docs translations

Merge branch 'main' of github.com:crewAIInc/crewAI into lorenze/fix-google-vertex-api-using-api-keys
docs update here
2026-01-17 03:58:33 +00:00 · 2026-01-15 14:43:43 -08:00 · 2026-01-15 14:37:37 -08:00 · 2026-01-15 14:37:16 -08:00 · 2026-01-15 14:34:07 -08:00
20 changed files with 440 additions and 1811 deletions
--- a/docs/en/concepts/llms.mdx
+++ b/docs/en/concepts/llms.mdx
@@ -375,10 +375,13 @@ In this section, you'll find detailed examples that help you select, configure,
    GOOGLE_API_KEY=<your-api-key>
    GEMINI_API_KEY=<your-api-key>

-    # Optional - for Vertex AI
+    # For Vertex AI Express mode (API key authentication)
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+
+    # For Vertex AI with service account
    GOOGLE_CLOUD_PROJECT=<your-project-id>
    GOOGLE_CLOUD_LOCATION=<location>  # Defaults to us-central1
-    GOOGLE_GENAI_USE_VERTEXAI=true  # Set to use Vertex AI
    ```

    **Basic Usage:**
@@ -412,7 +415,35 @@ In this section, you'll find detailed examples that help you select, configure,
    )
    ```

-    **Vertex AI Configuration:**
+    **Vertex AI Express Mode (API Key Authentication):**
+
+    Vertex AI Express mode allows you to use Vertex AI with simple API key authentication instead of service account credentials. This is the quickest way to get started with Vertex AI.
+
+    To enable Express mode, set both environment variables in your `.env` file:
+    ```toml .env
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+    ```
+
+    Then use the LLM as usual:
+    ```python Code
+    from crewai import LLM
+
+    llm = LLM(
+        model="gemini/gemini-2.0-flash",
+        temperature=0.7
+    )
+    ```
+
+    <Info>
+      To get an Express mode API key:
+      - New Google Cloud users: Get an [express mode API key](https://cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey)
+      - Existing Google Cloud users: Get a [Google Cloud API key bound to a service account](https://cloud.google.com/docs/authentication/api-keys)
+      
+      For more details, see the [Vertex AI Express mode documentation](https://docs.cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey).
+    </Info>
+
+    **Vertex AI Configuration (Service Account):**
    ```python Code
    from crewai import LLM

@@ -424,10 +455,10 @@ In this section, you'll find detailed examples that help you select, configure,
    ```

    **Supported Environment Variables:**
-    - `GOOGLE_API_KEY` or `GEMINI_API_KEY`: Your Google API key (required for Gemini API)
-    - `GOOGLE_CLOUD_PROJECT`: Google Cloud project ID (for Vertex AI)
+    - `GOOGLE_API_KEY` or `GEMINI_API_KEY`: Your Google API key (required for Gemini API and Vertex AI Express mode)
+    - `GOOGLE_GENAI_USE_VERTEXAI`: Set to `true` to use Vertex AI (required for Express mode)
+    - `GOOGLE_CLOUD_PROJECT`: Google Cloud project ID (for Vertex AI with service account)
    - `GOOGLE_CLOUD_LOCATION`: GCP location (defaults to `us-central1`)
-    - `GOOGLE_GENAI_USE_VERTEXAI`: Set to `true` to use Vertex AI

    **Features:**
    - Native function calling support for Gemini 1.5+ and 2.x models
--- a/docs/ko/concepts/llms.mdx
+++ b/docs/ko/concepts/llms.mdx
@@ -107,7 +107,7 @@ CrewAI 코드 내에는 사용할 모델을 지정할 수 있는 여러 위치

 ## 공급자 구성 예시

-CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양한 LLM 공급자를 지원합니다.  
+CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양한 LLM 공급자를 지원합니다.
 이 섹션에서는 프로젝트의 요구에 가장 적합한 LLM을 선택, 구성, 최적화하는 데 도움이 되는 자세한 예시를 제공합니다.

 <AccordionGroup>
@@ -153,8 +153,8 @@ CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양
  </Accordion>

  <Accordion title="Meta-Llama">
-    Meta의 Llama API는 Meta의 대형 언어 모델 패밀리 접근을 제공합니다.  
-    API는 [Meta Llama API](https://llama.developer.meta.com?utm_source=partner-crewai&utm_medium=website)에서 사용할 수 있습니다.  
+    Meta의 Llama API는 Meta의 대형 언어 모델 패밀리 접근을 제공합니다.
+    API는 [Meta Llama API](https://llama.developer.meta.com?utm_source=partner-crewai&utm_medium=website)에서 사용할 수 있습니다.
    `.env` 파일에 다음 환경 변수를 설정하십시오:

    ```toml Code
@@ -207,11 +207,20 @@ CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양
    `.env` 파일에 API 키를 설정하십시오. 키가 필요하거나 기존 키를 찾으려면 [AI Studio](https://aistudio.google.com/apikey)를 확인하세요.

    ```toml .env
-    # https://ai.google.dev/gemini-api/docs/api-key
+    # Gemini API 사용 시 (다음 중 하나)
+    GOOGLE_API_KEY=<your-api-key>
    GEMINI_API_KEY=<your-api-key>
+
+    # Vertex AI Express 모드 사용 시 (API 키 인증)
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+
+    # Vertex AI 서비스 계정 사용 시
+    GOOGLE_CLOUD_PROJECT=<your-project-id>
+    GOOGLE_CLOUD_LOCATION=<location>  # 기본값: us-central1
    ```

-    CrewAI 프로젝트에서의 예시 사용법:
+    **기본 사용법:**
    ```python Code
    from crewai import LLM

@@ -221,6 +230,34 @@ CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양
    )
    ```

+    **Vertex AI Express 모드 (API 키 인증):**
+
+    Vertex AI Express 모드를 사용하면 서비스 계정 자격 증명 대신 간단한 API 키 인증으로 Vertex AI를 사용할 수 있습니다. Vertex AI를 시작하는 가장 빠른 방법입니다.
+
+    Express 모드를 활성화하려면 `.env` 파일에 두 환경 변수를 모두 설정하세요:
+    ```toml .env
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+    ```
+
+    그런 다음 평소처럼 LLM을 사용하세요:
+    ```python Code
+    from crewai import LLM
+
+    llm = LLM(
+        model="gemini/gemini-2.0-flash",
+        temperature=0.7
+    )
+    ```
+
+    <Info>
+      Express 모드 API 키를 받으려면:
+      - 신규 Google Cloud 사용자: [Express 모드 API 키](https://cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey) 받기
+      - 기존 Google Cloud 사용자: [서비스 계정에 바인딩된 Google Cloud API 키](https://cloud.google.com/docs/authentication/api-keys) 받기
+
+      자세한 내용은 [Vertex AI Express 모드 문서](https://docs.cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey)를 참조하세요.
+    </Info>
+
    ### Gemini 모델

    Google은 다양한 용도에 최적화된 강력한 모델을 제공합니다.
@@ -476,7 +513,7 @@ CrewAI는 고유한 기능, 인증 방법, 모델 역량을 제공하는 다양

  <Accordion title="Local NVIDIA NIM Deployed using WSL2">

-    NVIDIA NIM을 이용하면 Windows 기기에서 WSL2(Windows Subsystem for Linux)를 통해 강력한 LLM을 로컬로 실행할 수 있습니다.  
+    NVIDIA NIM을 이용하면 Windows 기기에서 WSL2(Windows Subsystem for Linux)를 통해 강력한 LLM을 로컬로 실행할 수 있습니다.
    이 방식은 Nvidia GPU를 활용하여 프라이빗하고, 안전하며, 비용 효율적인 AI 추론을 클라우드 서비스에 의존하지 않고 구현할 수 있습니다.
    데이터 프라이버시, 오프라인 기능이 필요한 개발, 테스트, 또는 프로덕션 환경에 최적입니다.

@@ -954,4 +991,4 @@ LLM 설정을 최대한 활용하는 방법을 알아보세요:
    llm = LLM(model="openai/gpt-4o")  # 128K tokens
    ```
  </Tab>
-</Tabs>
+</Tabs>
--- a/docs/pt-BR/concepts/llms.mdx
+++ b/docs/pt-BR/concepts/llms.mdx
@@ -79,7 +79,7 @@ Existem diferentes locais no código do CrewAI onde você pode especificar o mod

    # Configuração avançada com parâmetros detalhados
    llm = LLM(
-        model="openai/gpt-4", 
+        model="openai/gpt-4",
        temperature=0.8,
        max_tokens=150,
        top_p=0.9,
@@ -207,11 +207,20 @@ Nesta seção, você encontrará exemplos detalhados que ajudam a selecionar, co
    Defina sua chave de API no seu arquivo `.env`. Se precisar de uma chave, ou encontrar uma existente, verifique o [AI Studio](https://aistudio.google.com/apikey).

    ```toml .env
-    # https://ai.google.dev/gemini-api/docs/api-key
+    # Para API Gemini (uma das seguintes)
+    GOOGLE_API_KEY=<your-api-key>
    GEMINI_API_KEY=<your-api-key>
+
+    # Para Vertex AI Express mode (autenticação por chave de API)
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+
+    # Para Vertex AI com conta de serviço
+    GOOGLE_CLOUD_PROJECT=<your-project-id>
+    GOOGLE_CLOUD_LOCATION=<location>  # Padrão: us-central1
    ```

-    Exemplo de uso em seu projeto CrewAI:
+    **Uso Básico:**
    ```python Code
    from crewai import LLM

@@ -221,6 +230,34 @@ Nesta seção, você encontrará exemplos detalhados que ajudam a selecionar, co
    )
    ```

+    **Vertex AI Express Mode (Autenticação por Chave de API):**
+
+    O Vertex AI Express mode permite usar o Vertex AI com autenticação simples por chave de API, em vez de credenciais de conta de serviço. Esta é a maneira mais rápida de começar com o Vertex AI.
+
+    Para habilitar o Express mode, defina ambas as variáveis de ambiente no seu arquivo `.env`:
+    ```toml .env
+    GOOGLE_GENAI_USE_VERTEXAI=true
+    GOOGLE_API_KEY=<your-api-key>
+    ```
+
+    Em seguida, use o LLM normalmente:
+    ```python Code
+    from crewai import LLM
+
+    llm = LLM(
+        model="gemini/gemini-2.0-flash",
+        temperature=0.7
+    )
+    ```
+
+    <Info>
+      Para obter uma chave de API do Express mode:
+      - Novos usuários do Google Cloud: Obtenha uma [chave de API do Express mode](https://cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey)
+      - Usuários existentes do Google Cloud: Obtenha uma [chave de API do Google Cloud vinculada a uma conta de serviço](https://cloud.google.com/docs/authentication/api-keys)
+
+      Para mais detalhes, consulte a [documentação do Vertex AI Express mode](https://docs.cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey).
+    </Info>
+
    ### Modelos Gemini

    O Google oferece uma variedade de modelos poderosos otimizados para diferentes casos de uso.
@@ -823,7 +860,7 @@ Saiba como obter o máximo da configuração do seu LLM:
      Lembre-se de monitorar regularmente o uso de tokens e ajustar suas configurações para otimizar custos e desempenho.
    </Info>
  </Accordion>
-  
+
  <Accordion title="Descartar Parâmetros Adicionais">
    O CrewAI usa Litellm internamente para chamadas LLM, permitindo descartar parâmetros adicionais desnecessários para seu caso de uso. Isso pode simplificar seu código e reduzir a complexidade da configuração do LLM.
    Por exemplo, se não precisar enviar o parâmetro <code>stop</code>, basta omiti-lo na chamada do LLM:
@@ -882,4 +919,4 @@ Saiba como obter o máximo da configuração do seu LLM:
    llm = LLM(model="openai/gpt-4o")  # 128K tokens
    ```
  </Tab>
-</Tabs>
+</Tabs>
--- a/lib/crewai/src/crewai/a2a/task_helpers.py
+++ b/lib/crewai/src/crewai/a2a/task_helpers.py
@@ -3,10 +3,9 @@
 from __future__ import annotations

 from collections.abc import AsyncIterator
-from typing import TYPE_CHECKING, Any, TypedDict
+from typing import TYPE_CHECKING, TypedDict
 import uuid

-from a2a.client.errors import A2AClientHTTPError
 from a2a.types import (
    AgentCard,
    Message,
@@ -21,10 +20,7 @@ from a2a.types import (
 from typing_extensions import NotRequired

 from crewai.events.event_bus import crewai_event_bus
-from crewai.events.types.a2a_events import (
-    A2AConnectionErrorEvent,
-    A2AResponseReceivedEvent,
-)
+from crewai.events.types.a2a_events import A2AResponseReceivedEvent


 if TYPE_CHECKING:
@@ -59,8 +55,7 @@ class TaskStateResult(TypedDict):
    history: list[Message]
    result: NotRequired[str]
    error: NotRequired[str]
-    agent_card: NotRequired[dict[str, Any]]
-    a2a_agent_name: NotRequired[str | None]
+    agent_card: NotRequired[AgentCard]


 def extract_task_result_parts(a2a_task: A2ATask) -> list[str]:
@@ -136,69 +131,50 @@ def process_task_state(
    is_multiturn: bool,
    agent_role: str | None,
    result_parts: list[str] | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    is_final: bool = True,
 ) -> TaskStateResult | None:
    """Process A2A task state and return result dictionary.

    Shared logic for both polling and streaming handlers.

    Args:
-        a2a_task: The A2A task to process.
-        new_messages: List to collect messages (modified in place).
-        agent_card: The agent card.
-        turn_number: Current turn number.
-        is_multiturn: Whether multi-turn conversation.
-        agent_role: Agent role for logging.
+        a2a_task: The A2A task to process
+        new_messages: List to collect messages (modified in place)
+        agent_card: The agent card
+        turn_number: Current turn number
+        is_multiturn: Whether multi-turn conversation
+        agent_role: Agent role for logging
        result_parts: Accumulated result parts (streaming passes accumulated,
-            polling passes None to extract from task).
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        from_task: Optional CrewAI Task for event metadata.
-        from_agent: Optional CrewAI Agent for event metadata.
-        is_final: Whether this is the final response in the stream.
+            polling passes None to extract from task)

    Returns:
-        Result dictionary if terminal/actionable state, None otherwise.
+        Result dictionary if terminal/actionable state, None otherwise
    """
+    should_extract = result_parts is None
    if result_parts is None:
        result_parts = []

    if a2a_task.status.state == TaskState.completed:
-        if not result_parts:
+        if should_extract:
            extracted_parts = extract_task_result_parts(a2a_task)
            result_parts.extend(extracted_parts)
        if a2a_task.history:
            new_messages.extend(a2a_task.history)

        response_text = " ".join(result_parts) if result_parts else ""
-        message_id = None
-        if a2a_task.status and a2a_task.status.message:
-            message_id = a2a_task.status.message.message_id
        crewai_event_bus.emit(
            None,
            A2AResponseReceivedEvent(
                response=response_text,
                turn_number=turn_number,
-                context_id=a2a_task.context_id,
-                message_id=message_id,
                is_multiturn=is_multiturn,
                status="completed",
-                final=is_final,
                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            ),
        )

        return TaskStateResult(
            status=TaskState.completed,
-            agent_card=agent_card.model_dump(exclude_none=True),
+            agent_card=agent_card,
            result=response_text,
            history=new_messages,
        )
@@ -218,24 +194,14 @@ def process_task_state(
            )
            new_messages.append(agent_message)

-        input_message_id = None
-        if a2a_task.status and a2a_task.status.message:
-            input_message_id = a2a_task.status.message.message_id
        crewai_event_bus.emit(
            None,
            A2AResponseReceivedEvent(
                response=response_text,
                turn_number=turn_number,
-                context_id=a2a_task.context_id,
-                message_id=input_message_id,
                is_multiturn=is_multiturn,
                status="input_required",
-                final=is_final,
                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            ),
        )

@@ -243,7 +209,7 @@ def process_task_state(
            status=TaskState.input_required,
            error=response_text,
            history=new_messages,
-            agent_card=agent_card.model_dump(exclude_none=True),
+            agent_card=agent_card,
        )

    if a2a_task.status.state in {TaskState.failed, TaskState.rejected}:
@@ -282,11 +248,6 @@ async def send_message_and_get_task_id(
    turn_number: int,
    is_multiturn: bool,
    agent_role: str | None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    context_id: str | None = None,
 ) -> str | TaskStateResult:
    """Send message and process initial response.

