fix: graceful shutdown on ctrl-c and remove auto-open browser (#164)

## Summary

- Wire the signal context as `BaseContext` on `http.Server` so Ctrl-C
cancels all request contexts immediately, letting SSE handlers exit and
`Shutdown` complete promptly
- Thread `context.Context` through `SyncAll`/`ResyncAll` so
API-triggered syncs abort on cancellation instead of blocking shutdown
- Abort the resync DB swap when cancelled mid-run, preventing a partial
temp DB from replacing the original
- Skip post-cancel phases (OpenCode sync, skip-cache persist) in
`syncAllLocked` when aborted
- Remove auto-open browser feature; keep `-no-browser` flag registered
as a no-op for script compatibility

## Test plan

- [x] New regression test: cancel `ResyncAll` mid-run, verify original
DB preserved
- [x] `make test-short` passes
- [x] `make vet` passes
- [x] Manual: `./agentsview` responds to first Ctrl-C immediately

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: wesm

README.md

@@ -63,9 +63,8 @@ patterns over time.
 ## Usage
 
 ```bash
-agentsview              # start server, open browser
+agentsview              # start server
 agentsview -port 9090   # custom port
-agentsview -no-browser  # headless mode
 ```
 
 On startup, agentsview discovers sessions from all supported

cmd/agentsview/main.go

@@ -9,10 +9,8 @@ import (
 	"log"
 	"net/http"
 	"os"
-	"os/exec"
 	"os/signal"
 	"path/filepath"
-	"runtime"
 	"syscall"
 	"time"
 	_ "time/tzdata"
@@ -34,8 +32,6 @@ const (
 	periodicSyncInterval  = 15 * time.Minute
 	unwatchedPollInterval = 2 * time.Minute
 	watcherDebounce       = 500 * time.Millisecond
-	browserPollInterval   = 100 * time.Millisecond
-	browserPollAttempts   = 60
 )
 
 func main() {
@@ -94,7 +90,6 @@ Server flags:
   -tls-cert string    TLS certificate path for managed Caddy HTTPS mode
   -tls-key string     TLS key path for managed Caddy HTTPS mode
   -allowed-subnet str Client CIDR allowed to connect to the managed proxy
-  -no-browser         Don't open browser on startup
 
 Sync flags:
   -full              Force a full resync regardless of data version
@@ -190,16 +185,24 @@ func runServe(args []string) {
 	// Remove stale temp DB from a prior crashed resync.
 	cleanResyncTemp(cfg.DBPath)
 
+	ctx, stop := signal.NotifyContext(
+		context.Background(), os.Interrupt, syscall.SIGTERM,
+	)
+	defer stop()
+
 	engine := sync.NewEngine(database, sync.EngineConfig{
 		AgentDirs:               cfg.AgentDirs,
 		Machine:                 "local",
 		BlockedResultCategories: cfg.ResultContentBlockedCategories,
 	})
 
 	if database.NeedsResync() {
-		runInitialResync(engine)
+		runInitialResync(ctx, engine)
 	} else {
-		runInitialSync(engine)
+		runInitialSync(ctx, engine)
+	}
+	if ctx.Err() != nil {
+		return
 	}
 
 	stopWatcher, unwatchedDirs := startFileWatcher(cfg, engine)
@@ -257,13 +260,9 @@ func runServe(args []string) {
 			BuildDate: buildDate,
 		}),
 		server.WithDataDir(cfg.DataDir),
+		server.WithBaseContext(ctx),
 	)
 
-	ctx, stop := signal.NotifyContext(
-		context.Background(), os.Interrupt, syscall.SIGTERM,
-	)
-	defer stop()
-
 	serveErrCh := make(chan error, 1)
 	go func() {
 		serveErrCh <- srv.ListenAndServe()
@@ -342,10 +341,6 @@ func runServe(args []string) {
 		)
 	}
 
