diff --git a/workspace/a2a_executor.py b/workspace/a2a_executor.py
index 39ca159e..0c160645 100644
--- a/workspace/a2a_executor.py
+++ b/workspace/a2a_executor.py
@@ -39,8 +39,9 @@ import uuid
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
 from a2a.server.tasks import TaskUpdater
-from a2a.types import Part, TextPart
-from a2a.utils import new_agent_text_message
+from a2a.types import Part
+# KI-009: a2a-sdk v1 renames a2a.utils → a2a.helpers; TextPart removed (Part takes text= directly)
+from a2a.helpers import new_agent_text_message
 from shared_runtime import (
     extract_history as _extract_history,
     extract_message_text,
@@ -334,7 +335,7 @@ class LangGraphA2AExecutor(AgentExecutor):
                                 texts = _extract_chunk_text(chunk.content)
                                 for text in texts:
                                     await updater.add_artifact(
-                                        parts=[Part(root=TextPart(text=text))],
+                                        parts=[Part(text=text)],  # v1: TextPart removed, Part takes text= directly
                                         artifact_id=artifact_id,
                                         append=has_streamed,  # False=first, True=append
                                         last_chunk=False,
@@ -446,7 +447,7 @@ class LangGraphA2AExecutor(AgentExecutor):
         from a2a.types import TaskStatus, TaskState, TaskStatusUpdateEvent
         await event_queue.enqueue_event(
             TaskStatusUpdateEvent(
-                status=TaskStatus(state=TaskState.canceled),
+                status=TaskStatus(state=TaskState.TASK_STATE_CANCELED),  # v1: TaskState uses SCREAMING_SNAKE_CASE
                 final=True,
             )
         )
diff --git a/workspace/adapters/google-adk/adapter.py b/workspace/adapters/google-adk/adapter.py
index 5b21e4f1..8b3fe9db 100644
--- a/workspace/adapters/google-adk/adapter.py
+++ b/workspace/adapters/google-adk/adapter.py
@@ -36,7 +36,7 @@ from typing import TYPE_CHECKING, Any
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
-from a2a.utils import new_agent_text_message
+from a2a.helpers import new_agent_text_message
 
 from adapter_base import AdapterConfig, BaseAdapter
 
@@ -243,7 +243,7 @@ class GoogleADKA2AExecutor(AgentExecutor):
 
         await event_queue.enqueue_event(
             TaskStatusUpdateEvent(
-                status=TaskStatus(state=TaskState.canceled),
+                status=TaskStatus(state=TaskState.TASK_STATE_CANCELED),
                 final=True,
             )
         )
diff --git a/workspace/adapters/google-adk/test_adapter.py b/workspace/adapters/google-adk/test_adapter.py
index 7a185c1a..770d088c 100644
--- a/workspace/adapters/google-adk/test_adapter.py
+++ b/workspace/adapters/google-adk/test_adapter.py
@@ -69,21 +69,18 @@ def _make_a2a_stubs() -> None:
     tasks_mod = ModuleType("a2a.server.tasks")
     types_mod = ModuleType("a2a.types")
 
-    class TextPart:
-        def __init__(self, text=""):
+    class Part:
+        # v1: Part takes text= directly; root= retained for compat during transition
+        def __init__(self, text=None, root=None, **kwargs):
             self.text = text
 
-    class Part:
-        def __init__(self, root=None):
-            self.root = root
-
-    types_mod.TextPart = TextPart
     types_mod.Part = Part
 
-    utils_mod = ModuleType("a2a.utils")
+    # a2a.helpers (v1: moved from a2a.utils)
+    helpers_mod = ModuleType("a2a.helpers")
     # Passthrough so tests can assert on the plain text string, matching the
     # hermes_executor test convention from conftest.py.
-    utils_mod.new_agent_text_message = lambda text, **kwargs: text
+    helpers_mod.new_agent_text_message = lambda text, **kwargs: text
 
     a2a_mod = ModuleType("a2a")
     a2a_server_mod = ModuleType("a2a.server")
@@ -94,7 +91,7 @@ def _make_a2a_stubs() -> None:
     sys.modules["a2a.server.events"] = events_mod
     sys.modules["a2a.server.tasks"] = tasks_mod
     sys.modules["a2a.types"] = types_mod
-    sys.modules["a2a.utils"] = utils_mod
+    sys.modules["a2a.helpers"] = helpers_mod
 
 
 def _make_google_adk_stubs() -> None:
diff --git a/workspace/claude_sdk_executor.py b/workspace/claude_sdk_executor.py
index f702eef5..e299af6f 100644
--- a/workspace/claude_sdk_executor.py
+++ b/workspace/claude_sdk_executor.py
@@ -39,7 +39,7 @@ import claude_agent_sdk as sdk
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
-from a2a.utils import new_agent_text_message
+from a2a.helpers import new_agent_text_message
 
