merge with recent branch

Author: SoldierSacha

src/mcp/client/auth/__init__.py

@@ -5,19 +5,23 @@
 """
 
 from mcp.client.auth.oauth2 import (
+    ClientCredentialsProvider,
     OAuthClientProvider,
     OAuthFlowError,
     OAuthRegistrationError,
     OAuthTokenError,
     PKCEParameters,
+    TokenExchangeProvider,
     TokenStorage,
 )
 
 __all__ = [
+    "ClientCredentialsProvider",
     "OAuthClientProvider",
     "OAuthFlowError",
     "OAuthRegistrationError",
     "OAuthTokenError",
     "PKCEParameters",
+    "TokenExchangeProvider",
     "TokenStorage",
 ]

src/mcp/server/auth/handlers/register.py

@@ -68,7 +68,19 @@ async def handle(self, request: Request) -> Response:
                     ),
                     status_code=400,
                 )
+
+        # Validate redirect_uris is provided for authorization_code grant type
         grant_types_set: set[str] = set(client_metadata.grant_types)
+        if "authorization_code" in grant_types_set and (
+            client_metadata.redirect_uris is None or len(client_metadata.redirect_uris) == 0
+        ):
+            return PydanticJSONResponse(
+                content=RegistrationErrorResponse(
+                    error="invalid_client_metadata",
+                    error_description="redirect_uris: Field required",
+                ),
+                status_code=400,
+            )
         required_sets = [
             {"authorization_code", "refresh_token"},
             {"client_credentials"},