fix(#4728): persist provider-only default-model changes end to end

api/config.py

@@ -3555,7 +3555,7 @@ def _apply_advanced_model_options(model_cfg: dict, advanced: dict | None) -> Non
         model_cfg["api_key"] = api_key
 
 
-def set_hermes_default_model(model_id: str, advanced: dict | None = None) -> dict:
+def set_hermes_default_model(model_id: str, provider: str | None = None, advanced: dict | None = None) -> dict:
     """Persist the Hermes default model in config.yaml and reload runtime config."""
     selected_model = str(model_id or "").strip()
     if not selected_model:
@@ -3572,6 +3572,7 @@ def set_hermes_default_model(model_id: str, advanced: dict | None = None) -> dic
             model_cfg = {}
 
         previous_provider = str(model_cfg.get("provider") or "").strip()
+        requested_provider = str(provider or "").strip()
         resolved_model, resolved_provider, resolved_base_url = resolve_model_provider(
             selected_model
         )
@@ -3585,7 +3586,7 @@ def set_hermes_default_model(model_id: str, advanced: dict | None = None) -> dic
         # CLI-shaped bare form via `_applyModelToDropdown()`'s normalising
         # matcher — see `static/panels.js` (#895).
         persisted_model = str(resolved_model or selected_model).strip()
-        persisted_provider = str(resolved_provider or previous_provider or "").strip()
+        persisted_provider = str(requested_provider or resolved_provider or previous_provider or "").strip()
         # Never persist the bogus ``local`` value — see #1384. The auto-detect
         # block in ``_build_available_models_uncached`` was rewriting unknown
         # loopback hosts to ``provider: "local"``, which is not registered and
@@ -3617,7 +3618,7 @@ def set_hermes_default_model(model_id: str, advanced: dict | None = None) -> dic
     # it triggers a live provider fetch (up to 8s) that blocks the HTTP response
     # to the browser, causing a visible freeze on every Settings save (#895).
     invalidate_models_cache()
-    return {"ok": True, "model": persisted_model}
+    return {"ok": True, "model": persisted_model, "provider": persisted_provider or None}
 
 
 # ── Auxiliary model configuration ──────────────────────────────────────────

api/routes.py

@@ -10943,7 +10943,8 @@ def handle_post(handler, parsed) -> bool:
     if parsed.path == "/api/default-model":
         try:
             advanced = body.get("advanced") if isinstance(body, dict) else None
-            return j(handler, set_hermes_default_model(body.get("model"), advanced=advanced))
+            provider = body.get("provider") if isinstance(body, dict) else None
+            return j(handler, set_hermes_default_model(body.get("model"), provider=provider, advanced=advanced))
         except ValueError as e:
             return bad(handler, str(e))
         except RuntimeError as e:
@@ -10964,7 +10965,7 @@ def handle_post(handler, parsed) -> bool:
                 return bad(handler, str(exc), status=400)
         if scope == "main":
             try:
-                return j(handler, set_hermes_default_model(model, advanced=advanced))
+                return j(handler, set_hermes_default_model(model, provider=provider, advanced=advanced))
             except ValueError as exc:
                 return bad(handler, str(exc), status=400)
         return bad(handler, f"unknown scope: {scope}", status=400)

static/panels.js

@@ -9795,7 +9795,7 @@ async function saveSettings(andClose){
       const saved=await api('/api/settings',{method:'POST',body:JSON.stringify(payload)});
       if(modelChanged && model){
         try{
-          await api('/api/default-model',{method:'POST',body:JSON.stringify({model})});
+          await api('/api/default-model',{method:'POST',body:JSON.stringify({model,provider:modelState.model_provider||null})});
           body.default_model=model;
           body.default_model_provider=(modelState&&modelState.model===model)?(modelState.model_provider||null):null;
         }catch(_modelErr){
@@ -9825,7 +9825,7 @@ async function saveSettings(andClose){
     const saved=await api('/api/settings',{method:'POST',body:JSON.stringify(body)});
     if(modelChanged && model){
       try{
-        await api('/api/default-model',{method:'POST',body:JSON.stringify({model})});
+        await api('/api/default-model',{method:'POST',body:JSON.stringify({model,provider:modelState.model_provider||null})});
         body.default_model=model;
         body.default_model_provider=(modelState&&modelState.model===model)?(modelState.model_provider||null):null;
       }catch(_modelErr){

tests/test_auxiliary_models_settings.py

@@ -474,6 +474,23 @@ class TestAuxiliaryModelsBackend:
         assert "reasoning_effort: none" in text
         assert "DUMMY_KEY_DO_NOT_PRINT" in text
 
+    def test_set_hermes_default_model_persists_explicit_provider_override(self, monkeypatch, tmp_path):
+        from api import config
+
+        config_path = tmp_path / "config.yaml"
+        config_path.write_text("model:\n  provider: openai\n  default: gpt-5.5\n", encoding="utf-8")
+        monkeypatch.setattr(config, "_get_config_path", lambda: config_path)
+        monkeypatch.setattr(config, "reload_config", lambda: None)
+        monkeypatch.setattr(config, "invalidate_models_cache", lambda: None)
+        monkeypatch.setattr(config, "resolve_model_provider", lambda model: (model, "", None))
+
+        result = config.set_hermes_default_model("gpt-5.5", provider="anthropic")
+
+        assert result["ok"] is True
+        assert result["provider"] == "anthropic"
+        text = config_path.read_text(encoding="utf-8")
+        assert "provider: anthropic" in text
+
     def test_set_auxiliary_model_persists_advanced_options(self, monkeypatch, tmp_path):
         """Gear-modal payload should persist supported per-slot options."""
         from api import config

tests/test_new_chat_default_model_frontend.py

@@ -162,6 +162,7 @@ def test_save_settings_syncs_default_model_provider_with_saved_model():
     autosave_block = panels_js[panels_js.index("const pwField=$('settingsPassword');"):panels_js.index("if(!pwDirty&&!modelDirty){", panels_js.index("const pwField=$('settingsPassword');")) + 24]
 
     assert "_captureModelDropdownSelection($('settingsModel'))" in save_block
+    assert "JSON.stringify({model,provider:modelState.model_provider||null})" in save_block
     assert "body.default_model_provider=(modelState&&modelState.model===model)?(modelState.model_provider||null):null;" in save_block
     assert "const modelChanged=(model||'')!==(_settingsHermesDefaultModelOnOpen||'')||((modelState.model_provider||null)!==(_settingsHermesDefaultModelProviderOnOpen||null));" in save_block
     assert "if(Object.prototype.hasOwnProperty.call(body,'default_model_provider')) window._activeProvider=body.default_model_provider||null;" in apply_saved_block