@@ -301,11 +262,6 @@ async def send_message_and_get_task_id(
        turn_number: Current turn number
        is_multiturn: Whether multi-turn conversation
        agent_role: Agent role for logging
-        from_task: Optional CrewAI Task object for event metadata.
-        from_agent: Optional CrewAI Agent object for event metadata.
-        endpoint: Optional A2A endpoint URL.
-        a2a_agent_name: Optional A2A agent name.
-        context_id: Optional A2A context ID for correlation.

    Returns:
        Task ID string if agent needs polling/waiting, or TaskStateResult if done.
@@ -324,16 +280,9 @@ async def send_message_and_get_task_id(
                    A2AResponseReceivedEvent(
                        response=response_text,
                        turn_number=turn_number,
-                        context_id=event.context_id,
-                        message_id=event.message_id,
                        is_multiturn=is_multiturn,
                        status="completed",
-                        final=True,
                        agent_role=agent_role,
-                        endpoint=endpoint,
-                        a2a_agent_name=a2a_agent_name,
-                        from_task=from_task,
-                        from_agent=from_agent,
                    ),
                )

@@ -341,7 +290,7 @@ async def send_message_and_get_task_id(
                    status=TaskState.completed,
                    result=response_text,
                    history=new_messages,
-                    agent_card=agent_card.model_dump(exclude_none=True),
+                    agent_card=agent_card,
                )

            if isinstance(event, tuple):
@@ -355,10 +304,6 @@ async def send_message_and_get_task_id(
                        turn_number=turn_number,
                        is_multiturn=is_multiturn,
                        agent_role=agent_role,
-                        endpoint=endpoint,
-                        a2a_agent_name=a2a_agent_name,
-                        from_task=from_task,
-                        from_agent=from_agent,
                    )
                    if result:
                        return result
@@ -371,99 +316,6 @@ async def send_message_and_get_task_id(
            history=new_messages,
        )

-    except A2AClientHTTPError as e:
-        error_msg = f"HTTP Error {e.status_code}: {e!s}"
-
-        error_message = Message(
-            role=Role.agent,
-            message_id=str(uuid.uuid4()),
-            parts=[Part(root=TextPart(text=error_msg))],
-            context_id=context_id,
-        )
-        new_messages.append(error_message)
-
-        crewai_event_bus.emit(
-            None,
-            A2AConnectionErrorEvent(
-                endpoint=endpoint or "",
-                error=str(e),
-                error_type="http_error",
-                status_code=e.status_code,
-                a2a_agent_name=a2a_agent_name,
-                operation="send_message",
-                context_id=context_id,
-                from_task=from_task,
-                from_agent=from_agent,
-            ),
-        )
-        crewai_event_bus.emit(
-            None,
-            A2AResponseReceivedEvent(
-                response=error_msg,
-                turn_number=turn_number,
-                context_id=context_id,
-                is_multiturn=is_multiturn,
-                status="failed",
-                final=True,
-                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
-            ),
-        )
-        return TaskStateResult(
-            status=TaskState.failed,
-            error=error_msg,
-            history=new_messages,
-        )
-
-    except Exception as e:
-        error_msg = f"Unexpected error during send_message: {e!s}"
-
-        error_message = Message(
-            role=Role.agent,
-            message_id=str(uuid.uuid4()),
-            parts=[Part(root=TextPart(text=error_msg))],
-            context_id=context_id,
-        )
-        new_messages.append(error_message)
-
-        crewai_event_bus.emit(
-            None,
-            A2AConnectionErrorEvent(
-                endpoint=endpoint or "",
-                error=str(e),
-                error_type="unexpected_error",
-                a2a_agent_name=a2a_agent_name,
-                operation="send_message",
-                context_id=context_id,
-                from_task=from_task,
-                from_agent=from_agent,
-            ),
-        )
-        crewai_event_bus.emit(
-            None,
-            A2AResponseReceivedEvent(
-                response=error_msg,
-                turn_number=turn_number,
-                context_id=context_id,
-                is_multiturn=is_multiturn,
-                status="failed",
-                final=True,
-                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
-            ),
-        )
-        return TaskStateResult(
-            status=TaskState.failed,
-            error=error_msg,
-            history=new_messages,
-        )
-
    finally:
        aclose = getattr(event_stream, "aclose", None)
        if aclose:
--- a/lib/crewai/src/crewai/a2a/updates/base.py
+++ b/lib/crewai/src/crewai/a2a/updates/base.py
@@ -22,13 +22,6 @@ class BaseHandlerKwargs(TypedDict, total=False):
    turn_number: int
    is_multiturn: bool
    agent_role: str | None
-    context_id: str | None
-    task_id: str | None
-    endpoint: str | None
-    agent_branch: Any
-    a2a_agent_name: str | None
-    from_task: Any
-    from_agent: Any


 class PollingHandlerKwargs(BaseHandlerKwargs, total=False):
@@ -36,6 +29,8 @@ class PollingHandlerKwargs(BaseHandlerKwargs, total=False):

    polling_interval: float
    polling_timeout: float
+    endpoint: str
+    agent_branch: Any
    history_length: int
    max_polls: int | None

@@ -43,6 +38,9 @@ class PollingHandlerKwargs(BaseHandlerKwargs, total=False):
 class StreamingHandlerKwargs(BaseHandlerKwargs, total=False):
    """Kwargs for streaming handler."""

+    context_id: str | None
+    task_id: str | None
+

 class PushNotificationHandlerKwargs(BaseHandlerKwargs, total=False):
    """Kwargs for push notification handler."""
@@ -51,6 +49,7 @@ class PushNotificationHandlerKwargs(BaseHandlerKwargs, total=False):
    result_store: PushNotificationResultStore
    polling_timeout: float
    polling_interval: float
+    agent_branch: Any


 class PushNotificationResultStore(Protocol):
--- a/lib/crewai/src/crewai/a2a/updates/polling/handler.py
+++ b/lib/crewai/src/crewai/a2a/updates/polling/handler.py
@@ -31,7 +31,6 @@ from crewai.a2a.task_helpers import (
 from crewai.a2a.updates.base import PollingHandlerKwargs
 from crewai.events.event_bus import crewai_event_bus
 from crewai.events.types.a2a_events import (
-    A2AConnectionErrorEvent,
    A2APollingStartedEvent,
    A2APollingStatusEvent,
    A2AResponseReceivedEvent,
@@ -50,33 +49,23 @@ async def _poll_task_until_complete(
    agent_branch: Any | None = None,
    history_length: int = 100,
    max_polls: int | None = None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    context_id: str | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
 ) -> A2ATask:
    """Poll task status until terminal state reached.

    Args:
-        client: A2A client instance.
-        task_id: Task ID to poll.
-        polling_interval: Seconds between poll attempts.
-        polling_timeout: Max seconds before timeout.
-        agent_branch: Agent tree branch for logging.
-        history_length: Number of messages to retrieve per poll.
-        max_polls: Max number of poll attempts (None = unlimited).
-        from_task: Optional CrewAI Task object for event metadata.
-        from_agent: Optional CrewAI Agent object for event metadata.
-        context_id: A2A context ID for correlation.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
+        client: A2A client instance
+        task_id: Task ID to poll
+        polling_interval: Seconds between poll attempts
+        polling_timeout: Max seconds before timeout
+        agent_branch: Agent tree branch for logging
+        history_length: Number of messages to retrieve per poll
+        max_polls: Max number of poll attempts (None = unlimited)

    Returns:
-        Final task object in terminal state.
+        Final task object in terminal state

    Raises:
-        A2APollingTimeoutError: If polling exceeds timeout or max_polls.
+        A2APollingTimeoutError: If polling exceeds timeout or max_polls
    """
    start_time = time.monotonic()
    poll_count = 0
@@ -88,19 +77,13 @@ async def _poll_task_until_complete(
        )

        elapsed = time.monotonic() - start_time
-        effective_context_id = task.context_id or context_id
        crewai_event_bus.emit(
            agent_branch,
            A2APollingStatusEvent(
                task_id=task_id,
-                context_id=effective_context_id,
                state=str(task.status.state.value) if task.status.state else "unknown",
                elapsed_seconds=elapsed,
                poll_count=poll_count,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            ),
        )

@@ -154,9 +137,6 @@ class PollingHandler:
        max_polls = kwargs.get("max_polls")
        context_id = kwargs.get("context_id")
        task_id = kwargs.get("task_id")
-        a2a_agent_name = kwargs.get("a2a_agent_name")
-        from_task = kwargs.get("from_task")
-        from_agent = kwargs.get("from_agent")

        try:
            result_or_task_id = await send_message_and_get_task_id(
@@ -166,11 +146,6 @@ class PollingHandler:
                turn_number=turn_number,
                is_multiturn=is_multiturn,
                agent_role=agent_role,
-                from_task=from_task,
-                from_agent=from_agent,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                context_id=context_id,
            )

            if not isinstance(result_or_task_id, str):
@@ -182,12 +157,8 @@ class PollingHandler:
                agent_branch,
                A2APollingStartedEvent(
                    task_id=task_id,
-                    context_id=context_id,
                    polling_interval=polling_interval,
                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )

@@ -199,11 +170,6 @@ class PollingHandler:
                agent_branch=agent_branch,
                history_length=history_length,
                max_polls=max_polls,
-                from_task=from_task,
-                from_agent=from_agent,
-                context_id=context_id,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
            )

            result = process_task_state(
@@ -213,10 +179,6 @@ class PollingHandler:
                turn_number=turn_number,
                is_multiturn=is_multiturn,
                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            )
            if result:
                return result
@@ -244,15 +206,9 @@ class PollingHandler:
                A2AResponseReceivedEvent(
                    response=error_msg,
                    turn_number=turn_number,
-                    context_id=context_id,
                    is_multiturn=is_multiturn,
                    status="failed",
-                    final=True,
                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )
            return TaskStateResult(
@@ -273,83 +229,14 @@ class PollingHandler:
            )
            new_messages.append(error_message)

-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint,
-                    error=str(e),
-                    error_type="http_error",
-                    status_code=e.status_code,
-                    a2a_agent_name=a2a_agent_name,
-                    operation="polling",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
            crewai_event_bus.emit(
                agent_branch,
                A2AResponseReceivedEvent(
                    response=error_msg,
                    turn_number=turn_number,
-                    context_id=context_id,
                    is_multiturn=is_multiturn,
                    status="failed",
-                    final=True,
                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            return TaskStateResult(
-                status=TaskState.failed,
-                error=error_msg,
-                history=new_messages,
-            )
-
-        except Exception as e:
-            error_msg = f"Unexpected error during polling: {e!s}"
-
-            error_message = Message(
-                role=Role.agent,
-                message_id=str(uuid.uuid4()),
-                parts=[Part(root=TextPart(text=error_msg))],
-                context_id=context_id,
-                task_id=task_id,
-            )
-            new_messages.append(error_message)
-
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=str(e),
-                    error_type="unexpected_error",
-                    a2a_agent_name=a2a_agent_name,
-                    operation="polling",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AResponseReceivedEvent(
-                    response=error_msg,
-                    turn_number=turn_number,
-                    context_id=context_id,
-                    is_multiturn=is_multiturn,
-                    status="failed",
-                    final=True,
-                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )
            return TaskStateResult(
--- a/lib/crewai/src/crewai/a2a/updates/push_notifications/handler.py
+++ b/lib/crewai/src/crewai/a2a/updates/push_notifications/handler.py
@@ -29,7 +29,6 @@ from crewai.a2a.updates.base import (
 )
 from crewai.events.event_bus import crewai_event_bus
 from crewai.events.types.a2a_events import (
-    A2AConnectionErrorEvent,
    A2APushNotificationRegisteredEvent,
    A2APushNotificationTimeoutEvent,
    A2AResponseReceivedEvent,
@@ -49,11 +48,6 @@ async def _wait_for_push_result(
    timeout: float,
    poll_interval: float,
    agent_branch: Any | None = None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    context_id: str | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
 ) -> A2ATask | None:
    """Wait for push notification result.

@@ -63,11 +57,6 @@ async def _wait_for_push_result(
        timeout: Max seconds to wait.
        poll_interval: Seconds between polling attempts.
        agent_branch: Agent tree branch for logging.
-        from_task: Optional CrewAI Task object for event metadata.
-        from_agent: Optional CrewAI Agent object for event metadata.
-        context_id: A2A context ID for correlation.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent.

