test: reproduce #1574

Github-Issue: #1574

Author: felixweinberger

tests/issues/test_1574_resource_uri_validation.py

@@ -0,0 +1,85 @@
+"""Tests for issue #1574: Python SDK incorrectly validates Resource URIs.
+
+The Python SDK uses Pydantic's AnyUrl for URI fields, which rejects relative paths
+like 'users/me' that are valid according to the MCP spec and accepted by the
+TypeScript SDK.
+
+The spec defines uri fields as plain strings with no JSON Schema format validation.
+"""
+
+from mcp import types
+
+
+class TestResourceUriValidation:
+    """Test that Resource URI fields accept all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """
+        REPRODUCER: Relative paths like 'users/me' should be accepted.
+
+        Currently fails with:
+        ValidationError: Input should be a valid URL, relative URL without a base
+        """
+        # This should NOT raise - relative paths are valid per MCP spec
+        resource = types.Resource(name="test", uri="users/me")
+        assert str(resource.uri) == "users/me"
+
+    def test_custom_scheme_uri(self):
+        """Custom scheme URIs should be accepted."""
+        resource = types.Resource(name="test", uri="custom://resource")
+        assert str(resource.uri) == "custom://resource"
+
+    def test_file_url(self):
+        """File URLs should be accepted."""
+        resource = types.Resource(name="test", uri="file:///path/to/file")
+        assert str(resource.uri) == "file:///path/to/file"
+
+    def test_http_url(self):
+        """HTTP URLs should be accepted."""
+        resource = types.Resource(name="test", uri="https://example.com/resource")
+        assert str(resource.uri) == "https://example.com/resource"
+
+
+class TestReadResourceRequestParamsUri:
+    """Test that ReadResourceRequestParams.uri accepts all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """Relative paths should be accepted in read requests."""
+        params = types.ReadResourceRequestParams(uri="users/me")
+        assert str(params.uri) == "users/me"
+
+
+class TestResourceContentsUri:
+    """Test that ResourceContents.uri accepts all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """Relative paths should be accepted in resource contents."""
+        contents = types.TextResourceContents(uri="users/me", text="content")
+        assert str(contents.uri) == "users/me"
+
+
+class TestSubscribeRequestParamsUri:
+    """Test that SubscribeRequestParams.uri accepts all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """Relative paths should be accepted in subscribe requests."""
+        params = types.SubscribeRequestParams(uri="users/me")
+        assert str(params.uri) == "users/me"
+
+
+class TestUnsubscribeRequestParamsUri:
+    """Test that UnsubscribeRequestParams.uri accepts all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """Relative paths should be accepted in unsubscribe requests."""
+        params = types.UnsubscribeRequestParams(uri="users/me")
+        assert str(params.uri) == "users/me"
+
+
+class TestResourceUpdatedNotificationParamsUri:
+    """Test that ResourceUpdatedNotificationParams.uri accepts all valid MCP URIs."""
+
+    def test_relative_path_uri(self):
+        """Relative paths should be accepted in resource updated notifications."""
+        params = types.ResourceUpdatedNotificationParams(uri="users/me")
+        assert str(params.uri) == "users/me"