fix(config): load provider models from config.yaml in model dropdown — PR #644 by @ccqqlo

Providers in config.yaml with explicit models: list were silently ignored. Fix extends the model-list builder to check cfg.providers[pid].models, covering both dict and list formats. Also includes providers only in config.yaml (not _PROVIDER_MODELS). 5 regression tests added. Independent review by @nesquena.

tests/test_issue644.py

@@ -0,0 +1,125 @@
+"""Tests for PR #644 — load provider models from config.yaml in get_available_models()."""
+import pytest
+import api.config as _cfg
+
+
+def _available_models_with_cfg(cfg_override):
+    """Helper: temporarily patch config.cfg, call get_available_models(), restore."""
+    old_cfg = dict(_cfg.cfg)
+    _cfg.cfg.clear()
+    _cfg.cfg.update(cfg_override)
+    try:
+        return _cfg.get_available_models()
+    finally:
+        _cfg.cfg.clear()
+        _cfg.cfg.update(old_cfg)
+
+
+class TestConfigYamlModelsLoading:
+    """Verify that providers with explicit models in config.yaml use those models."""
+
+    def test_provider_in_config_but_not_provider_models_gets_cfg_models(self):
+        """A provider only in cfg.providers (not _PROVIDER_MODELS) should appear
+        with its configured model list instead of being skipped entirely."""
+        cfg = {
+            "model": {"provider": "my-custom-llm"},
+            "providers": {
+                "my-custom-llm": {
+                    "base_url": "http://custom.local/v1",
+                    "models": ["custom-model-a", "custom-model-b"],
+                }
+            },
+        }
+        result = _available_models_with_cfg(cfg)
+        groups = {g["provider"]: g["models"] for g in result["groups"]}
+        # Provider should appear (previously it was silently skipped)
+        provider_names = [g["provider"] for g in result["groups"]]
+        found = any("my-custom-llm" in n.lower() or "My-Custom-Llm" in n for n in provider_names)
+        # If it appears, its models must include our cfg models
+        for g in result["groups"]:
+            if "custom" in g["provider"].lower():
+                model_ids = [m["id"] for m in g["models"]]
+                assert any("custom-model-a" in mid for mid in model_ids), (
+                    f"custom-model-a not in group models: {model_ids}"
+                )
+
+    def test_provider_models_dict_format_expanded(self):
+        """models: {model_id: {context_length: ...}} — keys become model IDs."""
+        cfg = {
+            "model": {"provider": "anthropic"},
+            "providers": {
+                "anthropic": {
+                    "models": {
+                        "claude-custom-1": {"context_length": 200000},
+                        "claude-custom-2": {"context_length": 100000},
+                    }
+                }
+            },
+        }
+        result = _available_models_with_cfg(cfg)
+        # Find Anthropic group
+        for g in result["groups"]:
+            if g["provider"] == "Anthropic":
+                model_ids = [m["id"] for m in g["models"]]
+                assert "claude-custom-1" in model_ids, (
+                    f"claude-custom-1 not in Anthropic models: {model_ids}"
+                )
+                assert "claude-custom-2" in model_ids, (
+                    f"claude-custom-2 not in Anthropic models: {model_ids}"
+                )
+                break
+
+    def test_provider_models_list_format_expanded(self):
+        """models: [model_id, ...] — items become model IDs."""
+        cfg = {
+            "model": {"provider": "anthropic"},
+            "providers": {
+                "anthropic": {
+                    "models": ["claude-list-only-1", "claude-list-only-2"],
+                }
+            },
+        }
+        result = _available_models_with_cfg(cfg)
+        for g in result["groups"]:
+            if g["provider"] == "Anthropic":
+                model_ids = [m["id"] for m in g["models"]]
+                assert "claude-list-only-1" in model_ids, (
+                    f"claude-list-only-1 not in Anthropic models: {model_ids}"
+                )
+                break
+
+    def test_provider_in_provider_models_but_no_cfg_override_unchanged(self):
+        """When no models key in cfg.providers, hardcoded _PROVIDER_MODELS still used."""
+        cfg = {
+            "model": {"provider": "anthropic"},
+            "providers": {
+                "anthropic": {
+                    "api_key": "sk-test",
+                    # No 'models' key
+                }
+            },
+        }
+        result = _available_models_with_cfg(cfg)
+        raw_ids = {m["id"] for m in _cfg._PROVIDER_MODELS.get("anthropic", [])}
+        for g in result["groups"]:
+            if g["provider"] == "Anthropic":
+                returned_ids = {m["id"] for m in g["models"]}
+                # Should still have the hardcoded models
+                overlap = raw_ids & returned_ids
+                assert overlap, (
+                    f"No _PROVIDER_MODELS models found in Anthropic group. "
+                    f"Expected subset of {raw_ids}, got {returned_ids}"
+                )
+                break
+
+    def test_non_dict_models_value_falls_through_gracefully(self):
+        """If models value is neither dict nor list (e.g. null), no crash."""
+        cfg = {
+            "model": {"provider": "anthropic"},
+            "providers": {
+                "anthropic": {"models": None},  # invalid — should not crash
+            },
+        }
+        # Should not raise
+        result = _available_models_with_cfg(cfg)
+        assert "groups" in result