chore: Fallback to import package a2a_sdk when a2a is not available

contributing/samples/a2a_root/agent.py

@@ -12,7 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from a2a.utils.constants import AGENT_CARD_WELL_KNOWN_PATH
+
+from google.adk.agents.remote_a2a_agent import AGENT_CARD_WELL_KNOWN_PATH
 from google.adk.agents.remote_a2a_agent import RemoteA2aAgent
 
 root_agent = RemoteA2aAgent(

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

@@ -17,22 +17,49 @@
 from datetime import datetime
 from datetime import timezone
 import logging
+import sys
 from typing import Any
 from typing import Dict
 from typing import List
 from typing import Optional
 import uuid
 
-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
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      "A2A requires Python 3.10 or above. Please upgrade your Python version. "
+      f"Current version: {sys.version_info.major}.{sys.version_info.minor}"
+  )
+
+# Import a2a packages with fallback to a2a_sdk
+try:
+  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
+except ImportError:
+  try:
+    from a2a_sdk.server.events import Event as A2AEvent
+    from a2a_sdk.types import DataPart
+    from a2a_sdk.types import Message
+    from a2a_sdk.types import Part as A2APart
+    from a2a_sdk.types import Role
+    from a2a_sdk.types import Task
+    from a2a_sdk.types import TaskState
+    from a2a_sdk.types import TaskStatus
+    from a2a_sdk.types import TaskStatusUpdateEvent
+    from a2a_sdk.types import TextPart
+  except ImportError:
+    raise ImportError(
+        "Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a"
+        " dependency."
+    )
 from google.genai import types as genai_types
 
 from ...agents.invocation_context import InvocationContext

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

@@ -21,22 +21,29 @@
 import base64
 import json
 import logging
+import sys
 from typing import Optional
 
 from .utils import _get_adk_metadata_key
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      'A2A requires Python 3.10 or above. Please upgrade your Python version. '
+      f'Current version: {sys.version_info.major}.{sys.version_info.minor}'
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a import types as a2a_types
-except ImportError as e:
-  import sys
-
-  if sys.version_info < (3, 10):
+except ImportError:
+  try:
+    from a2a_sdk import types as a2a_types
+  except ImportError:
     raise ImportError(
-        'A2A requires Python 3.10 or above. Please upgrade your Python version.'
-    ) from e
-  else:
-    raise e
-
+        'Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a'
+        ' dependency.'
+    )
 from google.genai import types as genai_types
 
 from ...utils.feature_decorator import experimental

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

@@ -17,16 +17,24 @@
 import sys
 from typing import Any
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      'A2A requires Python 3.10 or above. Please upgrade your Python version. '
+      f'Current version: {sys.version_info.major}.{sys.version_info.minor}'
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a.server.agent_execution import RequestContext
-except ImportError as e:
-  if sys.version_info < (3, 10):
+except ImportError:
+  try:
+    from a2a_sdk.server.agent_execution import RequestContext
+  except ImportError:
     raise ImportError(
-        'A2A requires Python 3.10 or above. Please upgrade your Python version.'
-    ) from e
-  else:
-    raise e
-
+        'Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a'
+        ' dependency.'
+    )
 from google.genai import types as genai_types
 
 from ...runners import RunConfig

src/google/adk/a2a/executor/a2a_agent_executor.py

@@ -18,12 +18,21 @@
 from datetime import timezone
 import inspect
 import logging
+import sys
 from typing import Any
 from typing import Awaitable
 from typing import Callable
 from typing import Optional
 import uuid
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      'A2A requires Python 3.10 or above. Please upgrade your Python version. '
+      f'Current version: {sys.version_info.major}.{sys.version_info.minor}'
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a.server.agent_execution import AgentExecutor
   from a2a.server.agent_execution.context import RequestContext
@@ -36,16 +45,24 @@
   from a2a.types import TaskStatus
   from a2a.types import TaskStatusUpdateEvent
   from a2a.types import TextPart
-
-except ImportError as e:
-  import sys
-
-  if sys.version_info < (3, 10):
+except ImportError:
+  try:
+    from a2a_sdk.server.agent_execution import AgentExecutor
+    from a2a_sdk.server.agent_execution.context import RequestContext
+    from a2a_sdk.server.events.event_queue import EventQueue
+    from a2a_sdk.types import Artifact
+    from a2a_sdk.types import Message
+    from a2a_sdk.types import Role
+    from a2a_sdk.types import TaskArtifactUpdateEvent
+    from a2a_sdk.types import TaskState
+    from a2a_sdk.types import TaskStatus
+    from a2a_sdk.types import TaskStatusUpdateEvent
+    from a2a_sdk.types import TextPart
+  except ImportError:
     raise ImportError(
-        'A2A requires Python 3.10 or above. Please upgrade your Python version.'
-    ) from e
-  else:
-    raise e
+        'Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a'
+        ' dependency.'
+    )
 from google.adk.runners import Runner
 from pydantic import BaseModel
 from typing_extensions import override

