str] | None = None
-    type: str = "method_execution_paused"
+    type: Literal["method_execution_paused"] = "method_execution_paused"
 
 
 class FlowFinishedEvent(FlowEvent):
@@ -86,7 +86,7 @@ class FlowFinishedEvent(FlowEvent):
 
     flow_name: str
     result: Any | None = None
-    type: str = "flow_finished"
+    type: Literal["flow_finished"] = "flow_finished"
     state: dict[str, Any] | BaseModel
 
 
@@ -110,14 +110,14 @@ class FlowPausedEvent(FlowEvent):
     state: dict[str, Any] | BaseModel
     message: str
     emit: list[str] | None = None
-    type: str = "flow_paused"
+    type: Literal["flow_paused"] = "flow_paused"
 
 
 class FlowPlotEvent(FlowEvent):
     """Event emitted when a flow plot is created"""
 
     flow_name: str
-    type: str = "flow_plot"
+    type: Literal["flow_plot"] = "flow_plot"
 
 
 class HumanFeedbackRequestedEvent(FlowEvent):
@@ -138,7 +138,7 @@ class HumanFeedbackRequestedEvent(FlowEvent):
     output: Any
     message: str
     emit: list[str] | None = None
-    type: str = "human_feedback_requested"
+    type: Literal["human_feedback_requested"] = "human_feedback_requested"
 
 
 class HumanFeedbackReceivedEvent(FlowEvent):
@@ -157,4 +157,4 @@ class HumanFeedbackReceivedEvent(FlowEvent):
     method_name: str
     feedback: str
     outcome: str | None = None
-    type: str = "human_feedback_received"
+    type: Literal["human_feedback_received"] = "human_feedback_received"

lib/crewai/src/crewai/events/types/knowledge_events.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -20,14 +20,14 @@ class KnowledgeEventBase(BaseEvent):
 class KnowledgeRetrievalStartedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge retrieval is started."""
 
-    type: str = "knowledge_search_query_started"
+    type: Literal["knowledge_search_query_started"] = "knowledge_search_query_started"
 
 
 class KnowledgeRetrievalCompletedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge retrieval is completed."""
 
     query: str
-    type: str = "knowledge_search_query_completed"
+    type: Literal["knowledge_search_query_completed"] = "knowledge_search_query_completed"
     retrieved_knowledge: str
 
 
@@ -35,13 +35,13 @@ class KnowledgeQueryStartedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge query is started."""
 
     task_prompt: str
-    type: str = "knowledge_query_started"
+    type: Literal["knowledge_query_started"] = "knowledge_query_started"
 
 
 class KnowledgeQueryFailedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge query fails."""
 
-    type: str = "knowledge_query_failed"
+    type: Literal["knowledge_query_failed"] = "knowledge_query_failed"
     error: str
 
 
@@ -49,12 +49,12 @@ class KnowledgeQueryCompletedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge query is completed."""
 
     query: str
-    type: str = "knowledge_query_completed"
+    type: Literal["knowledge_query_completed"] = "knowledge_query_completed"
 
 
 class KnowledgeSearchQueryFailedEvent(KnowledgeEventBase):
     """Event emitted when a knowledge search query fails."""
 
     query: str
-    type: str = "knowledge_search_query_failed"
+    type: Literal["knowledge_search_query_failed"] = "knowledge_search_query_failed"
     error: str

lib/crewai/src/crewai/events/types/llm_events.py

@@ -1,5 +1,5 @@
 from enum import Enum
-from typing import Any
+from typing import Any, Literal
 
 from pydantic import BaseModel
 
@@ -42,7 +42,7 @@ class LLMCallStartedEvent(LLMEventBase):
             multimodal content (text, images, etc.)
     """
 
-    type: str = "llm_call_started"
+    type: Literal["llm_call_started"] = "llm_call_started"
     messages: str | list[dict[str, Any]] | None = None
     tools: list[dict[str, Any]] | None = None
     callbacks: list[Any] | None = None
@@ -52,7 +52,7 @@ class LLMCallStartedEvent(LLMEventBase):
 class LLMCallCompletedEvent(LLMEventBase):
     """Event emitted when a LLM call completes"""
 
