feat(a2a): upgrade a2a-sdk from >=0.3.4,<0.4 to >=1.0,<2 (A2A 1.0 spec)

pyproject.toml

@@ -62,7 +62,7 @@ dependencies = [
 ]
 
 optional-dependencies.a2a = [
-  "a2a-sdk>=0.3.4,<0.4",
+  "a2a-sdk>=1.0,<2",
 ]
 optional-dependencies.agent-identity = [
   "google-cloud-iamconnectorcredentials>=0.1,<0.2",
@@ -179,7 +179,7 @@ optional-dependencies.mcp = [
 optional-dependencies.otel-gcp = [ "opentelemetry-instrumentation-google-genai>=0.6b0,<1" ]
 optional-dependencies.slack = [ "slack-bolt>=1.22" ]
 optional-dependencies.test = [
-  "a2a-sdk>=0.3,<0.4",
+  "a2a-sdk>=1.0,<2",
   "anthropic>=0.78",                                                 # For anthropic model tests; 0.78 introduced ThinkingConfigAdaptiveParam (required for Claude Opus 4.7).
   "anyio>=4.9,<5",
   "crewai[tools]; python_version>='3.11' and python_version<'3.12'", # For CrewaiTool tests; chromadb/pypika fail on 3.12+

src/google/adk/a2a/agent/config.py

@@ -23,7 +23,7 @@
 from typing import Optional
 from typing import Union
 
-from a2a.client.middleware import ClientCallContext
+from a2a.client.client import ClientCallContext
 from a2a.server.events import Event as A2AEvent
 from a2a.types import Message as A2AMessage
 from pydantic import BaseModel

src/google/adk/a2a/agent/interceptors/new_integration_extension.py

@@ -17,7 +17,7 @@
 
 from typing import Union
 
-from a2a.client.middleware import ClientCallContext
+from a2a.client.client import ClientCallContext
 from a2a.extensions.common import HTTP_EXTENSION_HEADER
 from a2a.types import Message as A2AMessage
 from google.adk.a2a.agent.config import ParametersConfig

src/google/adk/a2a/agent/utils.py

@@ -19,9 +19,9 @@
 from typing import Optional
 from typing import Union
 
-from a2a.client import ClientEvent as A2AClientEvent
-from a2a.client.middleware import ClientCallContext
+from a2a.client.client import ClientCallContext
 from a2a.types import Message as A2AMessage
+from a2a.types import StreamResponse as A2AStreamResponse
 
 from ...agents.invocation_context import InvocationContext
 from ...events.event import Event
@@ -57,7 +57,7 @@ async def execute_before_request_interceptors(
 async def execute_after_request_interceptors(
     request_interceptors: Optional[list[RequestInterceptor]],
     ctx: InvocationContext,
-    a2a_response: A2AMessage | A2AClientEvent,
+    a2a_response: A2AMessage | A2AStreamResponse,
     event: Event,
 ) -> Optional[Event]:
   """Executes registered after_request interceptors."""

src/google/adk/a2a/converters/event_converter.py

@@ -24,15 +24,13 @@
 from typing import Optional
 
 from a2a.server.events import Event as A2AEvent
-from a2a.types import DataPart
 from a2a.types import Message
 from a2a.types import Part as A2APart
 from a2a.types import Role
 from a2a.types import Task
 from a2a.types import TaskState
 from a2a.types import TaskStatus
 from a2a.types import TaskStatusUpdateEvent
-from a2a.types import TextPart
 from google.adk.platform import time as platform_time
 from google.adk.platform import uuid as platform_uuid
 from google.genai import types as genai_types
@@ -45,6 +43,7 @@
 from .part_converter import A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
 from .part_converter import A2A_DATA_PART_METADATA_TYPE_KEY
 from .part_converter import A2APartToGenAIPartConverter
+from .part_converter import _part_data_as_dict
 from .part_converter import convert_a2a_part_to_genai_part
 from .part_converter import convert_genai_part_to_a2a_part
 from .part_converter import GenAIPartToA2APartConverter
@@ -185,16 +184,14 @@ def _process_long_running_tool(a2a_part: A2APart, event: Event) -> None:
     event: The ADK event containing long-running tool information.
   """
   if (
-      isinstance(a2a_part.root, DataPart)
+      a2a_part.WhichOneof("content") == "data"
       and event.long_running_tool_ids
-      and a2a_part.root.metadata
-      and a2a_part.root.metadata.get(
-          _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
-      )
+      and _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY) in a2a_part.metadata
+      and a2a_part.metadata[_get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)]
       == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
-      and a2a_part.root.data.get("id") in event.long_running_tool_ids
+      and _part_data_as_dict(a2a_part).get("id") in event.long_running_tool_ids
   ):
-    a2a_part.root.metadata[
+    a2a_part.metadata[
         _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY)
     ] = True
 
@@ -229,7 +226,7 @@ def convert_a2a_task_to_event(
     message = None
     if a2a_task.artifacts:
       message = Message(
-          message_id="", role=Role.agent, parts=a2a_task.artifacts[-1].parts
+          message_id="", role=Role.ROLE_AGENT, parts=list(a2a_task.artifacts[-1].parts)
       )
     elif (
         a2a_task.status
@@ -321,14 +318,13 @@ def convert_a2a_message_to_event(
           continue
 
