diff --git a/strix/config/config.py b/strix/config/config.py
index a602658..636c8bf 100644
--- a/strix/config/config.py
+++ b/strix/config/config.py
@@ -19,6 +19,18 @@ class Config:
     strix_llm_max_retries = "5"
     strix_memory_compressor_timeout = "30"
     llm_timeout = "300"
+    _LLM_CANONICAL_NAMES = (
+        "strix_llm",
+        "llm_api_key",
+        "llm_api_base",
+        "openai_api_base",
+        "litellm_base_url",
+        "ollama_api_base",
+        "strix_reasoning_effort",
+        "strix_llm_max_retries",
+        "strix_memory_compressor_timeout",
+        "llm_timeout",
+    )
 
     # Tool & Feature Configuration
     perplexity_api_key = None
@@ -45,6 +57,20 @@ class Config:
     def tracked_vars(cls) -> list[str]:
         return [name.upper() for name in cls._tracked_names()]
 
+    @classmethod
+    def _llm_env_vars(cls) -> set[str]:
+        return {name.upper() for name in cls._LLM_CANONICAL_NAMES}
+
+    @classmethod
+    def _llm_env_changed(cls, saved_env: dict[str, Any]) -> bool:
+        for var_name in cls._llm_env_vars():
+            current = os.getenv(var_name)
+            if current is None:
+                continue
+            if saved_env.get(var_name) != current:
+                return True
+        return False
+
     @classmethod
     def get(cls, name: str) -> str | None:
         env_name = name.upper()
@@ -88,10 +114,24 @@ class Config:
     def apply_saved(cls) -> dict[str, str]:
         saved = cls.load()
         env_vars = saved.get("env", {})
+        if not isinstance(env_vars, dict):
+            env_vars = {}
+        cleared_vars = {
+            var_name
+            for var_name in cls.tracked_vars()
+            if var_name in os.environ and os.environ.get(var_name) == ""
+        }
+        if cleared_vars:
+            for var_name in cleared_vars:
+                env_vars.pop(var_name, None)
+            cls.save({"env": env_vars})
+        if cls._llm_env_changed(env_vars):
+            cls.save({"env": {}})
+            return {}
         applied = {}
 
         for var_name, var_value in env_vars.items():
-            if var_name in cls.tracked_vars() and not os.getenv(var_name):
+            if var_name in cls.tracked_vars() and var_name not in os.environ:
                 os.environ[var_name] = var_value
                 applied[var_name] = var_value