-    type: str = "llm_call_completed"
+    type: Literal["llm_call_completed"] = "llm_call_completed"
     messages: str | list[dict[str, Any]] | None = None
     response: Any
     call_type: LLMCallType
@@ -62,7 +62,7 @@ class LLMCallFailedEvent(LLMEventBase):
     """Event emitted when a LLM call fails"""
 
     error: str
-    type: str = "llm_call_failed"
+    type: Literal["llm_call_failed"] = "llm_call_failed"
 
 
 class FunctionCall(BaseModel):
@@ -80,7 +80,7 @@ class ToolCall(BaseModel):
 class LLMStreamChunkEvent(LLMEventBase):
     """Event emitted when a streaming chunk is received"""
 
-    type: str = "llm_stream_chunk"
+    type: Literal["llm_stream_chunk"] = "llm_stream_chunk"
     chunk: str
     tool_call: ToolCall | None = None
     call_type: LLMCallType | None = None

lib/crewai/src/crewai/events/types/llm_guardrail_events.py

@@ -1,6 +1,6 @@
 from collections.abc import Callable
 from inspect import getsource
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -27,7 +27,7 @@ class LLMGuardrailStartedEvent(LLMGuardrailBaseEvent):
         retry_count: The number of times the guardrail has been retried
     """
 
-    type: str = "llm_guardrail_started"
+    type: Literal["llm_guardrail_started"] = "llm_guardrail_started"
     guardrail: str | Callable
     retry_count: int
 
@@ -53,7 +53,7 @@ class LLMGuardrailCompletedEvent(LLMGuardrailBaseEvent):
         retry_count: The number of times the guardrail has been retried
     """
 
-    type: str = "llm_guardrail_completed"
+    type: Literal["llm_guardrail_completed"] = "llm_guardrail_completed"
     success: bool
     result: Any
     error: str | None = None
@@ -68,6 +68,6 @@ class LLMGuardrailFailedEvent(LLMGuardrailBaseEvent):
         retry_count: The number of times the guardrail has been retried
     """
 
-    type: str = "llm_guardrail_failed"
+    type: Literal["llm_guardrail_failed"] = "llm_guardrail_failed"
     error: str
     retry_count: int

lib/crewai/src/crewai/events/types/logging_events.py

@@ -1,6 +1,6 @@
 """Agent logging events that don't reference BaseAgent to avoid circular imports."""
 
-from typing import Any
+from typing import Any, Literal
 
 from pydantic import ConfigDict
 
@@ -13,7 +13,7 @@ class AgentLogsStartedEvent(BaseEvent):
     agent_role: str
     task_description: str | None = None
     verbose: bool = False
-    type: str = "agent_logs_started"
+    type: Literal["agent_logs_started"] = "agent_logs_started"
 
 
 class AgentLogsExecutionEvent(BaseEvent):
@@ -22,6 +22,6 @@ class AgentLogsExecutionEvent(BaseEvent):
     agent_role: str
     formatted_answer: Any
     verbose: bool = False
-    type: str = "agent_logs_execution"
+    type: Literal["agent_logs_execution"] = "agent_logs_execution"
 
     model_config = ConfigDict(arbitrary_types_allowed=True)

lib/crewai/src/crewai/events/types/mcp_events.py

@@ -1,5 +1,5 @@
 from datetime import datetime
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -24,7 +24,7 @@ class MCPEvent(BaseEvent):
 class MCPConnectionStartedEvent(MCPEvent):
     """Event emitted when starting to connect to an MCP server."""
 
-    type: str = "mcp_connection_started"
+    type: Literal["mcp_connection_started"] = "mcp_connection_started"
     connect_timeout: int | None = None
     is_reconnect: bool = (
         False  # True if this is a reconnection, False for first connection
@@ -34,7 +34,7 @@ class MCPConnectionStartedEvent(MCPEvent):
 class MCPConnectionCompletedEvent(MCPEvent):
     """Event emitted when successfully connected to an MCP server."""
 
