diff --git a/tests/test_factor_rules.py b/tests/test_factor_rules.py
new file mode 100644
index 00000000..71b2a3bd
--- /dev/null
+++ b/tests/test_factor_rules.py
@@ -0,0 +1,73 @@
+import importlib.util
+import json
+import tempfile
+import unittest
+from pathlib import Path
+
+MODULE_PATH = Path(__file__).resolve().parents[1] / "tradingagents" / "agents" / "utils" / "factor_rules.py"
+SPEC = importlib.util.spec_from_file_location("factor_rules", MODULE_PATH)
+factor_rules = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(factor_rules)
+
+_candidate_rule_paths = factor_rules._candidate_rule_paths
+load_factor_rules = factor_rules.load_factor_rules
+
+
+class FactorRulesPathTests(unittest.TestCase):
+    def test_candidate_paths_are_deduplicated(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            project_dir = Path(tmpdir)
+            examples_dir = project_dir / "examples"
+            examples_dir.mkdir()
+            rule_path = examples_dir / "factor_rules.json"
+            rule_path.write_text(json.dumps({"rules": []}), encoding="utf-8")
+
+            config = {
+                "project_dir": str(project_dir),
+                "factor_rules_path": str(rule_path),
+            }
+
+            original_env = factor_rules.os.environ.get("TRADINGAGENTS_FACTOR_RULES_PATH")
+            factor_rules.os.environ["TRADINGAGENTS_FACTOR_RULES_PATH"] = str(rule_path)
+            try:
+                paths = _candidate_rule_paths(config)
+            finally:
+                if original_env is None:
+                    factor_rules.os.environ.pop("TRADINGAGENTS_FACTOR_RULES_PATH", None)
+                else:
+                    factor_rules.os.environ["TRADINGAGENTS_FACTOR_RULES_PATH"] = original_env
+
+            self.assertEqual(paths.count(rule_path.resolve()), 1)
+
+    def test_load_factor_rules_accepts_rules_object(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            project_dir = Path(tmpdir)
+            examples_dir = project_dir / "examples"
+            examples_dir.mkdir()
+            rule_path = examples_dir / "factor_rules.json"
+            payload = {"rules": [{"name": "Value", "signal": "bullish"}]}
+            rule_path.write_text(json.dumps(payload), encoding="utf-8")
+
+            rules, loaded_path = load_factor_rules({"project_dir": str(project_dir)})
+            self.assertEqual(rules, payload["rules"])
+            self.assertEqual(Path(loaded_path), rule_path.resolve())
+
+    def test_outside_project_rule_path_is_rejected(self):
+        with tempfile.TemporaryDirectory() as project_tmp, tempfile.TemporaryDirectory() as outside_tmp:
+            project_dir = Path(project_tmp)
+            outside_path = Path(outside_tmp) / "factor_rules.json"
+            outside_path.write_text(json.dumps({"rules": [{"name": "Outside"}]}), encoding="utf-8")
+
+            rules, loaded_path = load_factor_rules(
+                {
+                    "project_dir": str(project_dir),
+                    "factor_rules_path": str(outside_path),
+                }
+            )
+
+            self.assertEqual(rules, [])
+            self.assertIsNone(loaded_path)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tradingagents/agents/utils/factor_rules.py b/tradingagents/agents/utils/factor_rules.py
index a71dcf53..d1c1ff3b 100644
--- a/tradingagents/agents/utils/factor_rules.py
+++ b/tradingagents/agents/utils/factor_rules.py
@@ -33,6 +33,7 @@ def _candidate_rule_paths(config: Optional[Dict[str, Any]] = None) -> List[Path]
     )
 
     safe_candidates = []
+    seen = set()
     for candidate in candidates:
         try:
             resolved = candidate.resolve()
@@ -40,8 +41,12 @@ def _candidate_rule_paths(config: Optional[Dict[str, Any]] = None) -> List[Path]
             continue
         if resolved.name not in _ALLOWED_RULE_FILENAMES:
             continue
-        if any(parent == resolved.parent or parent in resolved.parents for parent in allowed_dirs):
-            safe_candidates.append(resolved)
+        if not any(parent == resolved.parent or parent in resolved.parents for parent in allowed_dirs):
+            continue
+        if resolved in seen:
+            continue
+        seen.add(resolved)
+        safe_candidates.append(resolved)
     return safe_candidates