 from executor_helpers import (
     CONFIG_MOUNT,
diff --git a/workspace/cli_executor.py b/workspace/cli_executor.py
index 2f2802ec..5be84d9f 100644
--- a/workspace/cli_executor.py
+++ b/workspace/cli_executor.py
@@ -34,7 +34,8 @@ from pathlib import Path
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
-from a2a.utils import new_agent_text_message
+# KI-009: a2a-sdk v1 renames a2a.utils → a2a.helpers
+from a2a.helpers import new_agent_text_message
 
 from config import RuntimeConfig
 from executor_helpers import (
diff --git a/workspace/hermes_executor.py b/workspace/hermes_executor.py
index ceeeddba..e9453560 100644
--- a/workspace/hermes_executor.py
+++ b/workspace/hermes_executor.py
@@ -113,7 +113,7 @@ from typing import TYPE_CHECKING, Any
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
-from a2a.utils import new_agent_text_message
+from a2a.helpers import new_agent_text_message
 
 if TYPE_CHECKING:
     from heartbeat import HeartbeatLoop
@@ -539,7 +539,7 @@ class HermesA2AExecutor(AgentExecutor):
 
         await event_queue.enqueue_event(
             TaskStatusUpdateEvent(
-                status=TaskStatus(state=TaskState.canceled),
+                status=TaskStatus(state=TaskState.TASK_STATE_CANCELED),
                 final=True,
             )
         )
diff --git a/workspace/main.py b/workspace/main.py
index c95feba6..1cdd64aa 100644
--- a/workspace/main.py
+++ b/workspace/main.py
@@ -10,10 +10,12 @@ import socket
 
 import httpx
 import uvicorn
-from a2a.server.apps import A2AStarletteApplication
+# KI-009 a2a-sdk v1 migration: A2AStarletteApplication removed; use Starlette route factory
+from a2a.server.routes import create_agent_card_routes, create_jsonrpc_routes
 from a2a.server.request_handlers import DefaultRequestHandler
 from a2a.server.tasks import InMemoryTaskStore
-from a2a.types import AgentCard, AgentCapabilities, AgentSkill
+from a2a.types import AgentCard, AgentCapabilities, AgentSkill, AgentInterface
+from starlette.applications import Starlette
 
 from adapters import get_adapter, AdapterConfig
 from agents_md import generate_agents_md
@@ -164,15 +166,20 @@ async def main():  # pragma: no cover
     machine_ip = os.environ.get("HOSTNAME", get_machine_ip())
     workspace_url = f"http://{machine_ip}:{port}"
 
+    # v1: AgentCard.url removed; put url+protocol in supported_protocols instead.
+    # v1: AgentCapabilities.inputModes/outputModes removed; move to AgentCard.default_*.
+    # v1: pushNotifications → push_notifications (Pydantic field name)
     agent_card = AgentCard(
         name=config.name,
         description=config.description or config.name,
         version=config.version,
-        url=workspace_url,
+        supported_protocols=[
+            AgentInterface(protocol_binding="https://a2a.g/v1", url=workspace_url)
+        ],
         capabilities=AgentCapabilities(
             streaming=config.a2a.streaming,
-            pushNotifications=config.a2a.push_notifications,
-            stateTransitionHistory=True,
+            push_notifications=config.a2a.push_notifications,
+            state_transition_history=True,
         ),
         skills=[
             AgentSkill(
@@ -184,8 +191,8 @@ async def main():  # pragma: no cover
             )
             for skill in loaded_skills
         ],
-        defaultInputModes=["text/plain", "application/json"],
-        defaultOutputModes=["text/plain", "application/json"],
+        default_input_modes=["text/plain", "application/json"],
+        default_output_modes=["text/plain", "application/json"],
     )
 
     # 7. Wrap in A2A.
@@ -204,10 +211,11 @@ async def main():  # pragma: no cover
         task_store=InMemoryTaskStore(),
     )
 
-    app = A2AStarletteApplication(
-        agent_card=agent_card,
-        http_handler=handler,
-    )
+    # v1: replace A2AStarletteApplication with Starlette route factory
+    routes = []
+    routes.extend(create_agent_card_routes(agent_card))
+    routes.extend(create_jsonrpc_routes(request_handler=handler))
+    app = Starlette(routes=routes)
 
     # 8. Register with platform
     agent_card_dict = {
@@ -316,7 +324,8 @@ async def main():  # pragma: no cover
     print(f"Workspace {workspace_id} starting on port {port}")
     # Wrap the ASGI app with W3C TraceContext extraction middleware so incoming
     # A2A HTTP requests propagate their trace context into _incoming_trace_context.
-    starlette_app = app.build()
+    # v1: Starlette app is constructed directly; no build() step needed
+    starlette_app = app
 