-	if !cfg.NoBrowser {
-		go openBrowser(publicURL)
-	}
-
 	var caddyErrCh <-chan error
 	if caddy != nil {
 		caddyErrCh = caddy.Err()
@@ -480,26 +475,30 @@ func cleanResyncTemp(dbPath string) {
 	}
 }
 
-func runInitialSync(engine *sync.Engine) {
+func runInitialSync(
+	ctx context.Context, engine *sync.Engine,
+) {
 	fmt.Println("Running initial sync...")
 	t := time.Now()
-	stats := engine.SyncAll(printSyncProgress)
+	stats := engine.SyncAll(ctx, printSyncProgress)
 	printSyncSummary(stats, t)
 }
 
-func runInitialResync(engine *sync.Engine) {
+func runInitialResync(
+	ctx context.Context, engine *sync.Engine,
+) {
 	fmt.Println("Data version changed, running full resync...")
 	t := time.Now()
-	stats := engine.ResyncAll(printSyncProgress)
+	stats := engine.ResyncAll(ctx, printSyncProgress)
 	printSyncSummary(stats, t)
 
-	// If resync was aborted (swap didn't happen), fall back
-	// to a normal incremental sync so the server starts with
-	// current file data rather than a potentially stale DB.
-	if stats.Aborted {
+	// If resync was aborted due to data issues (not
+	// cancellation), fall back to an incremental sync so
+	// the server starts with current data.
+	if stats.Aborted && ctx.Err() == nil {
 		fmt.Println("Resync incomplete, running incremental sync...")
 		t = time.Now()
-		fallback := engine.SyncAll(printSyncProgress)
+		fallback := engine.SyncAll(ctx, printSyncProgress)
 		printSyncSummary(fallback, t)
 	}
 }
@@ -610,7 +609,7 @@ func startPeriodicSync(engine *sync.Engine) {
 	defer ticker.Stop()
 	for range ticker.C {
 		log.Println("Running scheduled sync...")
-		engine.SyncAll(nil)
+		engine.SyncAll(context.Background(), nil)
 	}
 }
 
@@ -619,31 +618,6 @@ func startUnwatchedPoll(engine *sync.Engine) {
 	defer ticker.Stop()
 	for range ticker.C {
 		log.Println("Polling unwatched directories...")
-		engine.SyncAll(nil)
-	}
-}
-
-func openBrowser(url string) {
-	for range browserPollAttempts {
-		time.Sleep(browserPollInterval)
-		resp, err := http.Get(url + "/api/v1/stats")
-		if err == nil {
-			resp.Body.Close()
-			break
-		}
-	}
-
-	var cmd *exec.Cmd
-	switch runtime.GOOS {
-	case "darwin":
-		cmd = exec.Command("open", url)
-	case "linux":
-		cmd = exec.Command("xdg-open", url)
-	case "windows":
-		cmd = exec.Command("rundll32",
-			"url.dll,FileProtocolHandler", url)
-	default:
-		return
+		engine.SyncAll(context.Background(), nil)
 	}
-	_ = cmd.Run()
 }

cmd/agentsview/main_test.go

@@ -20,7 +20,6 @@ func TestMustLoadConfig(t *testing.T) {
 		wantPort      int
 		wantPublicURL string
 		wantProxyMode string
-		wantNoBrowser bool
 	}{
 		{
 			name:          "DefaultArgs",
@@ -29,7 +28,6 @@ func TestMustLoadConfig(t *testing.T) {
 			wantPort:      8080,
 			wantPublicURL: "",
 			wantProxyMode: "",
-			wantNoBrowser: false,
 		},
 		{
 			name:          "ExplicitFlags",
@@ -38,7 +36,6 @@ func TestMustLoadConfig(t *testing.T) {
 			wantPort:      9090,
 			wantPublicURL: "https://viewer.example.test:9443",
 			wantProxyMode: "caddy",
-			wantNoBrowser: true,
 		},
 		{
 			name:          "PartialFlags",
@@ -47,7 +44,6 @@ func TestMustLoadConfig(t *testing.T) {
 			wantPort:      3000,
 			wantPublicURL: "",
 			wantProxyMode: "",
-			wantNoBrowser: false,
 		},
 	}
 