-    type: str = "mcp_connection_completed"
+    type: Literal["mcp_connection_completed"] = "mcp_connection_completed"
     started_at: datetime | None = None
     completed_at: datetime | None = None
     connection_duration_ms: float | None = None
@@ -46,7 +46,7 @@ class MCPConnectionCompletedEvent(MCPEvent):
 class MCPConnectionFailedEvent(MCPEvent):
     """Event emitted when connection to an MCP server fails."""
 
-    type: str = "mcp_connection_failed"
+    type: Literal["mcp_connection_failed"] = "mcp_connection_failed"
     error: str
     error_type: str | None = None  # "timeout", "authentication", "network", etc.
     started_at: datetime | None = None
@@ -56,7 +56,7 @@ class MCPConnectionFailedEvent(MCPEvent):
 class MCPToolExecutionStartedEvent(MCPEvent):
     """Event emitted when starting to execute an MCP tool."""
 
-    type: str = "mcp_tool_execution_started"
+    type: Literal["mcp_tool_execution_started"] = "mcp_tool_execution_started"
     tool_name: str
     tool_args: dict[str, Any] | None = None
 
@@ -64,7 +64,7 @@ class MCPToolExecutionStartedEvent(MCPEvent):
 class MCPToolExecutionCompletedEvent(MCPEvent):
     """Event emitted when MCP tool execution completes."""
 
-    type: str = "mcp_tool_execution_completed"
+    type: Literal["mcp_tool_execution_completed"] = "mcp_tool_execution_completed"
     tool_name: str
     tool_args: dict[str, Any] | None = None
     result: Any | None = None
@@ -76,7 +76,7 @@ class MCPToolExecutionCompletedEvent(MCPEvent):
 class MCPToolExecutionFailedEvent(MCPEvent):
     """Event emitted when MCP tool execution fails."""
 
-    type: str = "mcp_tool_execution_failed"
+    type: Literal["mcp_tool_execution_failed"] = "mcp_tool_execution_failed"
     tool_name: str
     tool_args: dict[str, Any] | None = None
     error: str

lib/crewai/src/crewai/events/types/memory_events.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -23,7 +23,7 @@ class MemoryBaseEvent(BaseEvent):
 class MemoryQueryStartedEvent(MemoryBaseEvent):
     """Event emitted when a memory query is started"""
 
-    type: str = "memory_query_started"
+    type: Literal["memory_query_started"] = "memory_query_started"
     query: str
     limit: int
     score_threshold: float | None = None
@@ -32,7 +32,7 @@ class MemoryQueryStartedEvent(MemoryBaseEvent):
 class MemoryQueryCompletedEvent(MemoryBaseEvent):
     """Event emitted when a memory query is completed successfully"""
 
-    type: str = "memory_query_completed"
+    type: Literal["memory_query_completed"] = "memory_query_completed"
     query: str
     results: Any
     limit: int
@@ -43,7 +43,7 @@ class MemoryQueryCompletedEvent(MemoryBaseEvent):
 class MemoryQueryFailedEvent(MemoryBaseEvent):
     """Event emitted when a memory query fails"""
 
-    type: str = "memory_query_failed"
+    type: Literal["memory_query_failed"] = "memory_query_failed"
     query: str
     limit: int
     score_threshold: float | None = None
@@ -53,7 +53,7 @@ class MemoryQueryFailedEvent(MemoryBaseEvent):
 class MemorySaveStartedEvent(MemoryBaseEvent):
     """Event emitted when a memory save operation is started"""
 
-    type: str = "memory_save_started"
+    type: Literal["memory_save_started"] = "memory_save_started"
     value: str | None = None
     metadata: dict[str, Any] | None = None
     agent_role: str | None = None
@@ -62,7 +62,7 @@ class MemorySaveStartedEvent(MemoryBaseEvent):
 class MemorySaveCompletedEvent(MemoryBaseEvent):
     """Event emitted when a memory save operation is completed successfully"""
 
-    type: str = "memory_save_completed"
+    type: Literal["memory_save_completed"] = "memory_save_completed"
     value: str
     metadata: dict[str, Any] | None = None
     agent_role: str | None = None
@@ -72,7 +72,7 @@ class MemorySaveCompletedEvent(MemoryBaseEvent):
 class MemorySaveFailedEvent(MemoryBaseEvent):
     """Event emitted when a memory save operation fails"""
 