    Returns:
        Final task object, or None if timeout.
@@ -83,12 +72,7 @@ async def _wait_for_push_result(
            agent_branch,
            A2APushNotificationTimeoutEvent(
                task_id=task_id,
-                context_id=context_id,
                timeout_seconds=timeout,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            ),
        )

@@ -131,56 +115,18 @@ class PushNotificationHandler:
        agent_role = kwargs.get("agent_role")
        context_id = kwargs.get("context_id")
        task_id = kwargs.get("task_id")
-        endpoint = kwargs.get("endpoint")
-        a2a_agent_name = kwargs.get("a2a_agent_name")
-        from_task = kwargs.get("from_task")
-        from_agent = kwargs.get("from_agent")

        if config is None:
-            error_msg = (
-                "PushNotificationConfig is required for push notification handler"
-            )
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=error_msg,
-                    error_type="configuration_error",
-                    a2a_agent_name=a2a_agent_name,
-                    operation="push_notification",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
            return TaskStateResult(
                status=TaskState.failed,
-                error=error_msg,
+                error="PushNotificationConfig is required for push notification handler",
                history=new_messages,
            )

        if result_store is None:
-            error_msg = (
-                "PushNotificationResultStore is required for push notification handler"
-            )
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=error_msg,
-                    error_type="configuration_error",
-                    a2a_agent_name=a2a_agent_name,
-                    operation="push_notification",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
            return TaskStateResult(
                status=TaskState.failed,
-                error=error_msg,
+                error="PushNotificationResultStore is required for push notification handler",
                history=new_messages,
            )

@@ -192,11 +138,6 @@ class PushNotificationHandler:
                turn_number=turn_number,
                is_multiturn=is_multiturn,
                agent_role=agent_role,
-                from_task=from_task,
-                from_agent=from_agent,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                context_id=context_id,
            )

            if not isinstance(result_or_task_id, str):
@@ -208,12 +149,7 @@ class PushNotificationHandler:
                agent_branch,
                A2APushNotificationRegisteredEvent(
                    task_id=task_id,
-                    context_id=context_id,
                    callback_url=str(config.url),
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )

@@ -229,11 +165,6 @@ class PushNotificationHandler:
                timeout=polling_timeout,
                poll_interval=polling_interval,
                agent_branch=agent_branch,
-                from_task=from_task,
-                from_agent=from_agent,
-                context_id=context_id,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
            )

            if final_task is None:
@@ -250,10 +181,6 @@ class PushNotificationHandler:
                turn_number=turn_number,
                is_multiturn=is_multiturn,
                agent_role=agent_role,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                from_task=from_task,
-                from_agent=from_agent,
            )
            if result:
                return result
@@ -276,83 +203,14 @@ class PushNotificationHandler:
            )
            new_messages.append(error_message)

-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=str(e),
-                    error_type="http_error",
-                    status_code=e.status_code,
-                    a2a_agent_name=a2a_agent_name,
-                    operation="push_notification",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
            crewai_event_bus.emit(
                agent_branch,
                A2AResponseReceivedEvent(
                    response=error_msg,
                    turn_number=turn_number,
-                    context_id=context_id,
                    is_multiturn=is_multiturn,
                    status="failed",
-                    final=True,
                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            return TaskStateResult(
-                status=TaskState.failed,
-                error=error_msg,
-                history=new_messages,
-            )
-
-        except Exception as e:
-            error_msg = f"Unexpected error during push notification: {e!s}"
-
-            error_message = Message(
-                role=Role.agent,
-                message_id=str(uuid.uuid4()),
-                parts=[Part(root=TextPart(text=error_msg))],
-                context_id=context_id,
-                task_id=task_id,
-            )
-            new_messages.append(error_message)
-
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=str(e),
-                    error_type="unexpected_error",
-                    a2a_agent_name=a2a_agent_name,
-                    operation="push_notification",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AResponseReceivedEvent(
-                    response=error_msg,
-                    turn_number=turn_number,
-                    context_id=context_id,
-                    is_multiturn=is_multiturn,
-                    status="failed",
-                    final=True,
-                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )
            return TaskStateResult(
--- a/lib/crewai/src/crewai/a2a/updates/streaming/handler.py
+++ b/lib/crewai/src/crewai/a2a/updates/streaming/handler.py
@@ -26,13 +26,7 @@ from crewai.a2a.task_helpers import (
 )
 from crewai.a2a.updates.base import StreamingHandlerKwargs
 from crewai.events.event_bus import crewai_event_bus
-from crewai.events.types.a2a_events import (
-    A2AArtifactReceivedEvent,
-    A2AConnectionErrorEvent,
-    A2AResponseReceivedEvent,
-    A2AStreamingChunkEvent,
-    A2AStreamingStartedEvent,
-)
+from crewai.events.types.a2a_events import A2AResponseReceivedEvent


 class StreamingHandler:
@@ -63,57 +57,19 @@ class StreamingHandler:
        turn_number = kwargs.get("turn_number", 0)
        is_multiturn = kwargs.get("is_multiturn", False)
        agent_role = kwargs.get("agent_role")
-        endpoint = kwargs.get("endpoint")
-        a2a_agent_name = kwargs.get("a2a_agent_name")
-        from_task = kwargs.get("from_task")
-        from_agent = kwargs.get("from_agent")
-        agent_branch = kwargs.get("agent_branch")

        result_parts: list[str] = []
        final_result: TaskStateResult | None = None
        event_stream = client.send_message(message)
-        chunk_index = 0
-
-        crewai_event_bus.emit(
-            agent_branch,
-            A2AStreamingStartedEvent(
-                task_id=task_id,
-                context_id=context_id,
-                endpoint=endpoint or "",
-                a2a_agent_name=a2a_agent_name,
-                turn_number=turn_number,
-                is_multiturn=is_multiturn,
-                agent_role=agent_role,
-                from_task=from_task,
-                from_agent=from_agent,
-            ),
-        )

        try:
            async for event in event_stream:
                if isinstance(event, Message):
                    new_messages.append(event)
-                    message_context_id = event.context_id or context_id
                    for part in event.parts:
                        if part.root.kind == "text":
                            text = part.root.text
                            result_parts.append(text)
-                            crewai_event_bus.emit(
-                                agent_branch,
-                                A2AStreamingChunkEvent(
-                                    task_id=event.task_id or task_id,
-                                    context_id=message_context_id,
-                                    chunk=text,
-                                    chunk_index=chunk_index,
-                                    endpoint=endpoint,
-                                    a2a_agent_name=a2a_agent_name,
-                                    turn_number=turn_number,
-                                    is_multiturn=is_multiturn,
-                                    from_task=from_task,
-                                    from_agent=from_agent,
-                                ),
-                            )
-                            chunk_index += 1

                elif isinstance(event, tuple):
                    a2a_task, update = event
@@ -125,51 +81,10 @@ class StreamingHandler:
                            for part in artifact.parts
                            if part.root.kind == "text"
                        )
-                        artifact_size = None
-                        if artifact.parts:
-                            artifact_size = sum(
-                                len(p.root.text.encode("utf-8"))
-                                if p.root.kind == "text"
-                                else len(getattr(p.root, "data", b""))
-                                for p in artifact.parts
-                            )
-                        effective_context_id = a2a_task.context_id or context_id
-                        crewai_event_bus.emit(
-                            agent_branch,
-                            A2AArtifactReceivedEvent(
-                                task_id=a2a_task.id,
-                                artifact_id=artifact.artifact_id,
-                                artifact_name=artifact.name,
-                                artifact_description=artifact.description,
-                                mime_type=artifact.parts[0].root.kind
-                                if artifact.parts
-                                else None,
-                                size_bytes=artifact_size,
-                                append=update.append or False,
-                                last_chunk=update.last_chunk or False,
-                                endpoint=endpoint,
-                                a2a_agent_name=a2a_agent_name,
-                                context_id=effective_context_id,
-                                turn_number=turn_number,
-                                is_multiturn=is_multiturn,
-                                from_task=from_task,
-                                from_agent=from_agent,
-                            ),
-                        )

                    is_final_update = False
                    if isinstance(update, TaskStatusUpdateEvent):
                        is_final_update = update.final
-                        if (
-                            update.status
-                            and update.status.message
-                            and update.status.message.parts
-                        ):
-                            result_parts.extend(
-                                part.root.text
-                                for part in update.status.message.parts
-                                if part.root.kind == "text" and part.root.text
-                            )

                    if (
                        not is_final_update
@@ -186,11 +101,6 @@ class StreamingHandler:
                        is_multiturn=is_multiturn,
                        agent_role=agent_role,
                        result_parts=result_parts,
-                        endpoint=endpoint,
-                        a2a_agent_name=a2a_agent_name,
-                        from_task=from_task,
-                        from_agent=from_agent,
-                        is_final=is_final_update,
                    )
                    if final_result:
                        break
@@ -208,82 +118,13 @@ class StreamingHandler:
            new_messages.append(error_message)

            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=str(e),
-                    error_type="http_error",
-                    status_code=e.status_code,
-                    a2a_agent_name=a2a_agent_name,
-                    operation="streaming",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            crewai_event_bus.emit(
-                agent_branch,
+                None,
                A2AResponseReceivedEvent(
                    response=error_msg,
                    turn_number=turn_number,
-                    context_id=context_id,
                    is_multiturn=is_multiturn,
                    status="failed",
-                    final=True,
                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            return TaskStateResult(
-                status=TaskState.failed,
-                error=error_msg,
-                history=new_messages,
-            )
-
-        except Exception as e:
-            error_msg = f"Unexpected error during streaming: {e!s}"
-
-            error_message = Message(
-                role=Role.agent,
-                message_id=str(uuid.uuid4()),
-                parts=[Part(root=TextPart(text=error_msg))],
-                context_id=context_id,
-                task_id=task_id,
-            )
-            new_messages.append(error_message)
-
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint or "",
-                    error=str(e),
-                    error_type="unexpected_error",
-                    a2a_agent_name=a2a_agent_name,
-                    operation="streaming",
-                    context_id=context_id,
-                    task_id=task_id,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                ),
-            )
-            crewai_event_bus.emit(
-                agent_branch,
-                A2AResponseReceivedEvent(
-                    response=error_msg,
-                    turn_number=turn_number,
-                    context_id=context_id,
-                    is_multiturn=is_multiturn,
-                    status="failed",
-                    final=True,
-                    agent_role=agent_role,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    from_task=from_task,
-                    from_agent=from_agent,
                ),
            )
            return TaskStateResult(
@@ -295,23 +136,7 @@ class StreamingHandler:
        finally:
            aclose = getattr(event_stream, "aclose", None)
            if aclose:
-                try:
-                    await aclose()
-                except Exception as close_error:
-                    crewai_event_bus.emit(
-                        agent_branch,
-                        A2AConnectionErrorEvent(
-                            endpoint=endpoint or "",
-                            error=str(close_error),
-                            error_type="stream_close_error",
-                            a2a_agent_name=a2a_agent_name,
-                            operation="stream_close",
-                            context_id=context_id,
-                            task_id=task_id,
-                            from_task=from_task,
-                            from_agent=from_agent,
-                        ),
-                    )
+                await aclose()

        if final_result:
            return final_result
@@ -320,5 +145,5 @@ class StreamingHandler:
            status=TaskState.completed,
            result=" ".join(result_parts) if result_parts else "",
            history=new_messages,
-            agent_card=agent_card.model_dump(exclude_none=True),
+            agent_card=agent_card,
        )
--- a/lib/crewai/src/crewai/a2a/utils/agent_card.py
+++ b/lib/crewai/src/crewai/a2a/utils/agent_card.py
@@ -23,12 +23,6 @@ from crewai.a2a.auth.utils import (
 )
 from crewai.a2a.config import A2AServerConfig
 from crewai.crew import Crew
-from crewai.events.event_bus import crewai_event_bus
-from crewai.events.types.a2a_events import (
-    A2AAgentCardFetchedEvent,
-    A2AAuthenticationFailedEvent,
-    A2AConnectionErrorEvent,
-)


 if TYPE_CHECKING:
@@ -189,8 +183,6 @@ async def _afetch_agent_card_impl(
    timeout: int,
 ) -> AgentCard:
    """Internal async implementation of AgentCard fetching."""
-    start_time = time.perf_counter()
-
    if "/.well-known/agent-card.json" in endpoint:
        base_url = endpoint.replace("/.well-known/agent-card.json", "")
        agent_card_path = "/.well-known/agent-card.json"
@@ -225,29 +217,9 @@ async def _afetch_agent_card_impl(
            )
            response.raise_for_status()

-            agent_card = AgentCard.model_validate(response.json())
-            fetch_time_ms = (time.perf_counter() - start_time) * 1000
-            agent_card_dict = agent_card.model_dump(exclude_none=True)
-
-            crewai_event_bus.emit(
-                None,
-                A2AAgentCardFetchedEvent(
-                    endpoint=endpoint,
-                    a2a_agent_name=agent_card.name,
-                    agent_card=agent_card_dict,
-                    protocol_version=agent_card.protocol_version,
-                    provider=agent_card_dict.get("provider"),
-                    cached=False,
-                    fetch_time_ms=fetch_time_ms,
-                ),
-            )
-
-            return agent_card
+            return AgentCard.model_validate(response.json())

        except httpx.HTTPStatusError as e:
-            elapsed_ms = (time.perf_counter() - start_time) * 1000
-            response_body = e.response.text[:1000] if e.response.text else None
-
            if e.response.status_code == 401:
                error_details = ["Authentication failed"]
                www_auth = e.response.headers.get("WWW-Authenticate")
@@ -256,93 +228,7 @@ async def _afetch_agent_card_impl(
                if not auth:
                    error_details.append("No auth scheme provided")
                msg = " | ".join(error_details)
-
-                auth_type = type(auth).__name__ if auth else None
-                crewai_event_bus.emit(
-                    None,
-                    A2AAuthenticationFailedEvent(
-                        endpoint=endpoint,
-                        auth_type=auth_type,
-                        error=msg,
-                        status_code=401,
-                        metadata={
-                            "elapsed_ms": elapsed_ms,
-                            "response_body": response_body,
-                            "www_authenticate": www_auth,
-                            "request_url": str(e.request.url),
-                        },
-                    ),
-                )
-
                raise A2AClientHTTPError(401, msg) from e
-
-            crewai_event_bus.emit(
-                None,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint,
-                    error=str(e),
-                    error_type="http_error",
-                    status_code=e.response.status_code,
-                    operation="fetch_agent_card",
-                    metadata={
-                        "elapsed_ms": elapsed_ms,
-                        "response_body": response_body,
-                        "request_url": str(e.request.url),
-                    },
-                ),
-            )
-            raise
-
-        except httpx.TimeoutException as e:
-            elapsed_ms = (time.perf_counter() - start_time) * 1000
-            crewai_event_bus.emit(
-                None,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint,
-                    error=str(e),
-                    error_type="timeout",
-                    operation="fetch_agent_card",
-                    metadata={
-                        "elapsed_ms": elapsed_ms,
-                        "timeout_config": timeout,
-                        "request_url": str(e.request.url) if e.request else None,
-                    },
-                ),
-            )
-            raise
-
-        except httpx.ConnectError as e:
-            elapsed_ms = (time.perf_counter() - start_time) * 1000
-            crewai_event_bus.emit(
-                None,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint,
-                    error=str(e),
-                    error_type="connection_error",
-                    operation="fetch_agent_card",
-                    metadata={
-                        "elapsed_ms": elapsed_ms,
-                        "request_url": str(e.request.url) if e.request else None,
-                    },
-                ),
-            )
-            raise
-
-        except httpx.RequestError as e:
-            elapsed_ms = (time.perf_counter() - start_time) * 1000
-            crewai_event_bus.emit(
-                None,
-                A2AConnectionErrorEvent(
-                    endpoint=endpoint,
-                    error=str(e),
-                    error_type="request_error",
-                    operation="fetch_agent_card",
-                    metadata={
-                        "elapsed_ms": elapsed_ms,
-                        "request_url": str(e.request.url) if e.request else None,
-                    },
-                ),
-            )
            raise


--- a/lib/crewai/src/crewai/a2a/utils/delegation.py
+++ b/lib/crewai/src/crewai/a2a/utils/delegation.py
@@ -88,9 +88,6 @@ def execute_a2a_delegation(
    response_model: type[BaseModel] | None = None,
    turn_number: int | None = None,
    updates: UpdateConfig | None = None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    skill_id: str | None = None,
 ) -> TaskStateResult:
    """Execute a task delegation to a remote A2A agent synchronously.

@@ -132,9 +129,6 @@ def execute_a2a_delegation(
        response_model: Optional Pydantic model for structured outputs.
        turn_number: Optional turn number for multi-turn conversations.
        updates: Update mechanism config from A2AConfig.updates.
-        from_task: Optional CrewAI Task object for event metadata.
-        from_agent: Optional CrewAI Agent object for event metadata.
-        skill_id: Optional skill ID to target a specific agent capability.

