Add HTTP Referer request header to Vercel AI Gateway provider (#2369)

Author: joshualipman123

pydantic_ai_slim/pydantic_ai/providers/vercel.py

@@ -98,10 +98,16 @@ def __init__(
                 'or pass the API key via `VercelProvider(api_key=...)` to use the Vercel provider.'
             )
 
+        default_headers = {'http-referer': 'https://ai.pydantic.dev/', 'x-title': 'pydantic-ai'}
+
         if openai_client is not None:
             self._client = openai_client
         elif http_client is not None:
-            self._client = AsyncOpenAI(base_url=self.base_url, api_key=api_key, http_client=http_client)
+            self._client = AsyncOpenAI(
+                base_url=self.base_url, api_key=api_key, http_client=http_client, default_headers=default_headers
+            )
         else:
             http_client = cached_async_http_client(provider='vercel')
-            self._client = AsyncOpenAI(base_url=self.base_url, api_key=api_key, http_client=http_client)
+            self._client = AsyncOpenAI(
+                base_url=self.base_url, api_key=api_key, http_client=http_client, default_headers=default_headers
+            )