-    type: str = "memory_save_failed"
+    type: Literal["memory_save_failed"] = "memory_save_failed"
     value: str | None = None
     metadata: dict[str, Any] | None = None
     agent_role: str | None = None
@@ -82,14 +82,14 @@ class MemorySaveFailedEvent(MemoryBaseEvent):
 class MemoryRetrievalStartedEvent(MemoryBaseEvent):
     """Event emitted when memory retrieval for a task prompt starts"""
 
-    type: str = "memory_retrieval_started"
+    type: Literal["memory_retrieval_started"] = "memory_retrieval_started"
     task_id: str | None = None
 
 
 class MemoryRetrievalCompletedEvent(MemoryBaseEvent):
     """Event emitted when memory retrieval for a task prompt completes successfully"""
 
-    type: str = "memory_retrieval_completed"
+    type: Literal["memory_retrieval_completed"] = "memory_retrieval_completed"
     task_id: str | None = None
     memory_content: str
     retrieval_time_ms: float
@@ -98,6 +98,6 @@ class MemoryRetrievalCompletedEvent(MemoryBaseEvent):
 class MemoryRetrievalFailedEvent(MemoryBaseEvent):
     """Event emitted when memory retrieval for a task prompt fails."""
 
-    type: str = "memory_retrieval_failed"
+    type: Literal["memory_retrieval_failed"] = "memory_retrieval_failed"
     task_id: str | None = None
     error: str

lib/crewai/src/crewai/events/types/reasoning_events.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 
@@ -24,7 +24,7 @@ class ReasoningEvent(BaseEvent):
 class AgentReasoningStartedEvent(ReasoningEvent):
     """Event emitted when an agent starts reasoning about a task."""
 
-    type: str = "agent_reasoning_started"
+    type: Literal["agent_reasoning_started"] = "agent_reasoning_started"
     agent_role: str
     task_id: str
 
@@ -32,7 +32,7 @@ class AgentReasoningStartedEvent(ReasoningEvent):
 class AgentReasoningCompletedEvent(ReasoningEvent):
     """Event emitted when an agent finishes its reasoning process."""
 
-    type: str = "agent_reasoning_completed"
+    type: Literal["agent_reasoning_completed"] = "agent_reasoning_completed"
     agent_role: str
     task_id: str
     plan: str
@@ -42,7 +42,7 @@ class AgentReasoningCompletedEvent(ReasoningEvent):
 class AgentReasoningFailedEvent(ReasoningEvent):
     """Event emitted when the reasoning process fails."""
 
-    type: str = "agent_reasoning_failed"
+    type: Literal["agent_reasoning_failed"] = "agent_reasoning_failed"
     agent_role: str
     task_id: str
     error: str

lib/crewai/src/crewai/events/types/task_events.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Literal
 
 from crewai.events.base_events import BaseEvent
 from crewai.tasks.task_output import TaskOutput
@@ -7,7 +7,7 @@ from crewai.tasks.task_output import TaskOutput
 class TaskStartedEvent(BaseEvent):
     """Event emitted when a task starts"""
 
-    type: str = "task_started"
+    type: Literal["task_started"] = "task_started"
     context: str | None
     task: Any | None = None
 
@@ -28,7 +28,7 @@ class TaskCompletedEvent(BaseEvent):
     """Event emitted when a task completes"""
 
     output: TaskOutput
-    type: str = "task_completed"
+    type: Literal["task_completed"] = "task_completed"
     task: Any | None = None
 
     def __init__(self, **data):
@@ -48,7 +48,7 @@ class TaskFailedEvent(BaseEvent):
     """Event emitted when a task fails"""
 
     error: str
-    type: str = "task_failed"
+    type: Literal["task_failed"] = "task_failed"
     task: Any | None = None
 
     def __init__(self, **data):
@@ -67,7 +67,7 @@ class TaskFailedEvent(BaseEvent):
 class TaskEvaluationEvent(BaseEvent):
     """Event emitted when a task evaluation is completed"""
 