    Returns:
        TaskStateResult with status, result/error, history, and agent_card.
@@ -162,16 +156,10 @@ def execute_a2a_delegation(
                transport_protocol=transport_protocol,
                turn_number=turn_number,
                updates=updates,
-                from_task=from_task,
-                from_agent=from_agent,
-                skill_id=skill_id,
            )
        )
    finally:
-        try:
-            loop.run_until_complete(loop.shutdown_asyncgens())
-        finally:
-            loop.close()
+        loop.close()


 async def aexecute_a2a_delegation(
@@ -193,9 +181,6 @@ async def aexecute_a2a_delegation(
    response_model: type[BaseModel] | None = None,
    turn_number: int | None = None,
    updates: UpdateConfig | None = None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    skill_id: str | None = None,
 ) -> TaskStateResult:
    """Execute a task delegation to a remote A2A agent asynchronously.

@@ -237,9 +222,6 @@ async def aexecute_a2a_delegation(
        response_model: Optional Pydantic model for structured outputs.
        turn_number: Optional turn number for multi-turn conversations.
        updates: Update mechanism config from A2AConfig.updates.
-        from_task: Optional CrewAI Task object for event metadata.
-        from_agent: Optional CrewAI Agent object for event metadata.
-        skill_id: Optional skill ID to target a specific agent capability.

    Returns:
        TaskStateResult with status, result/error, history, and agent_card.
@@ -251,6 +233,17 @@ async def aexecute_a2a_delegation(
    if turn_number is None:
        turn_number = len([m for m in conversation_history if m.role == Role.user]) + 1

+    crewai_event_bus.emit(
+        agent_branch,
+        A2ADelegationStartedEvent(
+            endpoint=endpoint,
+            task_description=task_description,
+            agent_id=agent_id,
+            is_multiturn=is_multiturn,
+            turn_number=turn_number,
+        ),
+    )
+
    result = await _aexecute_a2a_delegation_impl(
        endpoint=endpoint,
        auth=auth,
@@ -271,28 +264,15 @@ async def aexecute_a2a_delegation(
        response_model=response_model,
        updates=updates,
        transport_protocol=transport_protocol,
-        from_task=from_task,
-        from_agent=from_agent,
-        skill_id=skill_id,
    )

-    agent_card_data: dict[str, Any] = result.get("agent_card") or {}
    crewai_event_bus.emit(
        agent_branch,
        A2ADelegationCompletedEvent(
            status=result["status"],
            result=result.get("result"),
            error=result.get("error"),
-            context_id=context_id,
            is_multiturn=is_multiturn,
-            endpoint=endpoint,
-            a2a_agent_name=result.get("a2a_agent_name"),
-            agent_card=agent_card_data,
-            provider=agent_card_data.get("provider"),
-            metadata=metadata,
-            extensions=list(extensions.keys()) if extensions else None,
-            from_task=from_task,
-            from_agent=from_agent,
        ),
    )

@@ -319,9 +299,6 @@ async def _aexecute_a2a_delegation_impl(
    agent_role: str | None,
    response_model: type[BaseModel] | None,
    updates: UpdateConfig | None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    skill_id: str | None = None,
 ) -> TaskStateResult:
    """Internal async implementation of A2A delegation."""
    if auth:
@@ -354,28 +331,6 @@ async def _aexecute_a2a_delegation_impl(
    if agent_card.name:
        a2a_agent_name = agent_card.name

-    agent_card_dict = agent_card.model_dump(exclude_none=True)
-    crewai_event_bus.emit(
-        agent_branch,
-        A2ADelegationStartedEvent(
-            endpoint=endpoint,
-            task_description=task_description,
-            agent_id=agent_id or endpoint,
-            context_id=context_id,
-            is_multiturn=is_multiturn,
-            turn_number=turn_number,
-            a2a_agent_name=a2a_agent_name,
-            agent_card=agent_card_dict,
-            protocol_version=agent_card.protocol_version,
-            provider=agent_card_dict.get("provider"),
-            skill_id=skill_id,
-            metadata=metadata,
-            extensions=list(extensions.keys()) if extensions else None,
-            from_task=from_task,
-            from_agent=from_agent,
-        ),
-    )
-
    if turn_number == 1:
        agent_id_for_event = agent_id or endpoint
        crewai_event_bus.emit(
@@ -383,17 +338,7 @@ async def _aexecute_a2a_delegation_impl(
            A2AConversationStartedEvent(
                agent_id=agent_id_for_event,
                endpoint=endpoint,
-                context_id=context_id,
                a2a_agent_name=a2a_agent_name,
-                agent_card=agent_card_dict,
-                protocol_version=agent_card.protocol_version,
-                provider=agent_card_dict.get("provider"),
-                skill_id=skill_id,
-                reference_task_ids=reference_task_ids,
-                metadata=metadata,
-                extensions=list(extensions.keys()) if extensions else None,
-                from_task=from_task,
-                from_agent=from_agent,
            ),
        )

@@ -419,10 +364,6 @@ async def _aexecute_a2a_delegation_impl(
            }
        )

-    message_metadata = metadata.copy() if metadata else {}
-    if skill_id:
-        message_metadata["skill_id"] = skill_id
-
    message = Message(
        role=Role.user,
        message_id=str(uuid.uuid4()),
@@ -430,7 +371,7 @@ async def _aexecute_a2a_delegation_impl(
        context_id=context_id,
        task_id=task_id,
        reference_task_ids=reference_task_ids,
-        metadata=message_metadata if message_metadata else None,
+        metadata=metadata,
        extensions=extensions,
    )

@@ -440,17 +381,8 @@ async def _aexecute_a2a_delegation_impl(
        A2AMessageSentEvent(
            message=message_text,
            turn_number=turn_number,
-            context_id=context_id,
-            message_id=message.message_id,
            is_multiturn=is_multiturn,
            agent_role=agent_role,
-            endpoint=endpoint,
-            a2a_agent_name=a2a_agent_name,
-            skill_id=skill_id,
-            metadata=message_metadata if message_metadata else None,
-            extensions=list(extensions.keys()) if extensions else None,
-            from_task=from_task,
-            from_agent=from_agent,
        ),
    )

@@ -465,9 +397,6 @@ async def _aexecute_a2a_delegation_impl(
        "task_id": task_id,
        "endpoint": endpoint,
        "agent_branch": agent_branch,
-        "a2a_agent_name": a2a_agent_name,
-        "from_task": from_task,
-        "from_agent": from_agent,
    }

    if isinstance(updates, PollingConfig):
@@ -505,16 +434,13 @@ async def _aexecute_a2a_delegation_impl(
        use_polling=use_polling,
        push_notification_config=push_config_for_client,
    ) as client:
-        result = await handler.execute(
+        return await handler.execute(
            client=client,
            message=message,
            new_messages=new_messages,
            agent_card=agent_card,
            **handler_kwargs,
        )
-        result["a2a_agent_name"] = a2a_agent_name
-        result["agent_card"] = agent_card.model_dump(exclude_none=True)
-        return result


@asynccontextmanager
--- a/lib/crewai/src/crewai/a2a/utils/task.py
+++ b/lib/crewai/src/crewai/a2a/utils/task.py
@@ -3,14 +3,11 @@
 from __future__ import annotations

 import asyncio
-import base64
 from collections.abc import Callable, Coroutine
-from datetime import datetime
 from functools import wraps
 import logging
 import os
 from typing import TYPE_CHECKING, Any, ParamSpec, TypeVar, cast
-from urllib.parse import urlparse

 from a2a.server.agent_execution import RequestContext
 from a2a.server.events import EventQueue
@@ -48,14 +45,7 @@ T = TypeVar("T")


 def _parse_redis_url(url: str) -> dict[str, Any]:
-    """Parse a Redis URL into aiocache configuration.
-
-    Args:
-        url: Redis connection URL (e.g., redis://localhost:6379/0).
-
-    Returns:
-        Configuration dict for aiocache.RedisCache.
-    """
+    from urllib.parse import urlparse

    parsed = urlparse(url)
    config: dict[str, Any] = {
@@ -137,7 +127,7 @@ def cancellable(
                async for message in pubsub.listen():
                    if message["type"] == "message":
                        return True
-            except (OSError, ConnectionError) as e:
+            except Exception as e:
                logger.warning("Cancel watcher error for task_id=%s: %s", task_id, e)
                return await poll_for_cancel()
            return False
@@ -193,12 +183,7 @@ async def execute(
        msg = "task_id and context_id are required"
        crewai_event_bus.emit(
            agent,
-            A2AServerTaskFailedEvent(
-                task_id="",
-                context_id="",
-                error=msg,
-                from_agent=agent,
-            ),
+            A2AServerTaskFailedEvent(a2a_task_id="", a2a_context_id="", error=msg),
        )
        raise ServerError(InvalidParamsError(message=msg)) from None

@@ -210,12 +195,7 @@ async def execute(

    crewai_event_bus.emit(
        agent,
-        A2AServerTaskStartedEvent(
-            task_id=task_id,
-            context_id=context_id,
-            from_task=task,
-            from_agent=agent,
-        ),
+        A2AServerTaskStartedEvent(a2a_task_id=task_id, a2a_context_id=context_id),
    )

    try:
@@ -235,33 +215,20 @@ async def execute(
        crewai_event_bus.emit(
            agent,
            A2AServerTaskCompletedEvent(
-                task_id=task_id,
-                context_id=context_id,
-                result=str(result),
-                from_task=task,
-                from_agent=agent,
+                a2a_task_id=task_id, a2a_context_id=context_id, result=str(result)
            ),
        )
    except asyncio.CancelledError:
        crewai_event_bus.emit(
            agent,
-            A2AServerTaskCanceledEvent(
-                task_id=task_id,
-                context_id=context_id,
-                from_task=task,
-                from_agent=agent,
-            ),
+            A2AServerTaskCanceledEvent(a2a_task_id=task_id, a2a_context_id=context_id),
        )
        raise
    except Exception as e:
        crewai_event_bus.emit(
            agent,
            A2AServerTaskFailedEvent(
-                task_id=task_id,
-                context_id=context_id,
-                error=str(e),
-                from_task=task,
-                from_agent=agent,
+                a2a_task_id=task_id, a2a_context_id=context_id, error=str(e)
            ),
        )
        raise ServerError(
@@ -315,85 +282,3 @@ async def cancel(
        context.current_task.status = TaskStatus(state=TaskState.canceled)
        return context.current_task
    return None
-
-
-def list_tasks(
-    tasks: list[A2ATask],
-    context_id: str | None = None,
-    status: TaskState | None = None,
-    status_timestamp_after: datetime | None = None,
-    page_size: int = 50,
-    page_token: str | None = None,
-    history_length: int | None = None,
-    include_artifacts: bool = False,
-) -> tuple[list[A2ATask], str | None, int]:
-    """Filter and paginate A2A tasks.
-
-    Provides filtering by context, status, and timestamp, along with
-    cursor-based pagination. This is a pure utility function that operates
-    on an in-memory list of tasks - storage retrieval is handled separately.
-
-    Args:
-        tasks: All tasks to filter.
-        context_id: Filter by context ID to get tasks in a conversation.
-        status: Filter by task state (e.g., completed, working).
-        status_timestamp_after: Filter to tasks updated after this time.
-        page_size: Maximum tasks per page (default 50).
-        page_token: Base64-encoded cursor from previous response.
-        history_length: Limit history messages per task (None = full history).
-        include_artifacts: Whether to include task artifacts (default False).
-
-    Returns:
-        Tuple of (filtered_tasks, next_page_token, total_count).
-        - filtered_tasks: Tasks matching filters, paginated and trimmed.
-        - next_page_token: Token for next page, or None if no more pages.
-        - total_count: Total number of tasks matching filters (before pagination).
-    """
-    filtered: list[A2ATask] = []
-    for task in tasks:
-        if context_id and task.context_id != context_id:
-            continue
-        if status and task.status.state != status:
-            continue
-        if status_timestamp_after and task.status.timestamp:
-            ts = datetime.fromisoformat(task.status.timestamp.replace("Z", "+00:00"))
-            if ts <= status_timestamp_after:
-                continue
-        filtered.append(task)
-
-    def get_timestamp(t: A2ATask) -> datetime:
-        """Extract timestamp from task status for sorting."""
-        if t.status.timestamp is None:
-            return datetime.min
-        return datetime.fromisoformat(t.status.timestamp.replace("Z", "+00:00"))
-
-    filtered.sort(key=get_timestamp, reverse=True)
-    total = len(filtered)
-
-    start = 0
-    if page_token:
-        try:
-            cursor_id = base64.b64decode(page_token).decode()
-            for idx, task in enumerate(filtered):
-                if task.id == cursor_id:
-                    start = idx + 1
-                    break
-        except (ValueError, UnicodeDecodeError):
-            pass
-
-    page = filtered[start : start + page_size]
-
-    result: list[A2ATask] = []
-    for task in page:
-        task = task.model_copy(deep=True)
-        if history_length is not None and task.history:
-            task.history = task.history[-history_length:]
-        if not include_artifacts:
-            task.artifacts = None
-        result.append(task)
-
-    next_token: str | None = None
-    if result and len(result) == page_size:
-        next_token = base64.b64encode(result[-1].id.encode()).decode()
-
-    return result, next_token, total
--- a/lib/crewai/src/crewai/a2a/wrapper.py
+++ b/lib/crewai/src/crewai/a2a/wrapper.py
@@ -6,10 +6,9 @@ Wraps agent classes with A2A delegation capabilities.
 from __future__ import annotations

 import asyncio
-from collections.abc import Callable, Coroutine, Mapping
+from collections.abc import Callable, Coroutine
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from functools import wraps
-import json
 from types import MethodType
 from typing import TYPE_CHECKING, Any

@@ -190,7 +189,7 @@ def _execute_task_with_a2a(
    a2a_agents: list[A2AConfig | A2AClientConfig],
    original_fn: Callable[..., str],
    task: Task,
-    agent_response_model: type[BaseModel] | None,
+    agent_response_model: type[BaseModel],
    context: str | None,
    tools: list[BaseTool] | None,
    extension_registry: ExtensionRegistry,
@@ -278,7 +277,7 @@ def _execute_task_with_a2a(
 def _augment_prompt_with_a2a(
    a2a_agents: list[A2AConfig | A2AClientConfig],
    task_description: str,
-    agent_cards: Mapping[str, AgentCard | dict[str, Any]],
+    agent_cards: dict[str, AgentCard],
    conversation_history: list[Message] | None = None,
    turn_num: int = 0,
    max_turns: int | None = None,
@@ -310,15 +309,7 @@ def _augment_prompt_with_a2a(
    for config in a2a_agents:
        if config.endpoint in agent_cards:
            card = agent_cards[config.endpoint]
-            if isinstance(card, dict):
-                filtered = {
-                    k: v
-                    for k, v in card.items()
-                    if k in {"description", "url", "skills"} and v is not None
-                }
-                agents_text += f"\n{json.dumps(filtered, indent=2)}\n"
-            else:
-                agents_text += f"\n{card.model_dump_json(indent=2, exclude_none=True, include={'description', 'url', 'skills'})}\n"
+            agents_text += f"\n{card.model_dump_json(indent=2, exclude_none=True, include={'description', 'url', 'skills'})}\n"

    failed_agents = failed_agents or {}
    if failed_agents:
@@ -386,7 +377,7 @@ IMPORTANT: You have the ability to delegate this task to remote A2A agents.


 def _parse_agent_response(
-    raw_result: str | dict[str, Any], agent_response_model: type[BaseModel] | None
+    raw_result: str | dict[str, Any], agent_response_model: type[BaseModel]
 ) -> BaseModel | str | dict[str, Any]:
    """Parse LLM output as AgentResponse or return raw agent response."""
    if agent_response_model:
@@ -403,11 +394,6 @@ def _parse_agent_response(
 def _handle_max_turns_exceeded(
    conversation_history: list[Message],
    max_turns: int,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    agent_card: dict[str, Any] | None = None,
 ) -> str:
    """Handle the case when max turns is exceeded.

