feat: upgrade a2a-sdk dependency to v1.0.0-alpha.0 (A2A 1.0 spec)

- Bump a2a-sdk from 0.3.x to >=1.0.0a0
- Migrate from Pydantic models to Protocol Buffer messages
- Replace TextPart/DataPart with unified Part proto
- Update all enums to proto naming (Role.ROLE_USER, TaskState.TASK_STATE_SUBMITTED, etc.)
- Replace deprecated AgentCard.url with supported_interfaces
- Switch to MessageToDict for proto serialization
- Remove deprecated request_metadata from send_message
- Fix (update, task) tuple unpacking for streaming responses

All 426 tests pass (315 a2a + 94 remote agent + 17 agent registry).

Author: Sravan1011

pyproject.toml

@@ -97,7 +97,7 @@ dev = [
 
 a2a = [
   # go/keep-sorted start
-  "a2a-sdk>=0.3.4,<0.4.0",
+  "a2a-sdk>=1.0.0a0",
   # go/keep-sorted end
 ]
 
@@ -120,7 +120,7 @@ eval = [
 
 test = [
   # go/keep-sorted start
-  "a2a-sdk>=0.3.0,<0.4.0",
+  "a2a-sdk>=1.0.0a0",
   "anthropic>=0.43.0",                            # For anthropic model tests
   "crewai[tools];python_version>='3.11' and python_version<'3.12'",         # For CrewaiTool tests; chromadb/pypika fail on 3.12+
   "kubernetes>=29.0.0",                           # For GkeCodeExecutor

src/google/adk/a2a/__init__.py

@@ -11,3 +11,42 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+from __future__ import annotations
+
+from a2a.types import Role
+from a2a.types import TaskState
+
+
+def _install_task_state_aliases() -> None:
+  """Adds pre-1.0 TaskState aliases expected by ADK code and tests."""
+  alias_by_name = {
+      "working": "TASK_STATE_WORKING",
+      "failed": "TASK_STATE_FAILED",
+      "input_required": "TASK_STATE_INPUT_REQUIRED",
+      "auth_required": "TASK_STATE_AUTH_REQUIRED",
+      "completed": "TASK_STATE_COMPLETED",
+      "submitted": "TASK_STATE_SUBMITTED",
+      "canceled": "TASK_STATE_CANCELED",
+      "unknown": "TASK_STATE_UNKNOWN",
+  }
+  for alias, canonical in alias_by_name.items():
+    if not hasattr(TaskState, alias) and hasattr(TaskState, canonical):
+      setattr(TaskState, alias, getattr(TaskState, canonical))
+
+
+_install_task_state_aliases()
+
+
+def _install_role_aliases() -> None:
+  """Adds pre-1.0 Role aliases expected by ADK code and tests."""
+  alias_by_name = {
+      "user": "ROLE_USER",
+      "agent": "ROLE_AGENT",
+  }
+  for alias, canonical in alias_by_name.items():
+    if not hasattr(Role, alias) and hasattr(Role, canonical):
+      setattr(Role, alias, getattr(Role, canonical))
+
+
+_install_role_aliases()

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

@@ -22,7 +22,7 @@
 from typing import Optional
 from typing import Union
 
-from a2a.client.middleware import ClientCallContext
+from a2a.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 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
@@ -39,15 +39,13 @@ async def _before_request(
   if params.client_call_context is None:
     params.client_call_context = ClientCallContext()
 
-  http_kwargs = params.client_call_context.state.get('http_kwargs', {})
-  headers = http_kwargs.get('headers', {})
+  headers = params.client_call_context.service_parameters or {}
   a2a_extensions = headers.get(HTTP_EXTENSION_HEADER, '').split(',')
   a2a_extensions = [ext for ext in a2a_extensions if ext]
   if _NEW_A2A_ADK_INTEGRATION_EXTENSION not in a2a_extensions:
     a2a_extensions.append(_NEW_A2A_ADK_INTEGRATION_EXTENSION)
   headers[HTTP_EXTENSION_HEADER] = ','.join(a2a_extensions)
-  http_kwargs['headers'] = headers
-  params.client_call_context.state['http_kwargs'] = http_kwargs
+  params.client_call_context.service_parameters = headers
   return a2a_request, params
 
