diff --git a/pydantic_ai_slim/pydantic_ai/ui/_web/api.py b/pydantic_ai_slim/pydantic_ai/ui/_web/api.py
index ac42fc529a..132827d248 100644
--- a/pydantic_ai_slim/pydantic_ai/ui/_web/api.py
+++ b/pydantic_ai_slim/pydantic_ai/ui/_web/api.py
@@ -152,7 +152,7 @@ async def health(request: Request) -> Response:
 
     async def post_chat(request: Request) -> Response:
         """Handle chat requests via Vercel AI Adapter."""
-        adapter = await VercelAIAdapter[AgentDepsT, OutputDataT].from_request(request, agent=agent)
+        adapter = await VercelAIAdapter[AgentDepsT, OutputDataT].from_request(request, agent=agent, sdk_version=6)
         extra_data = ChatRequestExtra.model_validate(adapter.run_input.__pydantic_extra__)
 
         if error := validate_request_options(extra_data, model_ids, allowed_tool_ids):
@@ -163,6 +163,7 @@ async def post_chat(request: Request) -> Response:
         streaming_response = await VercelAIAdapter[AgentDepsT, OutputDataT].dispatch_request(
             request,
             agent=agent,
+            sdk_version=6,
             model=model_ref,
             builtin_tools=request_builtin_tools,
             deps=deps,
diff --git a/pydantic_ai_slim/pydantic_ai/ui/_web/app.py b/pydantic_ai_slim/pydantic_ai/ui/_web/app.py
index aede5e5d7c..4591dcf5a2 100644
--- a/pydantic_ai_slim/pydantic_ai/ui/_web/app.py
+++ b/pydantic_ai_slim/pydantic_ai/ui/_web/app.py
@@ -25,7 +25,7 @@
         'you can use the `web` optional group — `pip install "pydantic-ai-slim[web]"`'
     ) from _import_error
 
-CHAT_UI_VERSION = '1.0.0'
+CHAT_UI_VERSION = '2.0.0'
 DEFAULT_HTML_URL = f'https://cdn.jsdelivr.net/npm/@pydantic/ai-chat-ui@{CHAT_UI_VERSION}/dist/index.html'
 
 AgentDepsT = TypeVar('AgentDepsT')