@@ -435,11 +421,6 @@ def _handle_max_turns_exceeded(
                        final_result=final_message,
                        error=None,
                        total_turns=max_turns,
-                        from_task=from_task,
-                        from_agent=from_agent,
-                        endpoint=endpoint,
-                        a2a_agent_name=a2a_agent_name,
-                        agent_card=agent_card,
                    ),
                )
                return final_message
@@ -451,11 +432,6 @@ def _handle_max_turns_exceeded(
            final_result=None,
            error=f"Conversation exceeded maximum turns ({max_turns})",
            total_turns=max_turns,
-            from_task=from_task,
-            from_agent=from_agent,
-            endpoint=endpoint,
-            a2a_agent_name=a2a_agent_name,
-            agent_card=agent_card,
        ),
    )
    raise Exception(f"A2A conversation exceeded maximum turns ({max_turns})")
@@ -466,12 +442,7 @@ def _process_response_result(
    disable_structured_output: bool,
    turn_num: int,
    agent_role: str,
-    agent_response_model: type[BaseModel] | None,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    agent_card: dict[str, Any] | None = None,
+    agent_response_model: type[BaseModel],
 ) -> tuple[str | None, str | None]:
    """Process LLM response and determine next action.

@@ -490,10 +461,6 @@ def _process_response_result(
                turn_number=final_turn_number,
                is_multiturn=True,
                agent_role=agent_role,
-                from_task=from_task,
-                from_agent=from_agent,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
            ),
        )
        crewai_event_bus.emit(
@@ -503,11 +470,6 @@ def _process_response_result(
                final_result=result_text,
                error=None,
                total_turns=final_turn_number,
-                from_task=from_task,
-                from_agent=from_agent,
-                endpoint=endpoint,
-                a2a_agent_name=a2a_agent_name,
-                agent_card=agent_card,
            ),
        )
        return result_text, None
@@ -528,10 +490,6 @@ def _process_response_result(
                    turn_number=final_turn_number,
                    is_multiturn=True,
                    agent_role=agent_role,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
                ),
            )
            crewai_event_bus.emit(
@@ -541,11 +499,6 @@ def _process_response_result(
                    final_result=str(llm_response.message),
                    error=None,
                    total_turns=final_turn_number,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    agent_card=agent_card,
                ),
            )
            return str(llm_response.message), None
@@ -557,15 +510,13 @@ def _process_response_result(
 def _prepare_agent_cards_dict(
    a2a_result: TaskStateResult,
    agent_id: str,
-    agent_cards: Mapping[str, AgentCard | dict[str, Any]] | None,
-) -> dict[str, AgentCard | dict[str, Any]]:
+    agent_cards: dict[str, AgentCard] | None,
+) -> dict[str, AgentCard]:
    """Prepare agent cards dictionary from result and existing cards.

    Shared logic for both sync and async response handlers.
    """
-    agent_cards_dict: dict[str, AgentCard | dict[str, Any]] = (
-        dict(agent_cards) if agent_cards else {}
-    )
+    agent_cards_dict = agent_cards or {}
    if "agent_card" in a2a_result and agent_id not in agent_cards_dict:
        agent_cards_dict[agent_id] = a2a_result["agent_card"]
    return agent_cards_dict
@@ -578,7 +529,7 @@ def _prepare_delegation_context(
    original_task_description: str | None,
 ) -> tuple[
    list[A2AConfig | A2AClientConfig],
-    type[BaseModel] | None,
+    type[BaseModel],
    str,
    str,
    A2AConfig | A2AClientConfig,
@@ -647,11 +598,6 @@ def _handle_task_completion(
    reference_task_ids: list[str],
    agent_config: A2AConfig | A2AClientConfig,
    turn_num: int,
-    from_task: Any | None = None,
-    from_agent: Any | None = None,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    agent_card: dict[str, Any] | None = None,
 ) -> tuple[str | None, str | None, list[str]]:
    """Handle task completion state including reference task updates.

@@ -678,11 +624,6 @@ def _handle_task_completion(
                    final_result=result_text,
                    error=None,
                    total_turns=final_turn_number,
-                    from_task=from_task,
-                    from_agent=from_agent,
-                    endpoint=endpoint,
-                    a2a_agent_name=a2a_agent_name,
-                    agent_card=agent_card,
                ),
            )
            return str(result_text), task_id_config, reference_task_ids
@@ -704,11 +645,8 @@ def _handle_agent_response_and_continue(
    original_fn: Callable[..., str],
    context: str | None,
    tools: list[BaseTool] | None,
-    agent_response_model: type[BaseModel] | None,
+    agent_response_model: type[BaseModel],
    remote_task_completed: bool = False,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    agent_card: dict[str, Any] | None = None,
 ) -> tuple[str | None, str | None]:
    """Handle A2A result and get CrewAI agent's response.

@@ -760,11 +698,6 @@ def _handle_agent_response_and_continue(
        turn_num=turn_num,
        agent_role=self.role,
        agent_response_model=agent_response_model,
-        from_task=task,
-        from_agent=self,
-        endpoint=endpoint,
-        a2a_agent_name=a2a_agent_name,
-        agent_card=agent_card,
    )


@@ -817,12 +750,6 @@ def _delegate_to_a2a(

    conversation_history: list[Message] = []

-    current_agent_card = agent_cards.get(agent_id) if agent_cards else None
-    current_agent_card_dict = (
-        current_agent_card.model_dump() if current_agent_card else None
-    )
-    current_a2a_agent_name = current_agent_card.name if current_agent_card else None
-
    try:
        for turn_num in range(max_turns):
            console_formatter = getattr(crewai_event_bus, "_console", None)
@@ -850,8 +777,6 @@ def _delegate_to_a2a(
                turn_number=turn_num + 1,
                updates=agent_config.updates,
                transport_protocol=agent_config.transport_protocol,
-                from_task=task,
-                from_agent=self,
            )

            conversation_history = a2a_result.get("history", [])
@@ -872,11 +797,6 @@ def _delegate_to_a2a(
                        reference_task_ids,
                        agent_config,
                        turn_num,
-                        from_task=task,
-                        from_agent=self,
-                        endpoint=agent_config.endpoint,
-                        a2a_agent_name=current_a2a_agent_name,
-                        agent_card=current_agent_card_dict,
                    )
                )
                if trusted_result is not None:
@@ -898,9 +818,6 @@ def _delegate_to_a2a(
                    tools=tools,
                    agent_response_model=agent_response_model,
                    remote_task_completed=(a2a_result["status"] == TaskState.completed),
-                    endpoint=agent_config.endpoint,
-                    a2a_agent_name=current_a2a_agent_name,
-                    agent_card=current_agent_card_dict,
                )

                if final_result is not None:
@@ -929,9 +846,6 @@ def _delegate_to_a2a(
                tools=tools,
                agent_response_model=agent_response_model,
                remote_task_completed=False,
-                endpoint=agent_config.endpoint,
-                a2a_agent_name=current_a2a_agent_name,
-                agent_card=current_agent_card_dict,
            )

            if final_result is not None:
@@ -948,24 +862,11 @@ def _delegate_to_a2a(
                    final_result=None,
                    error=error_msg,
                    total_turns=turn_num + 1,
-                    from_task=task,
-                    from_agent=self,
-                    endpoint=agent_config.endpoint,
-                    a2a_agent_name=current_a2a_agent_name,
-                    agent_card=current_agent_card_dict,
                ),
            )
            return f"A2A delegation failed: {error_msg}"

-        return _handle_max_turns_exceeded(
-            conversation_history,
-            max_turns,
-            from_task=task,
-            from_agent=self,
-            endpoint=agent_config.endpoint,
-            a2a_agent_name=current_a2a_agent_name,
-            agent_card=current_agent_card_dict,
-        )
+        return _handle_max_turns_exceeded(conversation_history, max_turns)

    finally:
        task.description = original_task_description
@@ -1015,7 +916,7 @@ async def _aexecute_task_with_a2a(
    a2a_agents: list[A2AConfig | A2AClientConfig],
    original_fn: Callable[..., Coroutine[Any, Any, str]],
    task: Task,
-    agent_response_model: type[BaseModel] | None,
+    agent_response_model: type[BaseModel],
    context: str | None,
    tools: list[BaseTool] | None,
    extension_registry: ExtensionRegistry,
@@ -1100,11 +1001,8 @@ async def _ahandle_agent_response_and_continue(
    original_fn: Callable[..., Coroutine[Any, Any, str]],
    context: str | None,
    tools: list[BaseTool] | None,
-    agent_response_model: type[BaseModel] | None,
+    agent_response_model: type[BaseModel],
    remote_task_completed: bool = False,
-    endpoint: str | None = None,
-    a2a_agent_name: str | None = None,
-    agent_card: dict[str, Any] | None = None,
 ) -> tuple[str | None, str | None]:
    """Async version of _handle_agent_response_and_continue."""
    agent_cards_dict = _prepare_agent_cards_dict(a2a_result, agent_id, agent_cards)
@@ -1134,11 +1032,6 @@ async def _ahandle_agent_response_and_continue(
        turn_num=turn_num,
        agent_role=self.role,
        agent_response_model=agent_response_model,
-        from_task=task,
-        from_agent=self,
-        endpoint=endpoint,
-        a2a_agent_name=a2a_agent_name,
-        agent_card=agent_card,
    )


@@ -1173,12 +1066,6 @@ async def _adelegate_to_a2a(

    conversation_history: list[Message] = []

-    current_agent_card = agent_cards.get(agent_id) if agent_cards else None
-    current_agent_card_dict = (
-        current_agent_card.model_dump() if current_agent_card else None
-    )
-    current_a2a_agent_name = current_agent_card.name if current_agent_card else None
-
    try:
        for turn_num in range(max_turns):
            console_formatter = getattr(crewai_event_bus, "_console", None)
@@ -1206,8 +1093,6 @@ async def _adelegate_to_a2a(
                turn_number=turn_num + 1,
                transport_protocol=agent_config.transport_protocol,
                updates=agent_config.updates,
-                from_task=task,
-                from_agent=self,
            )

            conversation_history = a2a_result.get("history", [])
@@ -1228,11 +1113,6 @@ async def _adelegate_to_a2a(
                        reference_task_ids,
                        agent_config,
                        turn_num,
-                        from_task=task,
-                        from_agent=self,
-                        endpoint=agent_config.endpoint,
-                        a2a_agent_name=current_a2a_agent_name,
-                        agent_card=current_agent_card_dict,
                    )
                )
                if trusted_result is not None:
@@ -1254,9 +1134,6 @@ async def _adelegate_to_a2a(
                    tools=tools,
                    agent_response_model=agent_response_model,
                    remote_task_completed=(a2a_result["status"] == TaskState.completed),
-                    endpoint=agent_config.endpoint,
-                    a2a_agent_name=current_a2a_agent_name,
-                    agent_card=current_agent_card_dict,
                )

                if final_result is not None:
@@ -1284,9 +1161,6 @@ async def _adelegate_to_a2a(
                context=context,
                tools=tools,
                agent_response_model=agent_response_model,
-                endpoint=agent_config.endpoint,
-                a2a_agent_name=current_a2a_agent_name,
-                agent_card=current_agent_card_dict,
            )

            if final_result is not None:
@@ -1303,24 +1177,11 @@ async def _adelegate_to_a2a(
                    final_result=None,
                    error=error_msg,
                    total_turns=turn_num + 1,
-                    from_task=task,
-                    from_agent=self,
-                    endpoint=agent_config.endpoint,
-                    a2a_agent_name=current_a2a_agent_name,
-                    agent_card=current_agent_card_dict,
                ),
            )
            return f"A2A delegation failed: {error_msg}"

-        return _handle_max_turns_exceeded(
-            conversation_history,
-            max_turns,
-            from_task=task,
-            from_agent=self,
-            endpoint=agent_config.endpoint,
-            a2a_agent_name=current_a2a_agent_name,
-            agent_card=current_agent_card_dict,
-        )
+        return _handle_max_turns_exceeded(conversation_history, max_turns)

    finally:
        task.description = original_task_description
--- a/lib/crewai/src/crewai/events/event_types.py
+++ b/lib/crewai/src/crewai/events/event_types.py
@@ -1,28 +1,19 @@
 from crewai.events.types.a2a_events import (
-    A2AAgentCardFetchedEvent,
-    A2AArtifactReceivedEvent,
-    A2AAuthenticationFailedEvent,
-    A2AConnectionErrorEvent,
    A2AConversationCompletedEvent,
    A2AConversationStartedEvent,
    A2ADelegationCompletedEvent,
    A2ADelegationStartedEvent,
    A2AMessageSentEvent,
-    A2AParallelDelegationCompletedEvent,
-    A2AParallelDelegationStartedEvent,
    A2APollingStartedEvent,
    A2APollingStatusEvent,
    A2APushNotificationReceivedEvent,
    A2APushNotificationRegisteredEvent,
-    A2APushNotificationSentEvent,
    A2APushNotificationTimeoutEvent,
    A2AResponseReceivedEvent,
    A2AServerTaskCanceledEvent,
    A2AServerTaskCompletedEvent,
    A2AServerTaskFailedEvent,
    A2AServerTaskStartedEvent,
-    A2AStreamingChunkEvent,
-    A2AStreamingStartedEvent,
 )
 from crewai.events.types.agent_events import (
    AgentExecutionCompletedEvent,
@@ -102,11 +93,7 @@ from crewai.events.types.tool_usage_events import (


 EventTypes = (
-    A2AAgentCardFetchedEvent
-    | A2AArtifactReceivedEvent
-    | A2AAuthenticationFailedEvent
-    | A2AConnectionErrorEvent
-    | A2AConversationCompletedEvent
+    A2AConversationCompletedEvent
    | A2AConversationStartedEvent
    | A2ADelegationCompletedEvent
    | A2ADelegationStartedEvent
@@ -115,17 +102,12 @@ EventTypes = (
    | A2APollingStatusEvent
    | A2APushNotificationReceivedEvent
    | A2APushNotificationRegisteredEvent
-    | A2APushNotificationSentEvent
    | A2APushNotificationTimeoutEvent
    | A2AResponseReceivedEvent
    | A2AServerTaskCanceledEvent
    | A2AServerTaskCompletedEvent
    | A2AServerTaskFailedEvent
    | A2AServerTaskStartedEvent
-    | A2AStreamingChunkEvent
-    | A2AStreamingStartedEvent
-    | A2AParallelDelegationStartedEvent
-    | A2AParallelDelegationCompletedEvent
    | CrewKickoffStartedEvent
    | CrewKickoffCompletedEvent
    | CrewKickoffFailedEvent
--- a/lib/crewai/src/crewai/events/listeners/tracing/trace_listener.py
+++ b/lib/crewai/src/crewai/events/listeners/tracing/trace_listener.py
@@ -1,7 +1,7 @@
 """Trace collection listener for orchestrating trace collection."""

