Backport: Support for Resource and ResourceTemplate metadata (#1928)

Co-authored-by: Jacem Elwaar <jacem@mcpappsbuilders.com>

tests/server/fastmcp/resources/test_function_resources.py

@@ -155,3 +155,38 @@ class TestFunctionResource:
         assert resource.mime_type == "text/plain"
         assert resource.name == "test"
         assert resource.uri == AnyUrl("function://test")
+
+
+class TestFunctionResourceMetadata:
+    def test_from_function_with_metadata(self):
+        # from_function() accepts meta dict and stores it on the resource for static resources
+
+        def get_data() -> str:  # pragma: no cover
+            return "test data"
+
+        metadata = {"cache_ttl": 300, "tags": ["data", "readonly"]}
+
+        resource = FunctionResource.from_function(
+            fn=get_data,
+            uri="resource://data",
+            meta=metadata,
+        )
+
+        assert resource.meta is not None
+        assert resource.meta == metadata
+        assert resource.meta["cache_ttl"] == 300
+        assert "data" in resource.meta["tags"]
+        assert "readonly" in resource.meta["tags"]
+
+    def test_from_function_without_metadata(self):
+        # meta parameter is optional and defaults to None for backward compatibility
+
+        def get_data() -> str:  # pragma: no cover
+            return "test data"
+
+        resource = FunctionResource.from_function(
+            fn=get_data,
+            uri="resource://data",
+        )
+
+        assert resource.meta is None

tests/server/fastmcp/resources/test_resource_manager.py

@@ -134,3 +134,43 @@ class TestResourceManager:
         resources = manager.list_resources()
         assert len(resources) == 2
         assert resources == [resource1, resource2]
+
+
+class TestResourceManagerMetadata:
+    """Test ResourceManager Metadata"""
+
+    def test_add_template_with_metadata(self):
+        """Test that ResourceManager.add_template() accepts and passes meta parameter."""
+
+        manager = ResourceManager()
+
+        def get_item(id: str) -> str:  # pragma: no cover
+            return f"Item {id}"
+
+        metadata = {"source": "database", "cached": True}
+
+        template = manager.add_template(
+            fn=get_item,
+            uri_template="resource://items/{id}",
+            meta=metadata,
+        )
+
+        assert template.meta is not None
+        assert template.meta == metadata
+        assert template.meta["source"] == "database"
+        assert template.meta["cached"] is True
+
+    def test_add_template_without_metadata(self):
+        """Test that ResourceManager.add_template() works without meta parameter."""
+
+        manager = ResourceManager()
+
+        def get_item(id: str) -> str:  # pragma: no cover
+            return f"Item {id}"
+
+        template = manager.add_template(
+            fn=get_item,
+            uri_template="resource://items/{id}",
+        )
+
+        assert template.meta is None

tests/server/fastmcp/resources/test_resource_template.py

@@ -258,3 +258,50 @@ class TestResourceTemplateAnnotations:
         # Verify the resource works correctly
         content = await resource.read()
         assert content == "Item 123"
+
+
+class TestResourceTemplateMetadata:
+    """Test ResourceTemplate meta handling."""
+
+    def test_template_from_function_with_metadata(self):
+        """Test that ResourceTemplate.from_function() accepts and stores meta parameter."""
+
+        def get_user(user_id: str) -> str:  # pragma: no cover
+            return f"User {user_id}"
+
+        metadata = {"requires_auth": True, "rate_limit": 100}
+
+        template = ResourceTemplate.from_function(
+            fn=get_user,
+            uri_template="resource://users/{user_id}",
+            meta=metadata,
+        )
+
+        assert template.meta is not None
+        assert template.meta == metadata
+        assert template.meta["requires_auth"] is True
+        assert template.meta["rate_limit"] == 100
+
+    @pytest.mark.anyio
+    async def test_template_created_resources_inherit_metadata(self):
+        """Test that resources created from templates inherit meta from template."""
+
+        def get_item(item_id: str) -> str:
+            return f"Item {item_id}"
+
+        metadata = {"category": "inventory", "cacheable": True}
+
+        template = ResourceTemplate.from_function(
+            fn=get_item,
+            uri_template="resource://items/{item_id}",
+            meta=metadata,
+        )
+
+        # Create a resource from the template
+        resource = await template.create_resource("resource://items/123", {"item_id": "123"})
+
+        # The resource should inherit the template's metadata
+        assert resource.meta is not None
+        assert resource.meta == metadata
+        assert resource.meta["category"] == "inventory"
+        assert resource.meta["cacheable"] is True

tests/server/fastmcp/resources/test_resources.py

@@ -193,3 +193,41 @@ class TestAnnotationsValidation:
         # Invalid roles should raise validation error
         with pytest.raises(Exception):  # Pydantic validation error
             Annotations(audience=["invalid_role"])  # type: ignore
+
+
+class TestResourceMetadata:
+    """Test metadata field on base Resource class."""
+
+    def test_resource_with_metadata(self):
+        """Test that Resource base class accepts meta parameter."""
+
+        def dummy_func() -> str:  # pragma: no cover
+            return "data"
+
+        metadata = {"version": "1.0", "category": "test"}
+
+        resource = FunctionResource(
+            uri=AnyUrl("resource://test"),
+            name="test",
+            fn=dummy_func,
+            meta=metadata,
+        )
+
+        assert resource.meta is not None
+        assert resource.meta == metadata
+        assert resource.meta["version"] == "1.0"
+        assert resource.meta["category"] == "test"
+
+    def test_resource_without_metadata(self):
+        """Test that meta field defaults to None."""
+
+        def dummy_func() -> str:  # pragma: no cover
+            return "data"
+
+        resource = FunctionResource(
+            uri=AnyUrl("resource://test"),
+            name="test",
+            fn=dummy_func,
+        )
+
+        assert resource.meta is None