Merge pull request #824 from 0xYiliu/fix/issue-783-fallback-alias-resolution

fix: resolve fallback model alias parsing for issue #783

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")
+	}
+}

pkg/providers/fallback.go

@@ -43,11 +43,26 @@ func NewFallbackChain(cooldown *CooldownTracker) *FallbackChain {
 
 // ResolveCandidates parses model config into a deduplicated candidate list.
 func ResolveCandidates(cfg ModelConfig, defaultProvider string) []FallbackCandidate {
+	return ResolveCandidatesWithLookup(cfg, defaultProvider, nil)
+}
+
+func ResolveCandidatesWithLookup(
+	cfg ModelConfig,
+	defaultProvider string,
+	lookup func(raw string) (resolved string, ok bool),
+) []FallbackCandidate {
 	seen := make(map[string]bool)
 	var candidates []FallbackCandidate
 
 	addCandidate := func(raw string) {
-		ref := ParseModelRef(raw, defaultProvider)
+		candidateRaw := strings.TrimSpace(raw)
+		if lookup != nil {
+			if resolved, ok := lookup(candidateRaw); ok {
+				candidateRaw = resolved
+			}
+		}
+
+		ref := ParseModelRef(candidateRaw, defaultProvider)
 		if ref == nil {
 			return
 		}

pkg/providers/fallback_test.go

@@ -453,6 +453,75 @@ func TestResolveCandidates_EmptyPrimary(t *testing.T) {
 	}
 }
 
+func TestResolveCandidatesWithLookup_AliasResolvesToNestedModel(t *testing.T) {
+	cfg := ModelConfig{
+		Primary:   "step-3.5-flash",
+		Fallbacks: nil,
+	}
+
+	lookup := func(raw string) (string, bool) {
+		if raw == "step-3.5-flash" {
+			return "openrouter/stepfun/step-3.5-flash:free", true
+		}
+		return "", false
+	}
+
+	candidates := ResolveCandidatesWithLookup(cfg, "", lookup)
+	if len(candidates) != 1 {
+		t.Fatalf("candidates = %d, want 1", len(candidates))
+	}
+	if candidates[0].Provider != "openrouter" {
+		t.Fatalf("provider = %q, want openrouter", candidates[0].Provider)
+	}
+	if candidates[0].Model != "stepfun/step-3.5-flash:free" {
+		t.Fatalf("model = %q, want stepfun/step-3.5-flash:free", candidates[0].Model)
+	}
+}
+
+func TestResolveCandidatesWithLookup_DeduplicateAfterLookup(t *testing.T) {
+	cfg := ModelConfig{
+		Primary:   "step-3.5-flash",
+		Fallbacks: []string{"openrouter/stepfun/step-3.5-flash:free"},
+	}
+
+	lookup := func(raw string) (string, bool) {
+		if raw == "step-3.5-flash" {
+			return "openrouter/stepfun/step-3.5-flash:free", true
+		}
+		return "", false
+	}
+
+	candidates := ResolveCandidatesWithLookup(cfg, "", lookup)
+	if len(candidates) != 1 {
+		t.Fatalf("candidates = %d, want 1", len(candidates))
+	}
+}
+
+func TestResolveCandidatesWithLookup_AliasWithoutProtocolUsesDefaultProvider(t *testing.T) {
+	cfg := ModelConfig{
+		Primary:   "glm-5",
+		Fallbacks: nil,
+	}
+
+	lookup := func(raw string) (string, bool) {
+		if raw == "glm-5" {
+			return "glm-5", true
+		}
+		return "", false
+	}
+
+	candidates := ResolveCandidatesWithLookup(cfg, "openai", lookup)
+	if len(candidates) != 1 {
+		t.Fatalf("candidates = %d, want 1", len(candidates))
+	}
+	if candidates[0].Provider != "openai" {
+		t.Fatalf("provider = %q, want openai", candidates[0].Provider)
+	}
+	if candidates[0].Model != "glm-5" {
+		t.Fatalf("model = %q, want glm-5", candidates[0].Model)
+	}
+}
+
 func TestFallbackExhaustedError_Message(t *testing.T) {
 	e := &FallbackExhaustedError{
 		Attempts: []FallbackAttempt{