-    type: str = "task_evaluation"
+    type: Literal["task_evaluation"] = "task_evaluation"
     evaluation_type: str
     task: Any | None = None
 

lib/crewai/src/crewai/events/types/tool_usage_events.py

@@ -1,6 +1,6 @@
 from collections.abc import Callable
 from datetime import datetime
-from typing import Any
+from typing import Any, Literal
 
 from pydantic import ConfigDict
 
@@ -55,7 +55,7 @@ class ToolUsageEvent(BaseEvent):
 class ToolUsageStartedEvent(ToolUsageEvent):
     """Event emitted when a tool execution is started"""
 
-    type: str = "tool_usage_started"
+    type: Literal["tool_usage_started"] = "tool_usage_started"
 
 
 class ToolUsageFinishedEvent(ToolUsageEvent):
@@ -65,35 +65,35 @@ class ToolUsageFinishedEvent(ToolUsageEvent):
     finished_at: datetime
     from_cache: bool = False
     output: Any
-    type: str = "tool_usage_finished"
+    type: Literal["tool_usage_finished"] = "tool_usage_finished"
 
 
 class ToolUsageErrorEvent(ToolUsageEvent):
     """Event emitted when a tool execution encounters an error"""
 
     error: Any
-    type: str = "tool_usage_error"
+    type: Literal["tool_usage_error"] = "tool_usage_error"
 
 
 class ToolValidateInputErrorEvent(ToolUsageEvent):
     """Event emitted when a tool input validation encounters an error"""
 
     error: Any
-    type: str = "tool_validate_input_error"
+    type: Literal["tool_validate_input_error"] = "tool_validate_input_error"
 
 
 class ToolSelectionErrorEvent(ToolUsageEvent):
     """Event emitted when a tool selection encounters an error"""
 
     error: Any
-    type: str = "tool_selection_error"
+    type: Literal["tool_selection_error"] = "tool_selection_error"
 
 
 class ToolExecutionErrorEvent(BaseEvent):
     """Event emitted when a tool execution encounters an error"""
 
     error: Any
-    type: str = "tool_execution_error"
+    type: Literal["tool_execution_error"] = "tool_execution_error"
     tool_name: str
     tool_args: dict[str, Any]
     tool_class: Callable

lib/crewai/src/crewai/flow/flow.py

@@ -7,7 +7,7 @@ for building event-driven workflows with conditional execution and routing.
 from __future__ import annotations
 
 import asyncio
-from collections.abc import Callable, Sequence
+from collections.abc import Callable
 from concurrent.futures import Future
 import copy
 import inspect
@@ -2382,7 +2382,7 @@ class Flow(Generic[T], metaclass=FlowMeta):
         message: str,
         output: Any,
         metadata: dict[str, Any] | None = None,
-        emit: Sequence[str] | None = None,
+        emit: list[str] | None = None,
     ) -> str:
         """Request feedback from a human.
         Args:
@@ -2453,7 +2453,7 @@ class Flow(Generic[T], metaclass=FlowMeta):
     def _collapse_to_outcome(
         self,
         feedback: str,
-        outcomes: Sequence[str],
+        outcomes: list[str],
         llm: str | BaseLLM,
     ) -> str:
         """Collapse free-form feedback to a predefined outcome using LLM.

lib/crewai/src/crewai/flow/human_feedback.py

@@ -53,7 +53,7 @@ Example (asynchronous with custom provider):
 from __future__ import annotations
 
 import asyncio
-from collections.abc import Callable, Sequence
+from collections.abc import Callable
 from dataclasses import dataclass, field
 from datetime import datetime
 from functools import wraps
@@ -128,7 +128,7 @@ class HumanFeedbackConfig:
     """
 
     message: str
-    emit: Sequence[str] | None = None
+    emit: list[str] | None = None
     llm: str | BaseLLM | None = None
     default_outcome: str | None = None
     metadata: dict[str, Any] | None = None
@@ -154,7 +154,7 @@ class HumanFeedbackMethod(FlowMethod[Any, Any]):
 
