fix: update a2a-sdk compatibility

update Python packages to depend on a2a-sdk >=1.0.2 and refresh uv.lock to 1.0.3
move KAgent's internal A2A model usage to the SDK v0.3 compatibility namespace
add compatibility shims for removed a2a-sdk 0.3 server app helpers and google-adk imports while wiring 1.x request handlers/cards
update remote A2A tool middleware handling for the a2a-sdk 1.x client interceptor API

Signed-off-by: Jaison Paul <jaison.paul@capitalone.com>

Author: Jaison Paul

python/packages/kagent-adk/pyproject.toml

@@ -29,7 +29,7 @@ dependencies = [
   "pydantic>=2.5.0",
   "typing-extensions>=4.8.0",
   "jsonref>=1.1.0",
-  "a2a-sdk>=0.3.23",
+  "a2a-sdk>=1.0.2,<2.0",
   # Security: pin minimum versions for CVE fixes in transitive dependencies
   "urllib3>=2.6.3",  # CVE-2025-66418, CVE-2025-66471, CVE-2026-21441: unbounded decompression DoS
   "filelock>=3.20.3",  # CVE-2025-68146, CVE-2026-22701: TOCTOU symlink race condition

python/packages/kagent-adk/src/kagent/adk/_a2a.py

@@ -5,10 +5,10 @@
 from typing import Any, Callable, List, Optional
 
 import httpx
-from a2a.server.apps import A2AFastAPIApplication
+from a2a.compat.v0_3.conversions import to_core_agent_card
+from a2a.compat.v0_3.types import AgentCard
 from a2a.server.request_handlers import DefaultRequestHandler
 from a2a.server.tasks import InMemoryTaskStore
-from a2a.types import AgentCard
 from agentsts.adk import ADKSTSIntegration, ADKTokenPropagationPlugin
 from fastapi import FastAPI, Request
 from fastapi.responses import PlainTextResponse
@@ -25,6 +25,7 @@
     KAgentTaskStore,
     get_a2a_max_content_length,
 )
+from kagent.core.a2a._server_apps import A2AFastAPIApplication
 
 from ._agent_executor import A2aAgentExecutor, A2aAgentExecutorConfig
 from ._lifespan import LifespanManager
@@ -147,6 +148,7 @@ def create_runner() -> Runner:
         request_handler = DefaultRequestHandler(
             agent_executor=agent_executor,
             task_store=task_store,
+            agent_card=to_core_agent_card(self.agent_card),
             request_context_builder=request_context_builder,
         )
 

python/packages/kagent-adk/src/kagent/adk/_agent_executor.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+# ruff: noqa: E402
 import asyncio
 import inspect
 import logging
@@ -8,9 +9,7 @@
 from datetime import datetime, timezone
 from typing import Any, Awaitable, Callable, Optional
 
-from a2a.server.agent_execution.context import RequestContext
-from a2a.server.events.event_queue import EventQueue
-from a2a.types import (
+from a2a.compat.v0_3.types import (
     Artifact,
     Message,
     Part,
@@ -21,12 +20,23 @@
     TaskStatusUpdateEvent,
     TextPart,
 )
+from a2a.server.agent_execution.context import RequestContext
+from a2a.server.events.event_queue import EventQueue
+from kagent.core.a2a._compat import install_v03_type_aliases, restore_a2a_type_aliases
+
+# google-adk imports v0.3 A2A types from a2a.types during module import.
+# Keep these imports below the temporary alias install, then restore the 1.x
+# namespace so a2a-sdk internals continue to see their native protobuf types.
+_a2a_type_originals = install_v03_type_aliases(overwrite=True)
+
 from google.adk.a2a.executor.a2a_agent_executor import (
     A2aAgentExecutor as UpstreamA2aAgentExecutor,
 )
 from google.adk.a2a.executor.a2a_agent_executor import (
     A2aAgentExecutorConfig as UpstreamA2aAgentExecutorConfig,
 )
+
+restore_a2a_type_aliases(_a2a_type_originals)
 from google.adk.events import Event, EventActions
 from google.adk.flows.llm_flows.functions import REQUEST_CONFIRMATION_FUNCTION_CALL_NAME
 from google.adk.runners import Runner

python/packages/kagent-adk/src/kagent/adk/_remote_a2a_tool.py

@@ -11,33 +11,39 @@
 This is a BaseToolset wrapper around KAgentRemoteA2ATool for runner cleanup purposes.
 """
 