     # Add /transcript route — exposes the most-recent agent session log
     # (claude-code reads ~/.claude/projects/<cwd>/<session>.jsonl). Other
diff --git a/workspace/requirements.txt b/workspace/requirements.txt
index 24b11e35..b58699de 100644
--- a/workspace/requirements.txt
+++ b/workspace/requirements.txt
@@ -3,7 +3,10 @@
 # and installed at container startup via entrypoint.sh
 
 # A2A protocol
-a2a-sdk[http-server]==0.3.25
+# KI-009 a2a-sdk v1 migration (2026-04-24): bumped from ==0.3.25.
+# v1.0 removes A2AStarletteApplication → Starlette route factory pattern.
+# Rollback: pin ==0.3.25 and revert main.py + executor changes.
+a2a-sdk[http-server]>=1.0.0,<2.0
 
 # HTTP / server
 httpx>=0.27.0
diff --git a/workspace/tests/conftest.py b/workspace/tests/conftest.py
index 1465d12c..4c1c5f04 100644
--- a/workspace/tests/conftest.py
+++ b/workspace/tests/conftest.py
@@ -65,25 +65,19 @@ def _make_a2a_mocks():
 
     tasks_mod.TaskUpdater = TaskUpdater
 
-    # a2a.types needs Part and TextPart stubs for artifact construction
+    # a2a.types needs Part stub for artifact construction (v1: Part takes text= directly, no TextPart)
     types_mod = ModuleType("a2a.types")
 
-    class TextPart:
-        """Stub for A2A TextPart."""
-        def __init__(self, text=""):
+    class Part:
+        """Stub for A2A Part (v1: takes text= kwarg directly)."""
+        def __init__(self, text=None, root=None, **kwargs):
             self.text = text
 
-    class Part:
-        """Stub for A2A Part (wraps TextPart / FilePart / DataPart)."""
-        def __init__(self, root=None):
-            self.root = root
-
-    types_mod.TextPart = TextPart
     types_mod.Part = Part
 
-    # a2a.utils needs new_agent_text_message as a passthrough (accepts kwargs)
-    utils_mod = ModuleType("a2a.utils")
-    utils_mod.new_agent_text_message = lambda text, **kwargs: text
+    # a2a.helpers (v1: moved from a2a.utils)
+    helpers_mod = ModuleType("a2a.helpers")
+    helpers_mod.new_agent_text_message = lambda text, **kwargs: text
 
     # Register all module paths
     a2a_mod = ModuleType("a2a")
@@ -95,7 +89,7 @@ def _make_a2a_mocks():
     sys.modules["a2a.server.events"] = events_mod
     sys.modules["a2a.server.tasks"] = tasks_mod
     sys.modules["a2a.types"] = types_mod
-    sys.modules["a2a.utils"] = utils_mod
+    sys.modules["a2a.helpers"] = helpers_mod
 
 
 def _make_langchain_mocks():
diff --git a/workspace/tests/test_a2a_executor.py b/workspace/tests/test_a2a_executor.py
index f393dfad..98ad19aa 100644
--- a/workspace/tests/test_a2a_executor.py
+++ b/workspace/tests/test_a2a_executor.py
@@ -1021,7 +1021,8 @@ async def test_cancel_emits_canceled_event(monkeypatch):
     types_mod = sys.modules["a2a.types"]
 
     class _TaskState:
-        canceled = "canceled"
+        # v1: TaskState enum uses SCREAMING_SNAKE_CASE keys
+        TASK_STATE_CANCELED = "canceled"
 
     class _TaskStatus:
         def __init__(self, state=None):
@@ -1046,4 +1047,4 @@ async def test_cancel_emits_canceled_event(monkeypatch):
     event = eq.enqueue_event.call_args[0][0]
     assert isinstance(event, _TaskStatusUpdateEvent), "expected a TaskStatusUpdateEvent"
     assert event.final is True, "cancel event must be marked final=True"
-    assert event.status.state == _TaskState.canceled, "cancel event must have state=canceled"
+    assert event.status.state == _TaskState.TASK_STATE_CANCELED, "cancel event must have state=TASK_STATE_CANCELED"
diff --git a/workspace/tests/test_hermes_executor.py b/workspace/tests/test_hermes_executor.py
index 2269bf2c..0b9070e3 100644
--- a/workspace/tests/test_hermes_executor.py
+++ b/workspace/tests/test_hermes_executor.py
@@ -653,7 +653,7 @@ async def test_cancel_emits_canceled_event():
     import a2a.types as a2a_types
 
     class _TaskState:
-        canceled = "canceled"
+        TASK_STATE_CANCELED = "canceled"  # a2a-sdk v1 enum name
 
     class _TaskStatus:
         def __init__(self, state):
@@ -675,7 +675,7 @@ async def test_cancel_emits_canceled_event():
     eq.enqueue_event.assert_called_once()
     event = eq.enqueue_event.call_args[0][0]
     assert isinstance(event, _TaskStatusUpdateEvent)
-    assert event.status.state == "canceled"
+    assert event.status.state == _TaskState.TASK_STATE_CANCELED
     assert event.final is True