src/google/adk/a2a/executor/task_result_aggregator.py

@@ -14,10 +14,32 @@
 
 from __future__ import annotations
 
-from a2a.server.events import Event
-from a2a.types import Message
-from a2a.types import TaskState
-from a2a.types import TaskStatusUpdateEvent
+import sys
+
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      'A2A requires Python 3.10 or above. Please upgrade your Python version. '
+      f'Current version: {sys.version_info.major}.{sys.version_info.minor}'
+  )
+
+# Import a2a packages with fallback to a2a_sdk
+try:
+  from a2a.server.events import Event
+  from a2a.types import Message
+  from a2a.types import TaskState
+  from a2a.types import TaskStatusUpdateEvent
+except ImportError:
+  try:
+    from a2a_sdk.server.events import Event
+    from a2a_sdk.types import Message
+    from a2a_sdk.types import TaskState
+    from a2a_sdk.types import TaskStatusUpdateEvent
+  except ImportError:
+    raise ImportError(
+        'Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a'
+        ' dependency.'
+    )
 
 from ...utils.feature_decorator import experimental
 

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

@@ -20,20 +20,32 @@
 from typing import List
 from typing import Optional
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      'A2A requires Python 3.10 or above. Please upgrade your Python version. '
+      f'Current version: {sys.version_info.major}.{sys.version_info.minor}'
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a.types import AgentCapabilities
   from a2a.types import AgentCard
   from a2a.types import AgentProvider
   from a2a.types import AgentSkill
   from a2a.types import SecurityScheme
-except ImportError as e:
-  if sys.version_info < (3, 10):
+except ImportError:
+  try:
+    from a2a_sdk.types import AgentCapabilities
+    from a2a_sdk.types import AgentCard
+    from a2a_sdk.types import AgentProvider
+    from a2a_sdk.types import AgentSkill
+    from a2a_sdk.types import SecurityScheme
+  except ImportError:
     raise ImportError(
-        'A2A requires Python 3.10 or above. Please upgrade your Python version.'
-    ) from e
-  else:
-    raise e
-
+        'Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a'
+        ' dependency.'
+    )
 
 from ...agents.base_agent import BaseAgent
 from ...agents.llm_agent import LlmAgent

src/google/adk/a2a/utils/agent_to_a2a.py

@@ -17,18 +17,28 @@
 import logging
 import sys
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      "A2A requires Python 3.10 or above. Please upgrade your Python version. "
+      f"Current version: {sys.version_info.major}.{sys.version_info.minor}"
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a.server.apps import A2AStarletteApplication
   from a2a.server.request_handlers import DefaultRequestHandler
   from a2a.server.tasks import InMemoryTaskStore
-except ImportError as e:
-  if sys.version_info < (3, 10):
+except ImportError:
+  try:
+    from a2a_sdk.server.apps import A2AStarletteApplication
+    from a2a_sdk.server.request_handlers import DefaultRequestHandler
+    from a2a_sdk.server.tasks import InMemoryTaskStore
+  except ImportError:
     raise ImportError(
-        "A2A requires Python 3.10 or above. Please upgrade your Python version."
-    ) from e
-  else:
-    raise e
-
+        "Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a"
+        " dependency."
+    )
 from starlette.applications import Starlette
 
 from ...agents.base_agent import BaseAgent

src/google/adk/agents/remote_a2a_agent.py

@@ -17,13 +17,22 @@
 import json
 import logging
 from pathlib import Path
+import sys
 from typing import Any
 from typing import AsyncGenerator
 from typing import Optional
 from typing import Union
 from urllib.parse import urlparse
 import uuid
 
+# Check Python version first
+if sys.version_info < (3, 10):
+  raise ImportError(
+      "A2A requires Python 3.10 or above. Please upgrade your Python version. "
+      f"Current version: {sys.version_info.major}.{sys.version_info.minor}"
+  )
+
+# Import a2a packages with fallback to a2a_sdk
 try:
   from a2a.client import A2AClient
   from a2a.client.card_resolver import A2ACardResolver
@@ -35,22 +44,25 @@
   from a2a.types import SendMessageRequest
   from a2a.types import SendMessageSuccessResponse
   from a2a.types import Task as A2ATask
-except ImportError as e:
-  import sys
-
-  if sys.version_info < (3, 10):
-    raise ImportError(
-        "A2A requires Python 3.10 or above. Please upgrade your Python version."
-    ) from e
-  else:
-    raise e
-
-try:
   from a2a.utils.constants import AGENT_CARD_WELL_KNOWN_PATH
 except ImportError:
-  # Fallback for older versions of a2a-sdk.
-  AGENT_CARD_WELL_KNOWN_PATH = "/.well-known/agent.json"
-
+  try:
+    from a2a_sdk.client import A2AClient
+    from a2a_sdk.client.card_resolver import A2ACardResolver
+    from a2a_sdk.types import AgentCard
+    from a2a_sdk.types import Message as A2AMessage
+    from a2a_sdk.types import MessageSendParams as A2AMessageSendParams
+    from a2a_sdk.types import Part as A2APart
+    from a2a_sdk.types import Role
+    from a2a_sdk.types import SendMessageRequest
+    from a2a_sdk.types import SendMessageSuccessResponse
+    from a2a_sdk.types import Task as A2ATask
+    from a2a_sdk.utils.constants import AGENT_CARD_WELL_KNOWN_PATH
+  except ImportError:
+    raise ImportError(
+        "Could not import a2a or a2a_sdk packages. Please install a2a-sdk as a"
+        " dependency."
+    )
 from google.genai import types as genai_types
 import httpx