+# ruff: noqa: E402
+
 import logging
 import uuid
 from typing import Any, Callable, Optional, Protocol, runtime_checkable
 from urllib.parse import urlparse
 
 import httpx
+from kagent.core.a2a._compat import install_v03_type_aliases
+
+install_v03_type_aliases()
+
 from a2a.client import Client as A2AClient
 from a2a.client.card_resolver import A2ACardResolver
 from a2a.client.client import ClientConfig as A2AClientConfig
 from a2a.client.client_factory import ClientFactory as A2AClientFactory
 from a2a.client.errors import A2AClientHTTPError
 from a2a.client.middleware import ClientCallContext, ClientCallInterceptor
-from a2a.types import (
+from a2a.compat.v0_3.types import (
     AgentCard,
     DataPart,
     Role,
     Task,
     TaskState,
     TextPart,
 )
-from a2a.types import (
+from a2a.compat.v0_3.types import (
     Message as A2AMessage,
 )
-from a2a.types import (
+from a2a.compat.v0_3.types import (
     Part as A2APart,
 )
-from a2a.types import (
+from a2a.compat.v0_3.types import (
     TransportProtocol as A2ATransport,
 )
 from google.adk.agents.readonly_context import ReadonlyContext
@@ -70,18 +76,23 @@ class _SubagentInterceptor(ClientCallInterceptor):
     headers stored in the call context state under ``_EXTRA_HEADERS_CONTEXT_KEY``.
     """
 
-    async def intercept(self, method_name, request_payload, http_kwargs, agent_card, context):
-        headers = dict(http_kwargs.get("headers", {}))
+    async def before(self, args) -> None:
+        context = args.context
+        if context is None:
+            return
+        headers = dict(context.service_parameters or {})
         headers[_SOURCE_HEADER] = _SOURCE_SUBAGENT
 
-        if context:
-            if _USER_ID_CONTEXT_KEY in context.state:
-                headers["x-user-id"] = context.state[_USER_ID_CONTEXT_KEY]
-            extra = context.state.get(_EXTRA_HEADERS_CONTEXT_KEY)
-            if extra:
-                headers.update(extra)
-        http_kwargs["headers"] = headers
-        return request_payload, http_kwargs
+        if _USER_ID_CONTEXT_KEY in context.state:
+            headers["x-user-id"] = context.state[_USER_ID_CONTEXT_KEY]
+        extra = context.state.get(_EXTRA_HEADERS_CONTEXT_KEY)
+        if extra:
+            headers.update(extra)
+
+        context.service_parameters = headers
+
+    async def after(self, args) -> None:
+        return None
 
 
 def _extract_text_from_task(task: Task) -> str:

python/packages/kagent-adk/src/kagent/adk/cli.py

@@ -7,7 +7,7 @@
 
 import typer
 import uvicorn
-from a2a.types import AgentCard
+from a2a.compat.v0_3.types import AgentCard
 from agentsts.adk import ADKSTSIntegration, ADKTokenPropagationPlugin
 from google.adk.agents import BaseAgent
 from google.adk.cli.utils.agent_loader import AgentLoader

python/packages/kagent-adk/src/kagent/adk/converters/event_converter.py

@@ -5,9 +5,9 @@
 from datetime import datetime, timezone
 from typing import Any, Dict, List, Optional
 
+from a2a.compat.v0_3.types import DataPart, Message, Role, Task, TaskState, TaskStatus, TaskStatusUpdateEvent, TextPart
+from a2a.compat.v0_3.types import Part as A2APart
 from a2a.server.events import Event as A2AEvent
-from a2a.types import DataPart, Message, Role, Task, TaskState, TaskStatus, TaskStatusUpdateEvent, TextPart
-from a2a.types import Part as A2APart
 from google.adk.agents.invocation_context import InvocationContext
 from google.adk.events.event import Event
 from google.adk.flows.llm_flows.functions import REQUEST_EUC_FUNCTION_CALL_NAME

python/packages/kagent-adk/src/kagent/adk/converters/part_converter.py

@@ -23,7 +23,7 @@
 import logging
 from typing import Optional
 
-from a2a import types as a2a_types
+from a2a.compat.v0_3 import types as a2a_types
 from google.genai import types as genai_types
 from kagent.core.a2a import (
     A2A_DATA_PART_METADATA_TYPE_CODE_EXECUTION_RESULT,

python/packages/kagent-adk/src/kagent/adk/types.py

@@ -1,8 +1,17 @@
+# ruff: noqa: E402
+
 import logging
 from typing import Any, Callable, Literal, Optional, Union
 
 import httpx
 from agentsts.adk import ADKTokenPropagationPlugin
+from kagent.core.a2a._compat import install_v03_type_aliases
+
+# google-adk's RemoteA2aAgent still imports the removed v0.3 model names from
+# a2a.types. This import-order guard keeps that transitive import working with
+# a2a-sdk 1.x; keep the google.adk imports below this call.
+install_v03_type_aliases(overwrite=True)
+
 from google.adk.agents import Agent
 from google.adk.agents.callback_context import CallbackContext
 from google.adk.agents.llm_agent import ToolUnion

python/packages/kagent-adk/tests/unittests/converters/test_event_converter.py

@@ -1,7 +1,7 @@
 from unittest.mock import Mock
 
 import pytest
-from a2a.types import TaskState, TaskStatusUpdateEvent
+from a2a.compat.v0_3.types import TaskState, TaskStatusUpdateEvent
 from google.genai import types as genai_types
 from kagent.core.a2a import get_kagent_metadata_key
 

python/packages/kagent-adk/tests/unittests/models/test_sap_ai_core.py

@@ -17,7 +17,6 @@
     _parse_orchestration_chunk,
 )
 
-
 # ---------------------------------------------------------------------------
 # Helpers
 # ---------------------------------------------------------------------------