fix(auth): normalize redirect URI URL subclasses

Author: he-yufeng

src/mcp/shared/auth.py

@@ -67,6 +67,16 @@ class OAuthClientMetadata(BaseModel):
     software_id: str | None = None
     software_version: str | None = None
 
+    @field_validator("redirect_uris", mode="before")
+    @classmethod
+    def _coerce_redirect_uris_to_any_url(cls, v: object) -> object:
+        # Pydantic v2 keeps AnyUrl subclasses such as AnyHttpUrl as-is, while
+        # AnyUrl equality is type-strict. Store the declared base type so later
+        # redirect_uri membership checks compare URLs, not URL wrapper classes.
+        if isinstance(v, list | tuple):
+            return [str(item) if isinstance(item, AnyUrl) else item for item in v]
+        return v
+
     @field_validator(
         "client_uri",
         "logo_uri",

tests/shared/test_auth.py

@@ -1,9 +1,9 @@
 """Tests for OAuth 2.0 shared code."""
 
 import pytest
-from pydantic import ValidationError
+from pydantic import AnyHttpUrl, AnyUrl, ValidationError
 
-from mcp.shared.auth import OAuthClientInformationFull, OAuthClientMetadata, OAuthMetadata
+from mcp.shared.auth import InvalidRedirectUriError, OAuthClientInformationFull, OAuthClientMetadata, OAuthMetadata
 
 
 def test_oauth():
@@ -130,6 +130,19 @@ def test_information_full_inherits_coercion():
     assert info.jwks_uri is None
 
 
+def test_redirect_uris_normalize_any_url_subtypes():
+    info = OAuthClientInformationFull(
+        client_id="abc123",
+        redirect_uris=[AnyHttpUrl("https://example.com/callback")],
+    )
+
+    assert info.validate_redirect_uri(AnyUrl("https://example.com/callback")) == AnyUrl("https://example.com/callback")
+    assert info.model_dump(mode="json")["redirect_uris"] == ["https://example.com/callback"]
+
+    with pytest.raises(InvalidRedirectUriError):
+        info.validate_redirect_uri(AnyUrl("https://example.com/other"))
+
+
 def test_invalid_non_empty_url_still_rejected():
     """Coercion must only touch empty strings — garbage URLs still raise."""
     data = {