diff --git a/node-setup/action.yml b/node-setup/action.yml
index 5f1d063..a5673f2 100644
--- a/node-setup/action.yml
+++ b/node-setup/action.yml
@@ -275,7 +275,8 @@ runs:
       with:
         node-version: ${{ steps.version.outputs.detected-version }}
         registry-url: ${{ inputs.registry-url }}
-        cache: false
+        # Note: cache parameter removed for actions/setup-node@v6 compatibility
+        # Caching is handled separately via common-cache action (step: Cache Dependencies)
 
     - name: Enable Corepack
       id: corepack
diff --git a/validate-inputs/tests/test_conventions.py b/validate-inputs/tests/test_conventions.py
index 954c2b0..6512f91 100644
--- a/validate-inputs/tests/test_conventions.py
+++ b/validate-inputs/tests/test_conventions.py
@@ -48,9 +48,47 @@ class TestConventionsValidator:
         rules = validator._rules
         assert rules["action_type"] == "nonexistent-action"
         assert rules["required_inputs"] == []
-        assert isinstance(rules["optional_inputs"], dict)
+        assert isinstance(rules["optional_inputs"], list)
         assert isinstance(rules["conventions"], dict)
 
+    def test_load_rules_with_dict_optional_inputs(self, tmp_path):
+        """Test backward compatibility with dict format for optional_inputs."""
+        # Create a rules file with legacy dict format for optional_inputs
+        rules_file = tmp_path / "legacy_rules.yml"
+        rules_file.write_text("""
+action_type: legacy-action
+required_inputs: []
+optional_inputs:
+  foo: int
+  bar: str
+  baz:
+    type: boolean
+    validator: boolean
+conventions: {}
+overrides: {}
+""")
+        # Load rules and verify conventions are built from dict keys
+        validator = ConventionBasedValidator("legacy-action")
+        rules = validator.load_rules(rules_file)
+
+        # Verify optional_inputs is preserved as-is from YAML
+        assert "optional_inputs" in rules
+        assert isinstance(rules["optional_inputs"], dict)
+
+        # Verify conventions were auto-generated from optional_inputs dict keys
+        assert "conventions" in rules
+        assert isinstance(rules["conventions"], dict)
+        conventions_keys = set(rules["conventions"].keys())
+        optional_keys = set(rules["optional_inputs"].keys())
+        assert conventions_keys == optional_keys, (
+            f"Conventions keys {conventions_keys} should match optional_inputs keys {optional_keys}"
+        )
+
+        # Verify each key from the dict is in conventions
+        assert "foo" in rules["conventions"]
+        assert "bar" in rules["conventions"]
+        assert "baz" in rules["conventions"]
+
     def test_load_rules_with_custom_path(self, tmp_path):
         """Test loading rules from custom path."""
         rules_file = tmp_path / "custom_rules.yml"
diff --git a/validate-inputs/validators/conventions.py b/validate-inputs/validators/conventions.py
index ab19904..01a73ab 100644
--- a/validate-inputs/validators/conventions.py
+++ b/validate-inputs/validators/conventions.py
@@ -82,7 +82,7 @@ class ConventionBasedValidator(BaseValidator):
             return {
                 "action_type": self.action_type,
                 "required_inputs": [],
-                "optional_inputs": {},
+                "optional_inputs": [],
                 "conventions": {},
                 "overrides": {},
             }
@@ -93,16 +93,27 @@ class ConventionBasedValidator(BaseValidator):
 
             # Ensure all expected keys exist
             rules.setdefault("required_inputs", [])
-            rules.setdefault("optional_inputs", {})
+            rules.setdefault("optional_inputs", [])
             rules.setdefault("conventions", {})
             rules.setdefault("overrides", {})
 
             # Build conventions from optional_inputs if not explicitly set
             if not rules["conventions"] and rules["optional_inputs"]:
                 conventions = {}
-                for input_name, input_config in rules["optional_inputs"].items():
-                    # Try to infer validator type from the input name or pattern
-                    conventions[input_name] = self._infer_validator_type(input_name, input_config)
+                optional_inputs = rules["optional_inputs"]
+
+                # Handle both list and dict formats for optional_inputs
+                if isinstance(optional_inputs, list):
+                    # List format: just input names
+                    for input_name in optional_inputs:
+                        conventions[input_name] = self._infer_validator_type(input_name, {})
+                elif isinstance(optional_inputs, dict):
+                    # Dict format: input names with config
+                    for input_name, input_config in optional_inputs.items():
+                        conventions[input_name] = self._infer_validator_type(
+                            input_name, input_config
+                        )
+
                 rules["conventions"] = conventions
 
             return rules
@@ -110,7 +121,7 @@ class ConventionBasedValidator(BaseValidator):
             return {
                 "action_type": self.action_type,
                 "required_inputs": [],
-                "optional_inputs": {},
+                "optional_inputs": [],
                 "conventions": {},
                 "overrides": {},
             }
@@ -285,7 +296,7 @@ class ConventionBasedValidator(BaseValidator):
         # Get conventions and overrides from rules
         conventions = self._rules.get("conventions", {})
         overrides = self._rules.get("overrides", {})
-        optional_inputs = self._rules.get("optional_inputs", {})
+        optional_inputs = self._rules.get("optional_inputs", [])
         required_inputs = self.get_required_inputs()
 
         # Validate each input