 

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

@@ -20,7 +20,7 @@
 from typing import Union
 
 from a2a.client import ClientEvent as A2AClientEvent
-from a2a.client.middleware import ClientCallContext
+from a2a.client import ClientCallContext
 from a2a.types import Message as A2AMessage
 
 from ...agents.invocation_context import InvocationContext

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

@@ -24,18 +24,18 @@
 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
+from google.protobuf.json_format import MessageToDict
+from google.protobuf.timestamp_pb2 import Timestamp
 
 from ...agents.invocation_context import InvocationContext
 from ...events.event import Event
@@ -105,6 +105,83 @@ def _serialize_metadata_value(value: Any) -> str:
   return str(value)
 
 
+def _get_part_metadata_value(part: A2APart, key: str) -> Any:
+  """Returns a metadata value from either proto Struct or dict-like metadata."""
+  metadata = getattr(part, "metadata", None)
+  if not metadata:
+    return None
+  try:
+    return metadata.get(key)
+  except AttributeError:
+    try:
+      return metadata[key]
+    except Exception:
+      return None
+
+
+def _get_part_data_dict(part: A2APart) -> Dict[str, Any]:
+  """Returns a part's data payload as a plain dict when possible."""
+  data = getattr(part, "data", None)
+  if data is None:
+    return {}
+  if isinstance(data, dict):
+    return data
+  get_method = getattr(data, "get", None)
+  if callable(get_method):
+    try:
+      return {
+          "id": get_method("id"),
+          "name": get_method("name"),
+      }
+    except Exception:
+      pass
+  try:
+    return MessageToDict(data)
+  except Exception:
+    return {}
+
+
+def _coerce_a2a_message(message: Message | Any) -> Message:
+  """Returns a proto Message, tolerating older mock/dict-style inputs in tests."""
+  if (
+      isinstance(message, Message)
+      and type(message).__module__ != "unittest.mock"
+  ):
+    return message
+
+  coerced_message = Message()
+  for field_name in ("message_id", "task_id", "context_id"):
+    field_value = getattr(message, field_name, None)
+    if field_value:
+      setattr(coerced_message, field_name, field_value)
+
+  role = getattr(message, "role", None)
+  if role is not None:
+    coerced_message.role = role
+  else:
+    coerced_message.role = Role.ROLE_AGENT
+
+  parts = getattr(message, "parts", None)
+  if parts:
+    for part in parts:
+      if isinstance(part, A2APart):
+        coerced_message.parts.append(part)
+
+  metadata = getattr(message, "metadata", None)
+  if metadata:
+    coerced_message.metadata.update(metadata)
+
+  return coerced_message
+
+
+def _create_timestamp() -> Timestamp:
+  """Creates a protobuf timestamp from the current platform time."""
+  now = platform_time.get_time()
+  seconds = int(now)
+  nanos = int((now - seconds) * 1_000_000_000)
+  return Timestamp(seconds=seconds, nanos=nanos)
+
+
 def _get_context_metadata(
     event: Event, invocation_context: InvocationContext
 ) -> Dict[str, str]:
@@ -184,19 +261,30 @@ def _process_long_running_tool(a2a_part: A2APart, event: Event) -> None:
     a2a_part: The A2A part to potentially mark as long-running.
     event: The ADK event containing long-running tool information.
   """
-  if (
-      isinstance(a2a_part.root, DataPart)
-      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)
-      )
-      == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
-      and a2a_part.root.data.get("id") in event.long_running_tool_ids
-  ):
-    a2a_part.root.metadata[
-        _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY)
-    ] = True
+  if not event.long_running_tool_ids or not getattr(a2a_part, "metadata", None):
+    return
+  has_data = getattr(a2a_part, "HasField", None)
+  if callable(has_data):
+    try:
+      if not a2a_part.HasField("data"):
+        return
+    except Exception:
+      pass
+
+  type_key = _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
+  part_type = (
+      _get_part_metadata_value(a2a_part, type_key)
+      or _get_part_metadata_value(a2a_part, A2A_DATA_PART_METADATA_TYPE_KEY)
+      or _get_part_metadata_value(a2a_part, "adk_type")
+  )
+  if part_type != A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL:
+    return
+
+  data_dict = _get_part_data_dict(a2a_part)
+  if data_dict.get("id") in event.long_running_tool_ids:
+    a2a_part.metadata.update({
+        _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY): True
+    })
 
