diff --git a/hermes_cli/main.py b/hermes_cli/main.py
index 3bd6afa54f72a..54ccf6ca80b97 100644
--- a/hermes_cli/main.py
+++ b/hermes_cli/main.py
@@ -1274,6 +1274,8 @@ def _model_flow_custom(config):
             cfg["model"] = model
         model["provider"] = "custom"
         model["base_url"] = effective_url
+        if effective_key:
+            model["api_key"] = effective_key
         model.pop("api_mode", None)  # let runtime auto-detect from URL
         save_config(cfg)
         deactivate_provider()