Route friendly Seedance aliases to configured upstream models

Popiai can emit human-facing model names such as seedance2.0, while the upstream channel table is keyed by the canonical doubao-seedance model ids. Normalize Seedance aliases at the server gateway boundary so CLI, Popiai, and any direct gateway-compatible client can keep using friendly names without sending an unconfigured model id upstream.

Constraint: NewAPI channel selection requires canonical doubao-seedance-* model ids.

Rejected: Fix only the PopiArt CLI default path | Popiai and other clients can still send explicit friendly aliases.

Confidence: high

Scope-risk: narrow

Directive: Keep alias normalization at the server boundary before expanding client-specific mappings.

Tested: go test ./internal/server -run 'Seedance|VideoGenerations'

Tested: go test ./...

internal/server/newapi.go

@@ -2339,7 +2339,7 @@ func (c *newAPIClient) submitSeedanceVideoTask(ctx context.Context, token, model
 }
 
 func buildSeedanceVideoGenerationPayload(modelID string, input map[string]any) (map[string]any, error) {
-	modelID = strings.TrimSpace(modelID)
+	modelID = normalizeSeedanceVideoModelID(modelID)
 	if modelID == "" {
 		return nil, errors.New("Seedance model id is required")
 	}
@@ -2401,6 +2401,36 @@ func buildSeedanceVideoGenerationPayload(modelID string, input map[string]any) (
 	return payload, nil
 }
 
+func normalizeSeedanceVideoModelID(modelID string) string {
+	modelID = strings.TrimSpace(modelID)
+	if modelID == "" {
+		return ""
+	}
+
+	normalized := strings.ToLower(strings.NewReplacer("_", "-", ".", "-").Replace(modelID))
+	normalized = strings.Join(strings.Fields(normalized), "")
+
+	switch normalized {
+	case "seedance2-0", "seedance-2-0":
+		return "doubao-seedance-2-0-260128"
+	case "seedance2-0-fast", "seedance-2-0-fast":
+		return "doubao-seedance-2-0-fast-260128"
+	case "seedance1-5", "seedance-1-5", "seedance1-5-pro", "seedance-1-5-pro":
+		return "doubao-seedance-1-5-pro-251215"
+	case "seedance1-0-pro", "seedance-1-0-pro":
+		return "doubao-seedance-1-0-pro-250528"
+	case "seedance1-0-lite-t2v", "seedance-1-0-lite-t2v":
+		return "doubao-seedance-1-0-lite-t2v"
+	case "seedance1-0-lite-i2v", "seedance-1-0-lite-i2v":
+		return "doubao-seedance-1-0-lite-i2v"
+	}
+
+	if strings.HasPrefix(normalized, "seedance-") {
+		return "doubao-" + normalized
+	}
+	return modelID
+}
+
 func (c *newAPIClient) submitJimengVideoTask(ctx context.Context, token, modelID string, input map[string]any) (string, error) {
 	if !c.enabled() {
 		return "", errors.New("PopiNewAPI base URL is not configured")

internal/server/video_test.go

@@ -405,6 +405,33 @@ func TestSubmitSeedanceVideoTaskUsesVideoGenerationsEndpoint(t *testing.T) {
 	}
 }
 
+func TestSubmitSeedanceVideoTaskNormalizesFriendlyModelAlias(t *testing.T) {
+	var gotBody map[string]any
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
+			t.Fatalf("decode request body: %v", err)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"id":"task_seedance_alias_123","status":"submitted"}`))
+	}))
+	defer srv.Close()
+
+	client := newNewAPIClient(Config{NewAPIBaseURL: srv.URL})
+	taskID, err := client.submitSeedanceVideoTask(context.Background(), "sk-test", "seedance2.0", map[string]any{
+		"prompt":   "keep the motion natural",
+		"duration": 5,
+	})
+	if err != nil {
+		t.Fatalf("submitSeedanceVideoTask: %v", err)
+	}
+	if taskID != "task_seedance_alias_123" {
+		t.Fatalf("unexpected task id: %q", taskID)
+	}
+	if gotBody["model"] != "doubao-seedance-2-0-260128" {
+		t.Fatalf("expected canonical Seedance model, got %#v", gotBody["model"])
+	}
+}
+
 func TestHandleVideoGenerationsRelaysSeedanceRequest(t *testing.T) {
 	var gotBody map[string]any
 	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -466,6 +493,48 @@ func TestHandleVideoGenerationsRelaysSeedanceRequest(t *testing.T) {
 	}
 }
 
+func TestHandleVideoGenerationsNormalizesSeedanceAlias(t *testing.T) {
+	var gotBody map[string]any
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
+			t.Fatalf("decode upstream body: %v", err)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"code":"success","data":{"task_id":"task_seedance_alias_direct_123","status":"PENDING"}}`))
+	}))
+	defer upstream.Close()
+
+	server, err := NewWithConfig(Config{
+		NewAPIBaseURL: upstream.URL,
+		SQLitePath:    filepath.Join(t.TempDir(), "popiart.db"),
+		SkillhubDir:   makeEmptySkillhub(t),
+		SessionSecret: "test-secret",
+	})
+	if err != nil {
+		t.Fatalf("NewWithConfig: %v", err)
+	}
+	token, _, ok, err := server.store.createSession("sk-test-upstream")
+	if err != nil {
+		t.Fatalf("createSession: %v", err)
+	}
+	if !ok {
+		t.Fatal("expected session creation to succeed")
+	}
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/video/generations", strings.NewReader(`{"model":"seedance2.0","prompt":"ping"}`))
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	server.Handler().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusAccepted {
+		t.Fatalf("expected 202, got %d body=%s", rec.Code, rec.Body.String())
+	}
+	if gotBody["model"] != "doubao-seedance-2-0-260128" {
+		t.Fatalf("expected canonical Seedance model, got %#v", gotBody["model"])
+	}
+}
+
 func TestHandleVideoGenerationFetchSurfacesLastFrameURL(t *testing.T) {
 	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodGet || r.URL.Path != "/v1/video/generations/task_seedance_direct_123" {