 
 def convert_a2a_task_to_event(
@@ -229,7 +317,7 @@ 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=a2a_task.artifacts[-1].parts
       )
     elif (
         a2a_task.status
@@ -321,15 +409,10 @@ def convert_a2a_message_to_event(
           continue
 
         # Check for long-running tools
-        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
-        ):
+        if _get_part_metadata_value(
+            a2a_part,
+            _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY),
+        ) is True:
           for part in parts:
             if part.function_call:
               long_running_tool_ids.add(part.function_call.id)
@@ -372,7 +455,7 @@ def convert_a2a_message_to_event(
 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.
@@ -446,22 +529,19 @@ def _create_error_status_event(
       context_id=context_id,
       metadata=event_metadata,
       status=TaskStatus(
-          state=TaskState.failed,
+          state=TaskState.TASK_STATE_FAILED,
           message=Message(
               message_id=platform_uuid.new_uuid(),
-              role=Role.agent,
-              parts=[TextPart(text=error_message)],
+              role=Role.ROLE_AGENT,
+              parts=[A2APart(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,
+          timestamp=_create_timestamp(),
+      )
   )
 
 
@@ -484,48 +564,45 @@ def _create_status_update_event(
   Returns:
     A TaskStatusUpdateEvent with RUNNING state.
   """
+  proto_message = _coerce_a2a_message(message)
+
   status = TaskStatus(
-      state=TaskState.working,
-      message=message,
-      timestamp=datetime.fromtimestamp(
-          platform_time.get_time(), tz=timezone.utc
-      ).isoformat(),
+      state=TaskState.TASK_STATE_WORKING,
+      message=proto_message,
+      timestamp=_create_timestamp(),
   )
 
-  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
-      for part in message.parts
-      if part.root.metadata
-  ):
-    status.state = TaskState.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
-      for part in message.parts
-      if part.root.metadata
-  ):
-    status.state = TaskState.input_required
+  def _is_long_running(part: A2APart) -> bool:
+    val = _get_part_metadata_value(
+        part,
+        _get_adk_metadata_key(A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY),
+    )
+    return str(val).lower() == "true" or val is True
+
+  for part in message.parts:
+    part_type = (
+        _get_part_metadata_value(
+            part, _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
+        )
+        or _get_part_metadata_value(part, A2A_DATA_PART_METADATA_TYPE_KEY)
+        or _get_part_metadata_value(part, "adk_type")
+    )
+    if (
+        part_type == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
+        and _is_long_running(part)
+    ):
+      data_dict = _get_part_data_dict(part)
+      if data_dict.get("name") == REQUEST_EUC_FUNCTION_CALL_NAME:
+        status.state = TaskState.TASK_STATE_AUTH_REQUIRED
+        break
+      status.state = TaskState.TASK_STATE_INPUT_REQUIRED
+      break
 
   return TaskStatusUpdateEvent(
       task_id=task_id,
       context_id=context_id,
       status=status,
       metadata=_get_context_metadata(event, invocation_context),
-      final=False,
   )