 def human_feedback(
     message: str,
-    emit: Sequence[str] | None = None,
+    emit: list[str] | None = None,
     llm: str | BaseLLM | None = None,
     default_outcome: str | None = None,
     metadata: dict[str, Any] | None = None,

lib/crewai/src/crewai/llms/base_llm.py

@@ -404,7 +404,7 @@ class BaseLLM(ABC):
         from_agent: Agent | None = None,
         tool_call: dict[str, Any] | None = None,
         call_type: LLMCallType | None = None,
-        response_id: str | None = None
+        response_id: str | None = None,
     ) -> None:
         """Emit stream chunk event.
 
@@ -427,7 +427,7 @@ class BaseLLM(ABC):
                 from_task=from_task,
                 from_agent=from_agent,
                 call_type=call_type,
-                response_id=response_id
+                response_id=response_id,
             ),
         )
 
@@ -620,13 +620,11 @@ class BaseLLM(ABC):
         try:
             # Try to parse as JSON first
             if response.strip().startswith("{") or response.strip().startswith("["):
-                data = json.loads(response)
+                return response_format.model_validate_json(response)
-                return response_format.model_validate(data)
 
             json_match = _JSON_EXTRACTION_PATTERN.search(response)
             if json_match:
-                data = json.loads(json_match.group())
+                return response_format.model_validate_json(json_match.group())
-                return response_format.model_validate(data)
 
             raise ValueError("No JSON found in response")
 

lib/crewai/src/crewai/llms/providers/bedrock/completion.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from collections.abc import Mapping, Sequence
+from collections.abc import Sequence
 from contextlib import AsyncExitStack
 import json
 import logging
@@ -538,7 +538,7 @@ class BedrockCompletion(BaseLLM):
         self,
         messages: list[LLMMessage],
         body: BedrockConverseRequestBody,
-        available_functions: Mapping[str, Any] | None = None,
+        available_functions: dict[str, Any] | None = None,
         from_task: Any | None = None,
         from_agent: Any | None = None,
         response_model: type[BaseModel] | None = None,
@@ -1009,7 +1009,7 @@ class BedrockCompletion(BaseLLM):
         self,
         messages: list[LLMMessage],
         body: BedrockConverseRequestBody,
-        available_functions: Mapping[str, Any] | None = None,
+        available_functions: dict[str, Any] | None = None,
         from_task: Any | None = None,
         from_agent: Any | None = None,
         response_model: type[BaseModel] | None = None,

lib/crewai/src/crewai/rag/chromadb/types.py

@@ -1,6 +1,5 @@
 """Type definitions specific to ChromaDB implementation."""
 
-from collections.abc import Mapping
 from typing import Any, NamedTuple
 
 from chromadb.api import AsyncClientAPI, ClientAPI
@@ -49,7 +48,7 @@ class PreparedDocuments(NamedTuple):
 
     ids: list[str]
     texts: list[str]
-    metadatas: list[Mapping[str, str | int | float | bool]]
+    metadatas: list[dict[str, str | int | float | bool]]
 
 
 class ExtractedSearchParams(NamedTuple):

lib/crewai/src/crewai/rag/chromadb/utils.py

@@ -1,6 +1,5 @@
 """Utility functions for ChromaDB client implementation."""
 
-from collections.abc import Mapping
 import hashlib
 import json
 from typing import Literal, TypeGuard, cast
@@ -66,7 +65,7 @@ def _prepare_documents_for_chromadb(
     """
     ids: list[str] = []
     texts: list[str] = []
-    metadatas: list[Mapping[str, str | int | float | bool]] = []
+    metadatas: list[dict[str, str | int | float | bool]] = []
     seen_ids: dict[str, int] = {}
 
     try:
@@ -111,7 +110,7 @@ def _prepare_documents_for_chromadb(
 
 def _create_batch_slice(
     prepared: PreparedDocuments, start_index: int, batch_size: int
-) -> tuple[list[str], list[str], list[Mapping[str, str | int | float | bool]] | None]:
+) -> tuple[list[str], list[str], list[dict[str, str | int | float | bool]] | None]:
     """Create a batch slice from prepared documents.
 