 import os
-from typing import Any, ClassVar
+from typing import Any, ClassVar, cast
 import uuid

 from typing_extensions import Self
@@ -18,32 +18,6 @@ from crewai.events.listeners.tracing.types import TraceEvent
 from crewai.events.listeners.tracing.utils import (
    safe_serialize_to_dict,
 )
-from crewai.events.types.a2a_events import (
-    A2AAgentCardFetchedEvent,
-    A2AArtifactReceivedEvent,
-    A2AAuthenticationFailedEvent,
-    A2AConnectionErrorEvent,
-    A2AConversationCompletedEvent,
-    A2AConversationStartedEvent,
-    A2ADelegationCompletedEvent,
-    A2ADelegationStartedEvent,
-    A2AMessageSentEvent,
-    A2AParallelDelegationCompletedEvent,
-    A2AParallelDelegationStartedEvent,
-    A2APollingStartedEvent,
-    A2APollingStatusEvent,
-    A2APushNotificationReceivedEvent,
-    A2APushNotificationRegisteredEvent,
-    A2APushNotificationSentEvent,
-    A2APushNotificationTimeoutEvent,
-    A2AResponseReceivedEvent,
-    A2AServerTaskCanceledEvent,
-    A2AServerTaskCompletedEvent,
-    A2AServerTaskFailedEvent,
-    A2AServerTaskStartedEvent,
-    A2AStreamingChunkEvent,
-    A2AStreamingStartedEvent,
-)
 from crewai.events.types.agent_events import (
    AgentExecutionCompletedEvent,
    AgentExecutionErrorEvent,
@@ -131,7 +105,7 @@ class TraceCollectionListener(BaseEventListener):
        """Create or return singleton instance."""
        if cls._instance is None:
            cls._instance = super().__new__(cls)
-        return cls._instance
+        return cast(Self, cls._instance)

    def __init__(
        self,
@@ -186,7 +160,6 @@ class TraceCollectionListener(BaseEventListener):
        self._register_flow_event_handlers(crewai_event_bus)
        self._register_context_event_handlers(crewai_event_bus)
        self._register_action_event_handlers(crewai_event_bus)
-        self._register_a2a_event_handlers(crewai_event_bus)
        self._register_system_event_handlers(crewai_event_bus)

        self._listeners_setup = True
@@ -466,147 +439,6 @@ class TraceCollectionListener(BaseEventListener):
        ) -> None:
            self._handle_action_event("knowledge_query_failed", source, event)

-    def _register_a2a_event_handlers(self, event_bus: CrewAIEventsBus) -> None:
-        """Register handlers for A2A (Agent-to-Agent) events."""
-
-        @event_bus.on(A2ADelegationStartedEvent)
-        def on_a2a_delegation_started(
-            source: Any, event: A2ADelegationStartedEvent
-        ) -> None:
-            self._handle_action_event("a2a_delegation_started", source, event)
-
-        @event_bus.on(A2ADelegationCompletedEvent)
-        def on_a2a_delegation_completed(
-            source: Any, event: A2ADelegationCompletedEvent
-        ) -> None:
-            self._handle_action_event("a2a_delegation_completed", source, event)
-
-        @event_bus.on(A2AConversationStartedEvent)
-        def on_a2a_conversation_started(
-            source: Any, event: A2AConversationStartedEvent
-        ) -> None:
-            self._handle_action_event("a2a_conversation_started", source, event)
-
-        @event_bus.on(A2AMessageSentEvent)
-        def on_a2a_message_sent(source: Any, event: A2AMessageSentEvent) -> None:
-            self._handle_action_event("a2a_message_sent", source, event)
-
-        @event_bus.on(A2AResponseReceivedEvent)
-        def on_a2a_response_received(
-            source: Any, event: A2AResponseReceivedEvent
-        ) -> None:
-            self._handle_action_event("a2a_response_received", source, event)
-
-        @event_bus.on(A2AConversationCompletedEvent)
-        def on_a2a_conversation_completed(
-            source: Any, event: A2AConversationCompletedEvent
-        ) -> None:
-            self._handle_action_event("a2a_conversation_completed", source, event)
-
-        @event_bus.on(A2APollingStartedEvent)
-        def on_a2a_polling_started(source: Any, event: A2APollingStartedEvent) -> None:
-            self._handle_action_event("a2a_polling_started", source, event)
-
-        @event_bus.on(A2APollingStatusEvent)
-        def on_a2a_polling_status(source: Any, event: A2APollingStatusEvent) -> None:
-            self._handle_action_event("a2a_polling_status", source, event)
-
-        @event_bus.on(A2APushNotificationRegisteredEvent)
-        def on_a2a_push_notification_registered(
-            source: Any, event: A2APushNotificationRegisteredEvent
-        ) -> None:
-            self._handle_action_event("a2a_push_notification_registered", source, event)
-
-        @event_bus.on(A2APushNotificationReceivedEvent)
-        def on_a2a_push_notification_received(
-            source: Any, event: A2APushNotificationReceivedEvent
-        ) -> None:
-            self._handle_action_event("a2a_push_notification_received", source, event)
-
-        @event_bus.on(A2APushNotificationSentEvent)
-        def on_a2a_push_notification_sent(
-            source: Any, event: A2APushNotificationSentEvent
-        ) -> None:
-            self._handle_action_event("a2a_push_notification_sent", source, event)
-
-        @event_bus.on(A2APushNotificationTimeoutEvent)
-        def on_a2a_push_notification_timeout(
-            source: Any, event: A2APushNotificationTimeoutEvent
-        ) -> None:
-            self._handle_action_event("a2a_push_notification_timeout", source, event)
-
-        @event_bus.on(A2AStreamingStartedEvent)
-        def on_a2a_streaming_started(
-            source: Any, event: A2AStreamingStartedEvent
-        ) -> None:
-            self._handle_action_event("a2a_streaming_started", source, event)
-
-        @event_bus.on(A2AStreamingChunkEvent)
-        def on_a2a_streaming_chunk(source: Any, event: A2AStreamingChunkEvent) -> None:
-            self._handle_action_event("a2a_streaming_chunk", source, event)
-
-        @event_bus.on(A2AAgentCardFetchedEvent)
-        def on_a2a_agent_card_fetched(
-            source: Any, event: A2AAgentCardFetchedEvent
-        ) -> None:
-            self._handle_action_event("a2a_agent_card_fetched", source, event)
-
-        @event_bus.on(A2AAuthenticationFailedEvent)
-        def on_a2a_authentication_failed(
-            source: Any, event: A2AAuthenticationFailedEvent
-        ) -> None:
-            self._handle_action_event("a2a_authentication_failed", source, event)
-
-        @event_bus.on(A2AArtifactReceivedEvent)
-        def on_a2a_artifact_received(
-            source: Any, event: A2AArtifactReceivedEvent
-        ) -> None:
-            self._handle_action_event("a2a_artifact_received", source, event)
-
-        @event_bus.on(A2AConnectionErrorEvent)
-        def on_a2a_connection_error(
-            source: Any, event: A2AConnectionErrorEvent
-        ) -> None:
-            self._handle_action_event("a2a_connection_error", source, event)
-
-        @event_bus.on(A2AServerTaskStartedEvent)
-        def on_a2a_server_task_started(
-            source: Any, event: A2AServerTaskStartedEvent
-        ) -> None:
-            self._handle_action_event("a2a_server_task_started", source, event)
-
-        @event_bus.on(A2AServerTaskCompletedEvent)
-        def on_a2a_server_task_completed(
-            source: Any, event: A2AServerTaskCompletedEvent
-        ) -> None:
-            self._handle_action_event("a2a_server_task_completed", source, event)
-
-        @event_bus.on(A2AServerTaskCanceledEvent)
-        def on_a2a_server_task_canceled(
-            source: Any, event: A2AServerTaskCanceledEvent
-        ) -> None:
-            self._handle_action_event("a2a_server_task_canceled", source, event)
-
-        @event_bus.on(A2AServerTaskFailedEvent)
-        def on_a2a_server_task_failed(
-            source: Any, event: A2AServerTaskFailedEvent
-        ) -> None:
-            self._handle_action_event("a2a_server_task_failed", source, event)
-
-        @event_bus.on(A2AParallelDelegationStartedEvent)
-        def on_a2a_parallel_delegation_started(
-            source: Any, event: A2AParallelDelegationStartedEvent
-        ) -> None:
-            self._handle_action_event("a2a_parallel_delegation_started", source, event)
-
-        @event_bus.on(A2AParallelDelegationCompletedEvent)
-        def on_a2a_parallel_delegation_completed(
-            source: Any, event: A2AParallelDelegationCompletedEvent
-        ) -> None:
-            self._handle_action_event(
-                "a2a_parallel_delegation_completed", source, event
-            )
-
    def _register_system_event_handlers(self, event_bus: CrewAIEventsBus) -> None:
        """Register handlers for system signal events (SIGTERM, SIGINT, etc.)."""

@@ -738,15 +570,10 @@ class TraceCollectionListener(BaseEventListener):
        if event_type not in self.complex_events:
            return safe_serialize_to_dict(event)
        if event_type == "task_started":
-            task_name = event.task.name or event.task.description
-            task_display_name = (
-                task_name[:80] + "..." if len(task_name) > 80 else task_name
-            )
            return {
                "task_description": event.task.description,
                "expected_output": event.task.expected_output,
-                "task_name": task_name,
-                "task_display_name": task_display_name,
+                "task_name": event.task.name or event.task.description,
                "context": event.context,
                "agent_role": source.agent.role,
                "task_id": str(event.task.id),
--- a/lib/crewai/src/crewai/events/types/a2a_events.py
+++ b/lib/crewai/src/crewai/events/types/a2a_events.py
@@ -4,120 +4,68 @@ This module defines events emitted during A2A protocol delegation,
 including both single-turn and multiturn conversation flows.
 """

-from __future__ import annotations
-
 from typing import Any, Literal

-from pydantic import model_validator
-
 from crewai.events.base_events import BaseEvent


 class A2AEventBase(BaseEvent):
    """Base class for A2A events with task/agent context."""

-    from_task: Any = None
-    from_agent: Any = None
+    from_task: Any | None = None
+    from_agent: Any | None = None

-    @model_validator(mode="before")
-    @classmethod
-    def extract_task_and_agent_metadata(cls, data: dict[str, Any]) -> dict[str, Any]:
-        """Extract task and agent metadata before validation."""
-        if task := data.get("from_task"):
+    def __init__(self, **data: Any) -> None:
+        """Initialize A2A event, extracting task and agent metadata."""
+        if data.get("from_task"):
+            task = data["from_task"]
            data["task_id"] = str(task.id)
            data["task_name"] = task.name or task.description
-            data.setdefault("source_fingerprint", str(task.id))
-            data.setdefault("source_type", "task")
-            data.setdefault(
-                "fingerprint_metadata",
-                {
-                    "task_id": str(task.id),
-                    "task_name": task.name or task.description,
-                },
-            )
            data["from_task"] = None

-        if agent := data.get("from_agent"):
+        if data.get("from_agent"):
+            agent = data["from_agent"]
            data["agent_id"] = str(agent.id)
            data["agent_role"] = agent.role
-            data.setdefault("source_fingerprint", str(agent.id))
-            data.setdefault("source_type", "agent")
-            data.setdefault(
-                "fingerprint_metadata",
-                {
-                    "agent_id": str(agent.id),
-                    "agent_role": agent.role,
-                },
-            )
            data["from_agent"] = None

-        return data
+        super().__init__(**data)


 class A2ADelegationStartedEvent(A2AEventBase):
    """Event emitted when A2A delegation starts.

    Attributes:
-        endpoint: A2A agent endpoint URL (AgentCard URL).
-        task_description: Task being delegated to the A2A agent.
-        agent_id: A2A agent identifier.
-        context_id: A2A context ID grouping related tasks.
-        is_multiturn: Whether this is part of a multiturn conversation.
-        turn_number: Current turn number (1-indexed, 1 for single-turn).
-        a2a_agent_name: Name of the A2A agent from agent card.
-        agent_card: Full A2A agent card metadata.
-        protocol_version: A2A protocol version being used.
-        provider: Agent provider/organization info from agent card.
-        skill_id: ID of the specific skill being invoked.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        endpoint: A2A agent endpoint URL (AgentCard URL)
+        task_description: Task being delegated to the A2A agent
+        agent_id: A2A agent identifier
+        is_multiturn: Whether this is part of a multiturn conversation
+        turn_number: Current turn number (1-indexed, 1 for single-turn)
    """

    type: str = "a2a_delegation_started"
    endpoint: str
    task_description: str
    agent_id: str
-    context_id: str | None = None
    is_multiturn: bool = False
    turn_number: int = 1
-    a2a_agent_name: str | None = None
-    agent_card: dict[str, Any] | None = None
-    protocol_version: str | None = None
-    provider: dict[str, Any] | None = None
-    skill_id: str | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2ADelegationCompletedEvent(A2AEventBase):
    """Event emitted when A2A delegation completes.

    Attributes:
-        status: Completion status (completed, input_required, failed, etc.).
-        result: Result message if status is completed.
-        error: Error/response message (error for failed, response for input_required).
-        context_id: A2A context ID grouping related tasks.
-        is_multiturn: Whether this is part of a multiturn conversation.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        agent_card: Full A2A agent card metadata.
-        provider: Agent provider/organization info from agent card.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        status: Completion status (completed, input_required, failed, etc.)
+        result: Result message if status is completed
+        error: Error/response message (error for failed, response for input_required)
+        is_multiturn: Whether this is part of a multiturn conversation
    """

    type: str = "a2a_delegation_completed"
    status: str
    result: str | None = None
    error: str | None = None
-    context_id: str | None = None
    is_multiturn: bool = False
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    agent_card: dict[str, Any] | None = None
-    provider: dict[str, Any] | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2AConversationStartedEvent(A2AEventBase):
@@ -127,95 +75,51 @@ class A2AConversationStartedEvent(A2AEventBase):
    before the first message exchange.

    Attributes:
-        agent_id: A2A agent identifier.
-        endpoint: A2A agent endpoint URL.
-        context_id: A2A context ID grouping related tasks.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        agent_card: Full A2A agent card metadata.
-        protocol_version: A2A protocol version being used.
-        provider: Agent provider/organization info from agent card.
-        skill_id: ID of the specific skill being invoked.
-        reference_task_ids: Related task IDs for context.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        agent_id: A2A agent identifier
+        endpoint: A2A agent endpoint URL
+        a2a_agent_name: Name of the A2A agent from agent card
    """

    type: str = "a2a_conversation_started"
    agent_id: str
    endpoint: str
-    context_id: str | None = None
    a2a_agent_name: str | None = None
-    agent_card: dict[str, Any] | None = None
-    protocol_version: str | None = None
-    provider: dict[str, Any] | None = None
-    skill_id: str | None = None
-    reference_task_ids: list[str] | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2AMessageSentEvent(A2AEventBase):
    """Event emitted when a message is sent to the A2A agent.

