Fix Vercel

Author: DouweM

pydantic_ai_slim/pydantic_ai/ui/vercel_ai/_adapter.py

@@ -57,7 +57,7 @@ def encode_event(self, event: BaseChunk, accept: str | None = None) -> str:
     @classmethod
     async def validate_request(cls, request: Request) -> RequestData:
         """Validate a Vercel AI request."""
-        return request_data_ta.validate_json(await request.json())
+        return request_data_ta.validate_json(await request.body())
 
     @classmethod
     async def dispatch_request(

pydantic_ai_slim/pydantic_ai/ui/vercel_ai/_request_types.py

@@ -4,9 +4,9 @@
 https://github.com/vercel/ai/blob/ai%405.0.34/packages/ai/src/ui/ui-messages.ts
 """
 
-from typing import Any, Literal
+from typing import Annotated, Any, Literal
 
-from pydantic import TypeAdapter
+from pydantic import Discriminator, TypeAdapter
 
 from ._utils import CamelBaseModel, ProviderMetadata
 
@@ -56,15 +56,24 @@ class UIMessage(CamelBaseModel):
     parts: list[UIPart]
 
 
-class SubmitMessage(CamelBaseModel):
+class SubmitMessage(CamelBaseModel, extra='allow'):
     """Submit message request."""
 
     trigger: Literal['submit-message'] = 'submit-message'
     id: str
     messages: list[UIMessage]
 
 
-RequestData = SubmitMessage
+class RegenerateMessage(CamelBaseModel, extra='allow'):
+    """Ask the agent to regenerate a message."""
+
+    trigger: Literal['regenerate-message']
+    id: str
+    messages: list[UIMessage]
+    message_id: str
+
+
+RequestData = Annotated[SubmitMessage | RegenerateMessage, Discriminator('trigger')]
 
 # Type adapter for parsing requests
 request_data_ta: TypeAdapter[RequestData] = TypeAdapter(RequestData)

tests/test_vercel_ai.py

@@ -7,8 +7,6 @@
 
 from pydantic_ai import Agent
 from pydantic_ai.builtin_tools import WebSearchTool
-from pydantic_ai.models.openai import OpenAIResponsesModel
-from pydantic_ai.providers.openai import OpenAIProvider
 from pydantic_ai.ui.vercel_ai import VercelAIAdapter
 from pydantic_ai.ui.vercel_ai._request_types import (
     SubmitMessage,
@@ -17,7 +15,12 @@
     UIMessage,
 )
 
-from .conftest import IsStr
+from .conftest import IsStr, try_import
+
+with try_import() as openai_import_successful:
+    from pydantic_ai.models.openai import OpenAIResponsesModel
+    from pydantic_ai.providers.openai import OpenAIProvider
+
 
 pytestmark = [
     pytest.mark.anyio,
@@ -31,6 +34,7 @@
 ]
 
 
+@pytest.mark.skipif(not openai_import_successful(), reason='OpenAI not installed')
 async def test_run(allow_model_requests: None, openai_api_key: str):
     model = OpenAIResponsesModel('gpt-5', provider=OpenAIProvider(api_key=openai_api_key))
     agent = Agent(model=model, builtin_tools=[WebSearchTool()])