fix(agent): resolve fallback model aliases from model_list

pkg/agent/instance.go

@@ -92,7 +92,47 @@ func NewAgentInstance(
 		Primary:   model,
 		Fallbacks: fallbacks,
 	}
-	candidates := providers.ResolveCandidates(modelCfg, defaults.Provider)
+	resolveFromModelList := func(raw string) (string, bool) {
+		ensureProtocol := func(model string) string {
+			model = strings.TrimSpace(model)
+			if model == "" {
+				return ""
+			}
+			if strings.Contains(model, "/") {
+				return model
+			}
+			return "openai/" + model
+		}
+
+		raw = strings.TrimSpace(raw)
+		if raw == "" {
+			return "", false
+		}
+
+		if cfg != nil {
+			if mc, err := cfg.GetModelConfig(raw); err == nil && mc != nil && strings.TrimSpace(mc.Model) != "" {
+				return ensureProtocol(mc.Model), true
+			}
+
+			for i := range cfg.ModelList {
+				fullModel := strings.TrimSpace(cfg.ModelList[i].Model)
+				if fullModel == "" {
+					continue
+				}
+				if fullModel == raw {
+					return ensureProtocol(fullModel), true
+				}
+				_, modelID := providers.ExtractProtocol(fullModel)
+				if modelID == raw {
+					return ensureProtocol(fullModel), true
+				}
+			}
+		}
+
+		return "", false
+	}
+
+	candidates := providers.ResolveCandidatesWithLookup(modelCfg, defaults.Provider, resolveFromModelList)
 
 	return &AgentInstance{
 		ID:             agentID,

pkg/agent/instance_test.go

@@ -93,3 +93,77 @@ func TestNewAgentInstance_DefaultsTemperatureWhenUnset(t *testing.T) {
 		t.Fatalf("Temperature = %f, want %f", agent.Temperature, 0.7)
 	}
 }
+
+func TestNewAgentInstance_ResolveCandidatesFromModelListAlias(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "agent-instance-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace: tmpDir,
+				Model:     "step-3.5-flash",
+			},
+		},
+		ModelList: []config.ModelConfig{
+			{
+				ModelName: "step-3.5-flash",
+				Model:     "openrouter/stepfun/step-3.5-flash:free",
+				APIBase:   "https://openrouter.ai/api/v1",
+			},
+		},
+	}
+
+	provider := &mockProvider{}
+	agent := NewAgentInstance(nil, &cfg.Agents.Defaults, cfg, provider)
+
+	if len(agent.Candidates) != 1 {
+		t.Fatalf("len(Candidates) = %d, want 1", len(agent.Candidates))
+	}
+	if agent.Candidates[0].Provider != "openrouter" {
+		t.Fatalf("candidate provider = %q, want %q", agent.Candidates[0].Provider, "openrouter")
+	}
+	if agent.Candidates[0].Model != "stepfun/step-3.5-flash:free" {
+		t.Fatalf("candidate model = %q, want %q", agent.Candidates[0].Model, "stepfun/step-3.5-flash:free")
+	}
+}
+
+func TestNewAgentInstance_ResolveCandidatesFromModelListAliasWithoutProtocol(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "agent-instance-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace: tmpDir,
+				Model:     "glm-5",
+			},
+		},
+		ModelList: []config.ModelConfig{
+			{
+				ModelName: "glm-5",
+				Model:     "glm-5",
+				APIBase:   "https://api.z.ai/api/coding/paas/v4",
+			},
+		},
+	}
+
+	provider := &mockProvider{}
+	agent := NewAgentInstance(nil, &cfg.Agents.Defaults, cfg, provider)
+
+	if len(agent.Candidates) != 1 {
+		t.Fatalf("len(Candidates) = %d, want 1", len(agent.Candidates))
+	}
+	if agent.Candidates[0].Provider != "openai" {
+		t.Fatalf("candidate provider = %q, want %q", agent.Candidates[0].Provider, "openai")
+	}
+	if agent.Candidates[0].Model != "glm-5" {
+		t.Fatalf("candidate model = %q, want %q", agent.Candidates[0].Model, "glm-5")
+	}
+}