         # Check for long-running tools
+        is_long_running_key = _get_adk_metadata_key(
+            A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY
+        )
         if (
-            a2a_part.root.metadata
-            and a2a_part.root.metadata.get(
-                _get_adk_metadata_key(
-                    A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY
-                )
-            )
-            is True
+            a2a_part.metadata
+            and is_long_running_key in a2a_part.metadata
+            and a2a_part.metadata[is_long_running_key] is True
         ):
           for part in parts:
             if part.function_call:
@@ -371,15 +367,13 @@ def convert_a2a_message_to_event(
 @a2a_experimental
 def convert_event_to_a2a_message(
     event: Event,
-    invocation_context: InvocationContext | None = None,
-    role: Role = Role.agent,
+    role: Role = Role.ROLE_AGENT,
     part_converter: GenAIPartToA2APartConverter = convert_genai_part_to_a2a_part,
 ) -> Optional[Message]:
   """Converts an ADK event to an A2A message.
 
   Args:
     event: The ADK event to convert.
-    invocation_context: The invocation context.
     role: The role of the message.
     part_converter: The function to convert GenAI part to A2A part.
 
@@ -441,28 +435,28 @@ def _create_error_status_event(
   if event.error_code:
     event_metadata[_get_adk_metadata_key("error_code")] = str(event.error_code)
 
-  return TaskStatusUpdateEvent(
+  error_msg = Message(
+      message_id=platform_uuid.new_uuid(),
+      role=Role.ROLE_AGENT,
+      parts=[A2APart(text=error_message)],
+  )
+  if event.error_code:
+    error_msg.metadata[_get_adk_metadata_key("error_code")] = str(
+        event.error_code
+    )
+
+  status = TaskStatus(state=TaskState.TASK_STATE_FAILED, message=error_msg)
+  status.timestamp.FromDatetime(
+      datetime.fromtimestamp(platform_time.get_time(), tz=timezone.utc)
+  )
+
+  tsue = TaskStatusUpdateEvent(
       task_id=task_id,
       context_id=context_id,
-      metadata=event_metadata,
-      status=TaskStatus(
-          state=TaskState.failed,
-          message=Message(
-              message_id=platform_uuid.new_uuid(),
-              role=Role.agent,
-              parts=[TextPart(text=error_message)],
-              metadata={
-                  _get_adk_metadata_key("error_code"): str(event.error_code)
-              }
-              if event.error_code
-              else {},
-          ),
-          timestamp=datetime.fromtimestamp(
-              platform_time.get_time(), tz=timezone.utc
-          ).isoformat(),
-      ),
-      final=False,
   )
+  tsue.status.CopyFrom(status)
+  tsue.metadata.update(event_metadata)
+  return tsue
 
 
 def _create_status_update_event(
@@ -484,49 +478,43 @@ def _create_status_update_event(
   Returns:
     A TaskStatusUpdateEvent with RUNNING state.
   """
-  status = TaskStatus(
-      state=TaskState.working,
-      message=message,
-      timestamp=datetime.fromtimestamp(
-          platform_time.get_time(), tz=timezone.utc
-      ).isoformat(),
-  )
+  state = TaskState.TASK_STATE_WORKING
+
+  type_key = _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
+  lr_key = _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY)
 
   if any(
-      part.root.metadata.get(
-          _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
-      )
-      == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
-      and part.root.metadata.get(
-          _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY)
-      )
-      is True
-      and part.root.data.get("name") == REQUEST_EUC_FUNCTION_CALL_NAME
+      type_key in part.metadata
+      and part.metadata[type_key] == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
+      and lr_key in part.metadata
+      and part.metadata[lr_key] is True
+      and _part_data_as_dict(part).get("name") == REQUEST_EUC_FUNCTION_CALL_NAME
       for part in message.parts
-      if part.root.metadata
+      if part.metadata
   ):
-    status.state = TaskState.auth_required
+    state = TaskState.TASK_STATE_AUTH_REQUIRED
   elif any(
-      part.root.metadata.get(
-          _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
-      )
-      == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
-      and part.root.metadata.get(
-          _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY)
-      )
-      is True
+      type_key in part.metadata
+      and part.metadata[type_key] == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
+      and lr_key in part.metadata
+      and part.metadata[lr_key] is True
       for part in message.parts
-      if part.root.metadata
+      if part.metadata
   ):
-    status.state = TaskState.input_required
+    state = TaskState.TASK_STATE_INPUT_REQUIRED
+
+  status = TaskStatus(state=state, message=message)
+  status.timestamp.FromDatetime(
+      datetime.fromtimestamp(platform_time.get_time(), tz=timezone.utc)
+  )
 
-  return TaskStatusUpdateEvent(
+  tsue = TaskStatusUpdateEvent(
       task_id=task_id,
       context_id=context_id,
-      status=status,
-      metadata=_get_context_metadata(event, invocation_context),
-      final=False,
   )
+  tsue.status.CopyFrom(status)
+  tsue.metadata.update(_get_context_metadata(event, invocation_context))
+  return tsue
 
 
 @a2a_experimental
@@ -571,9 +559,8 @@ def convert_event_to_a2a_events(
     # Handle regular message content
     message = convert_event_to_a2a_message(
         event,
-        invocation_context,
+        role=Role.ROLE_USER if event.author == "user" else Role.ROLE_AGENT,
         part_converter=part_converter,
-        role=Role.user if event.author == "user" else Role.agent,
     )
     if message:
       running_event = _create_status_update_event(