    Attributes:
-        message: Message content sent to the A2A agent.
-        turn_number: Current turn number (1-indexed).
-        context_id: A2A context ID grouping related tasks.
-        message_id: Unique A2A message identifier.
-        is_multiturn: Whether this is part of a multiturn conversation.
-        agent_role: Role of the CrewAI agent sending the message.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        skill_id: ID of the specific skill being invoked.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        message: Message content sent to the A2A agent
+        turn_number: Current turn number (1-indexed)
+        is_multiturn: Whether this is part of a multiturn conversation
+        agent_role: Role of the CrewAI agent sending the message
    """

    type: str = "a2a_message_sent"
    message: str
    turn_number: int
-    context_id: str | None = None
-    message_id: str | None = None
    is_multiturn: bool = False
    agent_role: str | None = None
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    skill_id: str | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2AResponseReceivedEvent(A2AEventBase):
    """Event emitted when a response is received from the A2A agent.

    Attributes:
-        response: Response content from the A2A agent.
-        turn_number: Current turn number (1-indexed).
-        context_id: A2A context ID grouping related tasks.
-        message_id: Unique A2A message identifier.
-        is_multiturn: Whether this is part of a multiturn conversation.
-        status: Response status (input_required, completed, etc.).
-        final: Whether this is the final response in the stream.
-        agent_role: Role of the CrewAI agent (for display).
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        response: Response content from the A2A agent
+        turn_number: Current turn number (1-indexed)
+        is_multiturn: Whether this is part of a multiturn conversation
+        status: Response status (input_required, completed, etc.)
+        agent_role: Role of the CrewAI agent (for display)
    """

    type: str = "a2a_response_received"
    response: str
    turn_number: int
-    context_id: str | None = None
-    message_id: str | None = None
    is_multiturn: bool = False
    status: str
-    final: bool = False
    agent_role: str | None = None
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2AConversationCompletedEvent(A2AEventBase):
@@ -224,433 +128,119 @@ class A2AConversationCompletedEvent(A2AEventBase):
    This is emitted once at the end of a multiturn conversation.

    Attributes:
-        status: Final status (completed, failed, etc.).
-        final_result: Final result if completed successfully.
-        error: Error message if failed.
-        context_id: A2A context ID grouping related tasks.
-        total_turns: Total number of turns in the conversation.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        agent_card: Full A2A agent card metadata.
-        reference_task_ids: Related task IDs for context.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
+        status: Final status (completed, failed, etc.)
+        final_result: Final result if completed successfully
+        error: Error message if failed
+        total_turns: Total number of turns in the conversation
    """

    type: str = "a2a_conversation_completed"
    status: Literal["completed", "failed"]
    final_result: str | None = None
    error: str | None = None
-    context_id: str | None = None
    total_turns: int
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    agent_card: dict[str, Any] | None = None
-    reference_task_ids: list[str] | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None


 class A2APollingStartedEvent(A2AEventBase):
    """Event emitted when polling mode begins for A2A delegation.

    Attributes:
-        task_id: A2A task ID being polled.
-        context_id: A2A context ID grouping related tasks.
-        polling_interval: Seconds between poll attempts.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
+        task_id: A2A task ID being polled
+        polling_interval: Seconds between poll attempts
+        endpoint: A2A agent endpoint URL
    """

    type: str = "a2a_polling_started"
    task_id: str
-    context_id: str | None = None
    polling_interval: float
    endpoint: str
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None


 class A2APollingStatusEvent(A2AEventBase):
    """Event emitted on each polling iteration.

    Attributes:
-        task_id: A2A task ID being polled.
-        context_id: A2A context ID grouping related tasks.
-        state: Current task state from remote agent.
-        elapsed_seconds: Time since polling started.
-        poll_count: Number of polls completed.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
+        task_id: A2A task ID being polled
+        state: Current task state from remote agent
+        elapsed_seconds: Time since polling started
+        poll_count: Number of polls completed
    """

    type: str = "a2a_polling_status"
    task_id: str
-    context_id: str | None = None
    state: str
    elapsed_seconds: float
    poll_count: int
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None


 class A2APushNotificationRegisteredEvent(A2AEventBase):
    """Event emitted when push notification callback is registered.

    Attributes:
-        task_id: A2A task ID for which callback is registered.
-        context_id: A2A context ID grouping related tasks.
-        callback_url: URL where agent will send push notifications.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
+        task_id: A2A task ID for which callback is registered
+        callback_url: URL where agent will send push notifications
    """

    type: str = "a2a_push_notification_registered"
    task_id: str
-    context_id: str | None = None
    callback_url: str
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None


 class A2APushNotificationReceivedEvent(A2AEventBase):
    """Event emitted when a push notification is received.

-    This event should be emitted by the user's webhook handler when it receives
-    a push notification from the remote A2A agent, before calling
-    `result_store.store_result()`.
-
    Attributes:
-        task_id: A2A task ID from the notification.
-        context_id: A2A context ID grouping related tasks.
-        state: Current task state from the notification.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
+        task_id: A2A task ID from the notification
+        state: Current task state from the notification
    """

    type: str = "a2a_push_notification_received"
    task_id: str
-    context_id: str | None = None
    state: str
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None
-
-
-class A2APushNotificationSentEvent(A2AEventBase):
-    """Event emitted when a push notification is sent to a callback URL.
-
-    Emitted by the A2A server when it sends a task status update to the
-    client's registered push notification callback URL.
-
-    Attributes:
-        task_id: A2A task ID being notified.
-        context_id: A2A context ID grouping related tasks.
-        callback_url: URL the notification was sent to.
-        state: Task state being reported.
-        success: Whether the notification was successfully delivered.
-        error: Error message if delivery failed.
-        metadata: Custom A2A metadata key-value pairs.
-    """
-
-    type: str = "a2a_push_notification_sent"
-    task_id: str
-    context_id: str | None = None
-    callback_url: str
-    state: str
-    success: bool = True
-    error: str | None = None
-    metadata: dict[str, Any] | None = None


 class A2APushNotificationTimeoutEvent(A2AEventBase):
    """Event emitted when push notification wait times out.

    Attributes:
-        task_id: A2A task ID that timed out.
-        context_id: A2A context ID grouping related tasks.
-        timeout_seconds: Timeout duration in seconds.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        metadata: Custom A2A metadata key-value pairs.
+        task_id: A2A task ID that timed out
+        timeout_seconds: Timeout duration in seconds
    """

    type: str = "a2a_push_notification_timeout"
    task_id: str
-    context_id: str | None = None
    timeout_seconds: float
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    metadata: dict[str, Any] | None = None
-
-
-class A2AStreamingStartedEvent(A2AEventBase):
-    """Event emitted when streaming mode begins for A2A delegation.
-
-    Attributes:
-        task_id: A2A task ID for the streaming session.
-        context_id: A2A context ID grouping related tasks.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        turn_number: Current turn number (1-indexed).
-        is_multiturn: Whether this is part of a multiturn conversation.
-        agent_role: Role of the CrewAI agent.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
-    """
-
-    type: str = "a2a_streaming_started"
-    task_id: str | None = None
-    context_id: str | None = None
-    endpoint: str
-    a2a_agent_name: str | None = None
-    turn_number: int = 1
-    is_multiturn: bool = False
-    agent_role: str | None = None
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None
-
-
-class A2AStreamingChunkEvent(A2AEventBase):
-    """Event emitted when a streaming chunk is received.
-
-    Attributes:
-        task_id: A2A task ID for the streaming session.
-        context_id: A2A context ID grouping related tasks.
-        chunk: The text content of the chunk.
-        chunk_index: Index of this chunk in the stream (0-indexed).
-        final: Whether this is the final chunk in the stream.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        turn_number: Current turn number (1-indexed).
-        is_multiturn: Whether this is part of a multiturn conversation.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
-    """
-
-    type: str = "a2a_streaming_chunk"
-    task_id: str | None = None
-    context_id: str | None = None
-    chunk: str
-    chunk_index: int
-    final: bool = False
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    turn_number: int = 1
-    is_multiturn: bool = False
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None
-
-
-class A2AAgentCardFetchedEvent(A2AEventBase):
-    """Event emitted when an agent card is successfully fetched.
-
-    Attributes:
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        agent_card: Full A2A agent card metadata.
-        protocol_version: A2A protocol version from agent card.
-        provider: Agent provider/organization info from agent card.
-        cached: Whether the agent card was retrieved from cache.
-        fetch_time_ms: Time taken to fetch the agent card in milliseconds.
-        metadata: Custom A2A metadata key-value pairs.
-    """
-
-    type: str = "a2a_agent_card_fetched"
-    endpoint: str
-    a2a_agent_name: str | None = None
-    agent_card: dict[str, Any] | None = None
-    protocol_version: str | None = None
-    provider: dict[str, Any] | None = None
-    cached: bool = False
-    fetch_time_ms: float | None = None
-    metadata: dict[str, Any] | None = None
-
-
-class A2AAuthenticationFailedEvent(A2AEventBase):
-    """Event emitted when authentication to an A2A agent fails.
-
-    Attributes:
-        endpoint: A2A agent endpoint URL.
-        auth_type: Type of authentication attempted (e.g., bearer, oauth2, api_key).
-        error: Error message describing the failure.
-        status_code: HTTP status code if applicable.
-        a2a_agent_name: Name of the A2A agent if known.
-        protocol_version: A2A protocol version being used.
-        metadata: Custom A2A metadata key-value pairs.
-    """
-
-    type: str = "a2a_authentication_failed"
-    endpoint: str
-    auth_type: str | None = None
-    error: str
-    status_code: int | None = None
-    a2a_agent_name: str | None = None
-    protocol_version: str | None = None
-    metadata: dict[str, Any] | None = None
-
-
-class A2AArtifactReceivedEvent(A2AEventBase):
-    """Event emitted when an artifact is received from a remote A2A agent.
-
-    Attributes:
-        task_id: A2A task ID the artifact belongs to.
-        artifact_id: Unique identifier for the artifact.
-        artifact_name: Name of the artifact.
-        artifact_description: Purpose description of the artifact.
-        mime_type: MIME type of the artifact content.
-        size_bytes: Size of the artifact in bytes.
-        append: Whether content should be appended to existing artifact.
-        last_chunk: Whether this is the final chunk of the artifact.
-        endpoint: A2A agent endpoint URL.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        context_id: Context ID for correlation.
-        turn_number: Current turn number (1-indexed).
-        is_multiturn: Whether this is part of a multiturn conversation.
-        metadata: Custom A2A metadata key-value pairs.
-        extensions: List of A2A extension URIs in use.
-    """
-
-    type: str = "a2a_artifact_received"
-    task_id: str
-    artifact_id: str
-    artifact_name: str | None = None
-    artifact_description: str | None = None
-    mime_type: str | None = None
-    size_bytes: int | None = None
-    append: bool = False
-    last_chunk: bool = False
-    endpoint: str | None = None
-    a2a_agent_name: str | None = None
-    context_id: str | None = None
-    turn_number: int = 1
-    is_multiturn: bool = False
-    metadata: dict[str, Any] | None = None
-    extensions: list[str] | None = None
-
-
-class A2AConnectionErrorEvent(A2AEventBase):
-    """Event emitted when a connection error occurs during A2A communication.
-
-    Attributes:
-        endpoint: A2A agent endpoint URL.
-        error: Error message describing the connection failure.
-        error_type: Type of error (e.g., timeout, connection_refused, dns_error).
-        status_code: HTTP status code if applicable.
-        a2a_agent_name: Name of the A2A agent from agent card.
-        operation: The operation being attempted when error occurred.
-        context_id: A2A context ID grouping related tasks.
-        task_id: A2A task ID if applicable.
-        metadata: Custom A2A metadata key-value pairs.
-    """
-
-    type: str = "a2a_connection_error"
-    endpoint: str
-    error: str
-    error_type: str | None = None
-    status_code: int | None = None
-    a2a_agent_name: str | None = None
-    operation: str | None = None
-    context_id: str | None = None
-    task_id: str | None = None
-    metadata: dict[str, Any] | None = None


 class A2AServerTaskStartedEvent(A2AEventBase):
-    """Event emitted when an A2A server task execution starts.
-
-    Attributes:
-        task_id: A2A task ID for this execution.
-        context_id: A2A context ID grouping related tasks.
-        metadata: Custom A2A metadata key-value pairs.
-    """
+    """Event emitted when an A2A server task execution starts."""

    type: str = "a2a_server_task_started"
-    task_id: str
-    context_id: str
-    metadata: dict[str, Any] | None = None
+    a2a_task_id: str
+    a2a_context_id: str


 class A2AServerTaskCompletedEvent(A2AEventBase):
-    """Event emitted when an A2A server task execution completes.
-
-    Attributes:
-        task_id: A2A task ID for this execution.
-        context_id: A2A context ID grouping related tasks.
-        result: The task result.
-        metadata: Custom A2A metadata key-value pairs.
-    """
+    """Event emitted when an A2A server task execution completes."""

    type: str = "a2a_server_task_completed"
-    task_id: str
-    context_id: str
+    a2a_task_id: str
+    a2a_context_id: str
    result: str
-    metadata: dict[str, Any] | None = None


 class A2AServerTaskCanceledEvent(A2AEventBase):
-    """Event emitted when an A2A server task execution is canceled.
-
-    Attributes:
-        task_id: A2A task ID for this execution.
-        context_id: A2A context ID grouping related tasks.
-        metadata: Custom A2A metadata key-value pairs.
-    """
+    """Event emitted when an A2A server task execution is canceled."""

    type: str = "a2a_server_task_canceled"
-    task_id: str
-    context_id: str
-    metadata: dict[str, Any] | None = None
+    a2a_task_id: str
+    a2a_context_id: str


 class A2AServerTaskFailedEvent(A2AEventBase):
-    """Event emitted when an A2A server task execution fails.
-
-    Attributes:
-        task_id: A2A task ID for this execution.
-        context_id: A2A context ID grouping related tasks.
-        error: Error message describing the failure.
-        metadata: Custom A2A metadata key-value pairs.
-    """
+    """Event emitted when an A2A server task execution fails."""

    type: str = "a2a_server_task_failed"
-    task_id: str
-    context_id: str
+    a2a_task_id: str
+    a2a_context_id: str
    error: str
-    metadata: dict[str, Any] | None = None
-
-
-class A2AParallelDelegationStartedEvent(A2AEventBase):
-    """Event emitted when parallel delegation to multiple A2A agents begins.
-
-    Attributes:
-        endpoints: List of A2A agent endpoints being delegated to.
-        task_description: Description of the task being delegated.
-    """
-
-    type: str = "a2a_parallel_delegation_started"
-    endpoints: list[str]
-    task_description: str
-
-
-class A2AParallelDelegationCompletedEvent(A2AEventBase):
-    """Event emitted when parallel delegation to multiple A2A agents completes.
-
-    Attributes:
-        endpoints: List of A2A agent endpoints that were delegated to.
-        success_count: Number of successful delegations.
-        failure_count: Number of failed delegations.
-        results: Summary of results from each agent.
-    """
-
-    type: str = "a2a_parallel_delegation_completed"
-    endpoints: list[str]
-    success_count: int
-    failure_count: int
-    results: dict[str, str] | None = None
--- a/lib/crewai/src/crewai/llms/providers/gemini/completion.py
+++ b/lib/crewai/src/crewai/llms/providers/gemini/completion.py
@@ -54,15 +54,21 @@ class GeminiCompletion(BaseLLM):
        safety_settings: dict[str, Any] | None = None,
        client_params: dict[str, Any] | None = None,
        interceptor: BaseInterceptor[Any, Any] | None = None,
+        use_vertexai: bool | None = None,
        **kwargs: Any,
    ):
        """Initialize Google Gemini chat completion client.