     Args:

lib/crewai/src/crewai/rag/embeddings/types.py

@@ -1,6 +1,8 @@
 """Type definitions for the embeddings module."""
 
-from typing import Any, Literal, TypeAlias
+from typing import Annotated, Any, Literal, TypeAlias
+
+from pydantic import Field
 
 from crewai.rag.core.base_embeddings_provider import BaseEmbeddingsProvider
 from crewai.rag.embeddings.providers.aws.types import BedrockProviderSpec
@@ -29,7 +31,7 @@ from crewai.rag.embeddings.providers.text2vec.types import Text2VecProviderSpec
 from crewai.rag.embeddings.providers.voyageai.types import VoyageAIProviderSpec
 
 
-ProviderSpec: TypeAlias = (
+ProviderSpec: TypeAlias = Annotated[
     AzureProviderSpec
     | BedrockProviderSpec
     | CohereProviderSpec
@@ -47,8 +49,9 @@ ProviderSpec: TypeAlias = (
     | Text2VecProviderSpec
     | VertexAIProviderSpec
     | VoyageAIProviderSpec
-    | WatsonXProviderSpec
+    | WatsonXProviderSpec,
-)
+    Field(discriminator="provider"),
+]
 
 AllowedEmbeddingProviders = Literal[
     "azure",

lib/crewai/src/crewai/rag/types.py

@@ -1,6 +1,6 @@
 """Type definitions for RAG (Retrieval-Augmented Generation) systems."""
 
-from collections.abc import Callable, Mapping
+from collections.abc import Callable
 from typing import Any, TypeAlias
 
 from typing_extensions import Required, TypedDict
@@ -19,8 +19,8 @@ class BaseRecord(TypedDict, total=False):
     doc_id: str
     content: Required[str]
     metadata: (
-        Mapping[str, str | int | float | bool]
+        dict[str, str | int | float | bool]
-        | list[Mapping[str, str | int | float | bool]]
+        | list[dict[str, str | int | float | bool]]
     )
 
 

lib/crewai/src/crewai/tools/structured_tool.py

@@ -200,9 +200,12 @@ class CrewStructuredTool:
         """
         if isinstance(raw_args, str):
             try:
-                raw_args = json.loads(raw_args)
+                validated_args = self.args_schema.model_validate_json(raw_args)
+                return validated_args.model_dump()
             except json.JSONDecodeError as e:
                 raise ValueError(f"Failed to parse arguments as JSON: {e}") from e
+            except Exception as e:
+                raise ValueError(f"Arguments validation failed: {e}") from e
 
         try:
             validated_args = self.args_schema.model_validate(raw_args)

lib/crewai/src/crewai/utilities/agent_utils.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import asyncio
-from collections.abc import Callable, Sequence
+from collections.abc import Callable
 import json
 import re
 from typing import TYPE_CHECKING, Any, Final, Literal, TypedDict
@@ -98,7 +98,7 @@ def parse_tools(tools: list[BaseTool]) -> list[CrewStructuredTool]:
     return tools_list
 
 
-def get_tool_names(tools: Sequence[CrewStructuredTool | BaseTool]) -> str:
+def get_tool_names(tools: list[CrewStructuredTool | BaseTool]) -> str:
     """Get the sanitized names of the tools.
 
     Args:
@@ -111,7 +111,7 @@ def get_tool_names(tools: Sequence[CrewStructuredTool | BaseTool]) -> str:
 
 
 def render_text_description_and_args(
-    tools: Sequence[CrewStructuredTool | BaseTool],
+    tools: list[CrewStructuredTool | BaseTool],
 ) -> str:
     """Render the tool name, description, and args in plain text.
 
@@ -130,7 +130,7 @@ def render_text_description_and_args(
 
 
 def convert_tools_to_openai_schema(
-    tools: Sequence[BaseTool | CrewStructuredTool],
+    tools: list[BaseTool | CrewStructuredTool],
 ) -> tuple[list[dict[str, Any]], dict[str, Callable[..., Any]]]:
     """Convert CrewAI tools to OpenAI function calling format.