Enhance resource template to support values with slashes (Fix #159)

src/mcp/server/fastmcp/resources/templates.py

@@ -55,7 +55,7 @@ def from_function(
     def matches(self, uri: str) -> dict[str, Any] | None:
         """Check if URI matches template and extract parameters."""
         # Convert template to regex pattern
-        pattern = self.uri_template.replace("{", "(?P<").replace("}", ">[^/]+)")
+        pattern = self.uri_template.replace("{", "(?P<").replace("}", ">.+)")
         match = re.match(f"^{pattern}$", uri)
         if match:
             return match.groupdict()

tests/issues/test_141_resource_templates.py

@@ -58,11 +58,6 @@ def get_user_profile_missing(user_id: str) -> str:
     with pytest.raises(ValueError, match="Unknown resource"):
         await mcp.read_resource("resource://users/123/posts")  # Missing post_id
 
-    with pytest.raises(ValueError, match="Unknown resource"):
-        await mcp.read_resource(
-            "resource://users/123/posts/456/extra"
-        )  # Extra path component
-
 
 @pytest.mark.anyio
 async def test_resource_template_client_interaction():

tests/server/fastmcp/resources/test_resource_template.py

@@ -46,6 +46,25 @@ def my_func(key: str, value: int) -> dict:
         assert template.matches("test://foo") is None
         assert template.matches("other://foo/123") is None
 
+    def test_template_matches_slashes_in_value(self):
+        """Test matching URIs against a template, the value containing slashes."""
+
+        def my_func(path: str) -> dict:
+            return {"path": path}
+
+        template = ResourceTemplate.from_function(
+            fn=my_func,
+            uri_template="test://content/{path}",
+            name="test",
+        )
+
+        # Valid match
+        params = template.matches("test://content/path/with/slashes")
+        assert params == {"path": "path/with/slashes"}
+
+        # No match
+        assert template.matches("test://content/") is None
+
     @pytest.mark.anyio
     async def test_create_resource(self):
         """Test creating a resource from a template."""