revert: copilotkit 0.1.94 AG-UI upgrade (#754) — incompatible protocol

echo/agent/main.py

@@ -5,7 +5,7 @@
 from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 
-from copilotkit import CopilotKitRemoteEndpoint, LangGraphAGUIAgent
+from copilotkit import CopilotKitRemoteEndpoint, LangGraphAgent
 from copilotkit.integrations.fastapi import handler as copilotkit_handler
 
 from agent import create_agent_graph
@@ -57,12 +57,13 @@ async def copilotkit_endpoint(request: Request, project_id: str, path: Optional[
     request.scope.setdefault("path_params", {})
     request.scope["path_params"]["path"] = path or ""
 
-    agent = LangGraphAGUIAgent(
+    agent = LangGraphAgent(
         name="default",
         description="Echo Agentic Chat default agent",
         graph=create_agent_graph(project_id=project_id, bearer_token=bearer_token),
     )
-    # Pass agents as a callable (CopilotKit rejects a literal list here).
+    # CopilotKit currently rejects LangGraphAgent only for literal list inputs.
+    # Supplying a callable preserves expected runtime behavior in this SDK version.
     endpoint = CopilotKitRemoteEndpoint(agents=lambda _context: [agent])
     return await copilotkit_handler(request, endpoint)
 

echo/agent/pyproject.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 description = "Isolated CopilotKit runtime for Echo Agentic Chat"
 requires-python = ">=3.11"
 dependencies = [
-    "copilotkit>=0.1.94,<0.2",
+    "copilotkit>=0.1.77",
     "langgraph>=0.2",
     "langchain-google-vertexai>=3.2.2",
     "google-auth>=2.35",

echo/agent/tests/test_main_routes.py

@@ -25,7 +25,7 @@ async def _fake_handler(request, _endpoint):
 
 def test_copilotkit_root_post_rewrites_to_default_path(monkeypatch):
     monkeypatch.setattr(main, "copilotkit_handler", _fake_handler)
-    monkeypatch.setattr(main, "LangGraphAGUIAgent", _DummyLangGraphAgent)
+    monkeypatch.setattr(main, "LangGraphAgent", _DummyLangGraphAgent)
     monkeypatch.setattr(main, "CopilotKitRemoteEndpoint", _DummyEndpoint)
 
     client = TestClient(main.app)
@@ -42,7 +42,7 @@ def test_copilotkit_root_post_rewrites_to_default_path(monkeypatch):
 
 def test_copilotkit_nested_path_is_preserved(monkeypatch):
     monkeypatch.setattr(main, "copilotkit_handler", _fake_handler)
-    monkeypatch.setattr(main, "LangGraphAGUIAgent", _DummyLangGraphAgent)
+    monkeypatch.setattr(main, "LangGraphAgent", _DummyLangGraphAgent)
     monkeypatch.setattr(main, "CopilotKitRemoteEndpoint", _DummyEndpoint)
 
     client = TestClient(main.app)