diff --git a/tests/test_tui_gateway_server.py b/tests/test_tui_gateway_server.py
index 1daf77bd2f..43a368ce81 100644
--- a/tests/test_tui_gateway_server.py
+++ b/tests/test_tui_gateway_server.py
@@ -85,11 +85,21 @@ def test_status_callback_accepts_single_message_argument():
 
 def test_resolve_model_uses_inference_model_env(monkeypatch):
     monkeypatch.delenv("HERMES_MODEL", raising=False)
-    monkeypatch.setenv("HERMES_INFERENCE_MODEL", "anthropic/claude-sonnet-4.6")
+    monkeypatch.setenv("HERMES_INFERENCE_MODEL", " anthropic/claude-sonnet-4.6\n")
 
     assert server._resolve_model() == "anthropic/claude-sonnet-4.6"
 
 
+def test_resolve_model_strips_config_model(monkeypatch):
+    monkeypatch.delenv("HERMES_MODEL", raising=False)
+    monkeypatch.delenv("HERMES_INFERENCE_MODEL", raising=False)
+    monkeypatch.setattr(
+        server, "_load_cfg", lambda: {"model": {"default": " nous/hermes-test "}}
+    )
+
+    assert server._resolve_model() == "nous/hermes-test"
+
+
 def test_startup_runtime_uses_tui_provider_env(monkeypatch):
     monkeypatch.setenv("HERMES_MODEL", "nous/hermes-test")
     monkeypatch.setenv("HERMES_TUI_PROVIDER", "nous")
@@ -457,6 +467,55 @@ def test_config_set_model_syncs_inference_provider_env(monkeypatch):
     assert os.environ["HERMES_INFERENCE_PROVIDER"] == "anthropic"
 
 
+def test_config_set_model_syncs_tui_provider_env(monkeypatch):
+    class Agent:
+        model = "gpt-5.3-codex"
+        provider = "openai-codex"
+        base_url = ""
+        api_key = ""
+
+        def switch_model(self, **kwargs):
+            self.model = kwargs["new_model"]
+            self.provider = kwargs["new_provider"]
+
+    agent = Agent()
+    server._sessions["sid"] = _session(agent=agent)
+    monkeypatch.setenv("HERMES_TUI_PROVIDER", "openai-codex")
+    monkeypatch.setattr(server, "_restart_slash_worker", lambda session: None)
+    monkeypatch.setattr(server, "_emit", lambda *args, **kwargs: None)
+
+    def fake_switch_model(**kwargs):
+        return types.SimpleNamespace(
+            success=True,
+            new_model="anthropic/claude-sonnet-4.6",
+            target_provider="anthropic",
+            api_key="key",
+            base_url="https://api.anthropic.com",
+            api_mode="anthropic_messages",
+            warning_message="",
+        )
+
+    monkeypatch.setattr("hermes_cli.model_switch.switch_model", fake_switch_model)
+
+    try:
+        resp = server.handle_request(
+            {
+                "id": "1",
+                "method": "config.set",
+                "params": {
+                    "session_id": "sid",
+                    "key": "model",
+                    "value": "anthropic/claude-sonnet-4.6 --provider anthropic",
+                },
+            }
+        )
+
+        assert resp["result"]["value"] == "anthropic/claude-sonnet-4.6"
+        assert os.environ["HERMES_TUI_PROVIDER"] == "anthropic"
+    finally:
+        server._sessions.clear()
+
+
 def test_config_set_personality_rejects_unknown_name(monkeypatch):
     monkeypatch.setattr(
         server,
diff --git a/tui_gateway/server.py b/tui_gateway/server.py
index fa01a68fb4..9f188de645 100644
--- a/tui_gateway/server.py
+++ b/tui_gateway/server.py
@@ -560,14 +560,17 @@ def resolve_skin() -> dict:
 
 
 def _resolve_model() -> str:
-    env = os.environ.get("HERMES_MODEL", "") or os.environ.get("HERMES_INFERENCE_MODEL", "")
+    env = (
+        os.environ.get("HERMES_MODEL", "")
+        or os.environ.get("HERMES_INFERENCE_MODEL", "")
+    ).strip()
     if env:
         return env
     m = _load_cfg().get("model", "")
     if isinstance(m, dict):
-        return m.get("default", "")
+        return str(m.get("default", "") or "").strip()
     if isinstance(m, str) and m:
-        return m
+        return m.strip()
     return "anthropic/claude-sonnet-4"
 
 
@@ -773,6 +776,8 @@ def _apply_model_switch(sid: str, session: dict, raw_input: str) -> dict:
     # original one persisted in config or env.
     if result.target_provider:
         os.environ["HERMES_INFERENCE_PROVIDER"] = result.target_provider
+        if os.environ.get("HERMES_TUI_PROVIDER"):
+            os.environ["HERMES_TUI_PROVIDER"] = result.target_provider
     if persist_global:
         _persist_model_switch(result)
     return {"value": result.new_model, "warning": result.warning_message or ""}