        Args:
            model: Gemini model name (e.g., 'gemini-2.0-flash-001', 'gemini-1.5-pro')
-            api_key: Google API key (defaults to GOOGLE_API_KEY or GEMINI_API_KEY env var)
-            project: Google Cloud project ID (for Vertex AI)
-            location: Google Cloud location (for Vertex AI, defaults to 'us-central1')
+            api_key: Google API key for Gemini API authentication.
+                    Defaults to GOOGLE_API_KEY or GEMINI_API_KEY env var.
+                    NOTE: Cannot be used with Vertex AI (project parameter). Use Gemini API instead.
+            project: Google Cloud project ID for Vertex AI with ADC authentication.
+                    Requires Application Default Credentials (gcloud auth application-default login).
+                    NOTE: Vertex AI does NOT support API keys, only OAuth2/ADC.
+                    If both api_key and project are set, api_key takes precedence.
+            location: Google Cloud location (for Vertex AI with ADC, defaults to 'us-central1')
            temperature: Sampling temperature (0-2)
            top_p: Nucleus sampling parameter
            top_k: Top-k sampling parameter
@@ -73,6 +79,12 @@ class GeminiCompletion(BaseLLM):
            client_params: Additional parameters to pass to the Google Gen AI Client constructor.
                          Supports parameters like http_options, credentials, debug_config, etc.
            interceptor: HTTP interceptor (not yet supported for Gemini).
+            use_vertexai: Whether to use Vertex AI instead of Gemini API.
+                         - True: Use Vertex AI (with ADC or Express mode with API key)
+                         - False: Use Gemini API (explicitly override env var)
+                         - None (default): Check GOOGLE_GENAI_USE_VERTEXAI env var
+                         When using Vertex AI with API key (Express mode), http_options with
+                         api_version="v1" is automatically configured.
            **kwargs: Additional parameters
        """
        if interceptor is not None:
@@ -95,7 +107,8 @@ class GeminiCompletion(BaseLLM):
        self.project = project or os.getenv("GOOGLE_CLOUD_PROJECT")
        self.location = location or os.getenv("GOOGLE_CLOUD_LOCATION") or "us-central1"

-        use_vertexai = os.getenv("GOOGLE_GENAI_USE_VERTEXAI", "").lower() == "true"
+        if use_vertexai is None:
+            use_vertexai = os.getenv("GOOGLE_GENAI_USE_VERTEXAI", "").lower() == "true"

        self.client = self._initialize_client(use_vertexai)

@@ -146,13 +159,34 @@ class GeminiCompletion(BaseLLM):

        Returns:
            Initialized Google Gen AI Client
+
+        Note:
+            Google Gen AI SDK has two distinct endpoints with different auth requirements:
+            - Gemini API (generativelanguage.googleapis.com): Supports API key authentication
+            - Vertex AI (aiplatform.googleapis.com): Only supports OAuth2/ADC, NO API keys
+
+            When vertexai=True is set, it routes to aiplatform.googleapis.com which rejects
+            API keys. Use Gemini API endpoint for API key authentication instead.
        """
        client_params = {}

        if self.client_params:
            client_params.update(self.client_params)

-        if use_vertexai or self.project:
+        # Determine authentication mode based on available credentials
+        has_api_key = bool(self.api_key)
+        has_project = bool(self.project)
+
+        if has_api_key and has_project:
+            logging.warning(
+                "Both API key and project provided. Using API key authentication. "
+                "Project/location parameters are ignored when using API keys. "
+                "To use Vertex AI with ADC, remove the api_key parameter."
+            )
+            has_project = False
+
+        # Vertex AI with ADC (project without API key)
+        if (use_vertexai or has_project) and not has_api_key:
            client_params.update(
                {
                    "vertexai": True,
@@ -161,12 +195,20 @@ class GeminiCompletion(BaseLLM):
                }
            )

-            client_params.pop("api_key", None)
-
-        elif self.api_key:
+        # API key authentication (works with both Gemini API and Vertex AI Express)
+        elif has_api_key:
            client_params["api_key"] = self.api_key

-            client_params.pop("vertexai", None)
+            # Vertex AI Express mode: API key + vertexai=True + http_options with api_version="v1"
+            # See: https://cloud.google.com/vertex-ai/generative-ai/docs/start/quickstart?usertype=apikey
+            if use_vertexai:
+                client_params["vertexai"] = True
+                client_params["http_options"] = types.HttpOptions(api_version="v1")
+            else:
+                # This ensures we use the Gemini API (generativelanguage.googleapis.com)
+                client_params["vertexai"] = False
+
+            # Clean up project/location (not allowed with API key)
            client_params.pop("project", None)
            client_params.pop("location", None)

@@ -175,10 +217,13 @@ class GeminiCompletion(BaseLLM):
                return genai.Client(**client_params)
            except Exception as e:
                raise ValueError(
-                    "Either GOOGLE_API_KEY/GEMINI_API_KEY (for Gemini API) or "
-                    "GOOGLE_CLOUD_PROJECT (for Vertex AI) must be set"
+                    "Authentication required. Provide one of:\n"
+                    "  1. API key via GOOGLE_API_KEY or GEMINI_API_KEY environment variable\n"
+                    "     (use_vertexai=True is optional for Vertex AI with API key)\n"
+                    "  2. For Vertex AI with ADC: Set GOOGLE_CLOUD_PROJECT and run:\n"
+                    "     gcloud auth application-default login\n"
+                    "  3. Pass api_key parameter directly to LLM constructor\n"
                ) from e
-
        return genai.Client(**client_params)

    def _get_client_params(self) -> dict[str, Any]:
@@ -202,6 +247,8 @@ class GeminiCompletion(BaseLLM):
                    "location": self.location,
                }
            )
+            if self.api_key:
+                params["api_key"] = self.api_key
        elif self.api_key:
            params["api_key"] = self.api_key

--- a/lib/crewai/tests/a2a/utils/test_task.py
+++ b/lib/crewai/tests/a2a/utils/test_task.py
@@ -26,13 +26,9 @@ def mock_agent() -> MagicMock:


@pytest.fixture
-def mock_task(mock_context: MagicMock) -> MagicMock:
+def mock_task() -> MagicMock:
    """Create a mock Task."""
-    task = MagicMock()
-    task.id = mock_context.task_id
-    task.name = "Mock Task"
-    task.description = "Mock task description"
-    return task
+    return MagicMock()


@pytest.fixture
@@ -183,8 +179,8 @@ class TestExecute:
        event = first_call[0][1]

        assert event.type == "a2a_server_task_started"
-        assert event.task_id == mock_context.task_id
-        assert event.context_id == mock_context.context_id
+        assert event.a2a_task_id == mock_context.task_id
+        assert event.a2a_context_id == mock_context.context_id

    @pytest.mark.asyncio
    async def test_emits_completed_event(
@@ -205,7 +201,7 @@ class TestExecute:
        event = second_call[0][1]

        assert event.type == "a2a_server_task_completed"
-        assert event.task_id == mock_context.task_id
+        assert event.a2a_task_id == mock_context.task_id
        assert event.result == "Task completed successfully"

    @pytest.mark.asyncio
@@ -254,7 +250,7 @@ class TestExecute:
        event = canceled_call[0][1]

        assert event.type == "a2a_server_task_canceled"
-        assert event.task_id == mock_context.task_id
+        assert event.a2a_task_id == mock_context.task_id


 class TestCancel:
--- a/lib/crewai/tests/agents/test_a2a_trust_completion_status.py
+++ b/lib/crewai/tests/agents/test_a2a_trust_completion_status.py
@@ -14,16 +14,6 @@ except ImportError:
    A2A_SDK_INSTALLED = False


-def _create_mock_agent_card(name: str = "Test", url: str = "http://test-endpoint.com/"):
-    """Create a mock agent card with proper model_dump behavior."""
-    mock_card = MagicMock()
-    mock_card.name = name
-    mock_card.url = url
-    mock_card.model_dump.return_value = {"name": name, "url": url}
-    mock_card.model_dump_json.return_value = f'{{"name": "{name}", "url": "{url}"}}'
-    return mock_card
-
-
@pytest.mark.skipif(not A2A_SDK_INSTALLED, reason="Requires a2a-sdk to be installed")
 def test_trust_remote_completion_status_true_returns_directly():
    """When trust_remote_completion_status=True and A2A returns completed, return result directly."""
@@ -54,7 +44,8 @@ def test_trust_remote_completion_status_true_returns_directly():
        patch("crewai.a2a.wrapper.execute_a2a_delegation") as mock_execute,
        patch("crewai.a2a.wrapper._fetch_agent_cards_concurrently") as mock_fetch,
    ):
-        mock_card = _create_mock_agent_card()
+        mock_card = MagicMock()
+        mock_card.name = "Test"
        mock_fetch.return_value = ({"http://test-endpoint.com/": mock_card}, {})

        # A2A returns completed
@@ -119,7 +110,8 @@ def test_trust_remote_completion_status_false_continues_conversation():
        patch("crewai.a2a.wrapper.execute_a2a_delegation") as mock_execute,
        patch("crewai.a2a.wrapper._fetch_agent_cards_concurrently") as mock_fetch,
    ):
-        mock_card = _create_mock_agent_card()
+        mock_card = MagicMock()
+        mock_card.name = "Test"
        mock_fetch.return_value = ({"http://test-endpoint.com/": mock_card}, {})

        # A2A returns completed
--- a/lib/crewai/tests/cassettes/llms/google/test_google_express_mode_works.yaml
+++ b/lib/crewai/tests/cassettes/llms/google/test_google_express_mode_works.yaml
@@ -0,0 +1,75 @@
+interactions:
+- request:
+    body: '{"contents": [{"parts": [{"text": "\nCurrent Task: What is the capital
+      of Japan?\n\nThis is the expected criteria for your final answer: The capital
+      of Japan\nyou MUST return the actual complete content as the final answer, not
+      a summary.\n\nBegin! This is VERY important to you, use the tools available
+      and give your best Final Answer, your job depends on it!\n\nThought:"}], "role":
+      "user"}], "systemInstruction": {"parts": [{"text": "You are Research Assistant.
+      You are a helpful research assistant.\nYour personal goal is: Find information
+      about the capital of Japan\nTo give my best complete final answer to the task
+      respond using the exact following format:\n\nThought: I now can give a great
+      answer\nFinal Answer: Your final answer must be the great and the most complete
+      as possible, it must be outcome described.\n\nI MUST use these formats, my job
+      depends on it!"}], "role": "user"}, "generationConfig": {"stopSequences": ["\nObservation:"]}}'
+    headers:
+      User-Agent:
+      - X-USER-AGENT-XXX
+      accept:
+      - '*/*'
+      accept-encoding:
+      - ACCEPT-ENCODING-XXX
+      connection:
+      - keep-alive
+      content-length:
+      - '952'
+      content-type:
+      - application/json
+      host:
+      - aiplatform.googleapis.com
+      x-goog-api-client:
+      - google-genai-sdk/1.59.0 gl-python/3.13.3
+      x-goog-api-key:
+      - X-GOOG-API-KEY-XXX
+    method: POST
+    uri: https://aiplatform.googleapis.com/v1/publishers/google/models/gemini-2.0-flash-exp:generateContent
+  response:
+    body:
+      string: "{\n  \"candidates\": [\n    {\n      \"content\": {\n        \"role\":
+        \"model\",\n        \"parts\": [\n          {\n            \"text\": \"The
+        capital of Japan is Tokyo.\\nFinal Answer: Tokyo\\n\"\n          }\n        ]\n
+        \     },\n      \"finishReason\": \"STOP\",\n      \"avgLogprobs\": -0.017845841554495003\n
+        \   }\n  ],\n  \"usageMetadata\": {\n    \"promptTokenCount\": 163,\n    \"candidatesTokenCount\":
+        13,\n    \"totalTokenCount\": 176,\n    \"trafficType\": \"ON_DEMAND\",\n
+        \   \"promptTokensDetails\": [\n      {\n        \"modality\": \"TEXT\",\n
+        \       \"tokenCount\": 163\n      }\n    ],\n    \"candidatesTokensDetails\":
+        [\n      {\n        \"modality\": \"TEXT\",\n        \"tokenCount\": 13\n
+        \     }\n    ]\n  },\n  \"modelVersion\": \"gemini-2.0-flash-exp\",\n  \"createTime\":
+        \"2026-01-15T22:27:38.066749Z\",\n  \"responseId\": \"2mlpab2JBNOFidsPh5GigQs\"\n}\n"
+    headers:
+      Alt-Svc:
+      - h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
+      Content-Type:
+      - application/json; charset=UTF-8
+      Date:
+      - Thu, 15 Jan 2026 22:27:38 GMT
+      Server:
+      - scaffolding on HTTPServer2
+      Transfer-Encoding:
+      - chunked
+      Vary:
+      - Origin
+      - X-Origin
+      - Referer
+      X-Content-Type-Options:
+      - X-CONTENT-TYPE-XXX
+      X-Frame-Options:
+      - X-FRAME-OPTIONS-XXX
+      X-XSS-Protection:
+      - '0'
+      content-length:
+      - '786'
+    status:
+      code: 200
+      message: OK
+version: 1
--- a/lib/crewai/tests/llms/google/test_google.py
+++ b/lib/crewai/tests/llms/google/test_google.py
@@ -728,3 +728,39 @@ def test_google_streaming_returns_usage_metrics():
    assert result.token_usage.prompt_tokens > 0
    assert result.token_usage.completion_tokens > 0
    assert result.token_usage.successful_requests >= 1
+
+
+@pytest.mark.vcr()
+def test_google_express_mode_works() -> None:
+    """
+    Test Google Vertex AI Express mode with API key authentication.
+    This tests Vertex AI Express mode (aiplatform.googleapis.com) with API key
+    authentication.
+
+    """
+    with patch.dict(os.environ, {"GOOGLE_GENAI_USE_VERTEXAI": "true"}):
+        agent = Agent(
+            role="Research Assistant",
+            goal="Find information about the capital of Japan",
+            backstory="You are a helpful research assistant.",
+            llm=LLM(
+                model="gemini/gemini-2.0-flash-exp",
+            ),
+            verbose=True,
+        )
+
+        task = Task(
+            description="What is the capital of Japan?",
+            expected_output="The capital of Japan",
+            agent=agent,
+        )
+
+
+        crew = Crew(agents=[agent], tasks=[task])
+        result = crew.kickoff()
+
+        assert result.token_usage is not None
+        assert result.token_usage.total_tokens > 0
+        assert result.token_usage.prompt_tokens > 0
+        assert result.token_usage.completion_tokens > 0
+        assert result.token_usage.successful_requests >= 1
Author	SHA1	Message	Date
lorenzejay	e83b7554bf	docs translations	2026-01-15 14:43:43 -08:00
lorenzejay	7834b07ce4	Merge branch 'main' of github.com:crewAIInc/crewAI into lorenze/fix-google-vertex-api-using-api-keys	2026-01-15 14:37:37 -08:00
lorenzejay	a9bb03ffa8	docs update here	2026-01-15 14:37:16 -08:00
lorenzejay	5beaea189b	supporting vertex through api key use - expo mode	2026-01-15 14:34:07 -08:00