fix(tui): allow empty json smoke

internal/cli/app.go

@@ -1083,23 +1083,35 @@ func (a *App) runTUI(ctx context.Context, args []string) error {
 		rt, err = a.openLocalRuntimeReadOnly(ctx)
 	}
 	if err != nil {
+		if !interactive && errors.Is(err, os.ErrNotExist) {
+			cfg := config.Default()
+			if cfgErr := cfg.Normalize(); cfgErr != nil {
+				return cfgErr
+			}
+			sort, sortErr := resolveTUISort(*sortMode, cfg)
+			if sortErr != nil {
+				return sortErr
+			}
+			return a.writeOutput("tui", emptyClusterBrowserPayload(ctx, cfg, cfg.DBPath, sort, minSize, limit, *hideClosed), true)
+		}
 		return err
 	}
 	defer rt.Store.Close()
 
 	repo, inferred, err := a.resolveOptionalRepository(ctx, rt, fs.Args())
 	if err != nil {
+		if !interactive && len(fs.Args()) == 0 && strings.Contains(err.Error(), "no local repositories found") {
+			sort, sortErr := resolveTUISort(*sortMode, rt.Config)
+			if sortErr != nil {
+				return sortErr
+			}
+			return a.writeOutput("tui", emptyClusterBrowserPayload(ctx, rt.Config, rt.SourceDBPath, sort, minSize, limit, *hideClosed), true)
+		}
 		return err
 	}
-	sort := strings.TrimSpace(*sortMode)
-	if sort == "" {
-		sort = strings.TrimSpace(rt.Config.TUI.DefaultSort)
-	}
-	if sort == "" {
-		sort = "size"
-	}
-	if sort != "recent" && sort != "oldest" && sort != "size" {
-		return usageErr(fmt.Errorf("unsupported sort %q", sort))
+	sort, err := resolveTUISort(*sortMode, rt.Config)
+	if err != nil {
+		return err
 	}
 	showClosed := !*hideClosed || *includeClosed
 
@@ -1154,6 +1166,38 @@ func (a *App) runTUI(ctx context.Context, args []string) error {
 	return a.runInteractiveTUI(ctx, rt.Store, repo.ID, payload)
 }
 
+func resolveTUISort(raw string, cfg config.Config) (string, error) {
+	sort := strings.TrimSpace(raw)
+	if sort == "" {
+		sort = strings.TrimSpace(cfg.TUI.DefaultSort)
+	}
+	if sort == "" {
+		sort = "size"
+	}
+	if sort != "recent" && sort != "oldest" && sort != "size" {
+		return "", usageErr(fmt.Errorf("unsupported sort %q", sort))
+	}
+	return sort, nil
+}
+
+func emptyClusterBrowserPayload(ctx context.Context, cfg config.Config, sourceDBPath, sort string, minSize, limit int, hideClosed bool) clusterBrowserPayload {
+	if strings.TrimSpace(sourceDBPath) == "" {
+		sourceDBPath = cfg.DBPath
+	}
+	return clusterBrowserPayload{
+		Mode:           "cluster-browser",
+		DBSource:       databaseSourceKind(sourceDBPath),
+		DBLocation:     databaseSourceLocation(ctx, sourceDBPath),
+		Sort:           sort,
+		MinSize:        minSize,
+		Limit:          limit,
+		HideClosed:     hideClosed,
+		EmbedModel:     cfg.OpenAI.EmbedModel,
+		EmbeddingBasis: cfg.EmbeddingBasis,
+		Clusters:       []store.ClusterSummary{},
+	}
+}
+
 func databaseSourceKind(dbPath string) string {
 	if _, ok := portableStoreRoot(dbPath); ok {
 		return "remote"

internal/cli/app_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
@@ -1022,6 +1023,60 @@ func TestTUIInfersRepository(t *testing.T) {
 	}
 }
 
+func TestTUIJSONUsesDefaultsWhenConfigMissing(t *testing.T) {
+	ctx := context.Background()
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "missing.toml")
+	t.Setenv("GITCRAWL_DB_PATH", filepath.Join(dir, "missing.db"))
+
+	run := New()
+	var stdout bytes.Buffer
+	run.Stdout = &stdout
+	if err := run.Run(ctx, []string{"--config", configPath, "tui", "--json"}); err != nil {
+		t.Fatalf("tui: %v", err)
+	}
+	var payload map[string]any
+	if err := json.Unmarshal(stdout.Bytes(), &payload); err != nil {
+		t.Fatalf("decode tui payload: %v\n%s", err, stdout.String())
+	}
+	if payload["mode"] != "cluster-browser" {
+		t.Fatalf("mode = %#v", payload["mode"])
+	}
+	clusters, ok := payload["clusters"].([]any)
+	if !ok || len(clusters) != 0 {
+		t.Fatalf("clusters = %#v", payload["clusters"])
+	}
+	if _, err := os.Stat(configPath); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("config file should not be created, stat err=%v", err)
+	}
+}
+
+func TestTUIJSONHandlesEmptyStoreWithoutRepository(t *testing.T) {
+	ctx := context.Background()
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.toml")
+	dbPath := filepath.Join(dir, "gitcrawl.db")
+	app := New()
+	if err := app.Run(ctx, []string{"--config", configPath, "init", "--db", dbPath}); err != nil {
+		t.Fatalf("init: %v", err)
+	}
+
+	run := New()
+	var stdout bytes.Buffer
+	run.Stdout = &stdout
+	if err := run.Run(ctx, []string{"--config", configPath, "tui", "--json"}); err != nil {
+		t.Fatalf("tui: %v", err)
+	}
+	var payload map[string]any
+	if err := json.Unmarshal(stdout.Bytes(), &payload); err != nil {
+		t.Fatalf("decode tui payload: %v\n%s", err, stdout.String())
+	}
+	clusters, ok := payload["clusters"].([]any)
+	if !ok || len(clusters) != 0 {
+		t.Fatalf("clusters = %#v", payload["clusters"])
+	}
+}
+
 func TestTUIRequiresInteractiveTerminalByDefault(t *testing.T) {
 	ctx := context.Background()
 	dir := t.TempDir()