@@ -68,9 +64,6 @@ func TestMustLoadConfig(t *testing.T) {
 			if cfg.Proxy.Mode != tt.wantProxyMode {
 				t.Errorf("Proxy.Mode = %q, want %q", cfg.Proxy.Mode, tt.wantProxyMode)
 			}
-			if cfg.NoBrowser != tt.wantNoBrowser {
-				t.Errorf("NoBrowser = %v, want %v", cfg.NoBrowser, tt.wantNoBrowser)
-			}
 
 			if cfg.DataDir == "" {
 				t.Error("DataDir should be set")

cmd/agentsview/sync.go

@@ -97,10 +97,11 @@ func runSync(args []string) {
 		Machine:   "local",
 	})
 
+	ctx := context.Background()
 	if cfg.Full || database.NeedsResync() {
-		runInitialResync(engine)
+		runInitialResync(ctx, engine)
 	} else {
-		runInitialSync(engine)
+		runInitialSync(ctx, engine)
 	}
 
 	fmt.Println()

desktop/src-tauri/src/lib.rs

@@ -104,14 +104,7 @@ fn spawn_sidecar(app: &App) -> Result<(CommandRx, CommandChild), DynError> {
     }
 
     Ok(command
-        .args([
-            "serve",
-            "-no-browser",
-            "-host",
-            HOST,
-            "-port",
-            port_arg.as_str(),
-        ])
+        .args(["serve", "-host", HOST, "-port", port_arg.as_str()])
         .spawn()?)
 }
 

internal/config/config.go

@@ -54,7 +54,6 @@ type ProxyConfig struct {
 type Config struct {
 	Host                 string         `json:"host"`
 	Port                 int            `json:"port"`
-	NoBrowser            bool           `json:"no_browser"`
 	DataDir              string         `json:"data_dir"`
 	DBPath               string         `json:"-"`
 	PublicURL            string         `json:"public_url,omitempty"`
@@ -422,8 +421,6 @@ func applyFlags(cfg *Config, fs *flag.FlagSet) {
 			cfg.Proxy.TLSKey = f.Value.String()
 		case "allowed-subnet":
 			cfg.Proxy.AllowedSubnets = splitFlagList(f.Value.String())
-		case "no-browser":
-			cfg.NoBrowser = f.Value.String() == "true"
 		}
 	})
 }

internal/server/events.go

@@ -218,12 +218,12 @@ func (s *Server) handleTriggerSync(
 	stream, err := NewSSEStream(w)
 	if err != nil {
 		// Non-streaming fallback
-		stats := s.engine.SyncAll(nil)
+		stats := s.engine.SyncAll(r.Context(), nil)
 		writeJSON(w, http.StatusOK, stats)
 		return
 	}
 
-	stats := s.engine.SyncAll(func(p syncpkg.Progress) {
+	stats := s.engine.SyncAll(r.Context(), func(p syncpkg.Progress) {
 		stream.SendJSON("progress", p)
 	})
 	stream.SendJSON("done", stats)
@@ -234,12 +234,12 @@ func (s *Server) handleTriggerResync(
 ) {
 	stream, err := NewSSEStream(w)
 	if err != nil {
-		stats := s.engine.ResyncAll(nil)
+		stats := s.engine.ResyncAll(r.Context(), nil)
 		writeJSON(w, http.StatusOK, stats)
 		return
 	}
 
-	stats := s.engine.ResyncAll(func(p syncpkg.Progress) {
+	stats := s.engine.ResyncAll(r.Context(), func(p syncpkg.Progress) {
 		stream.SendJSON("progress", p)
 	})
 	stream.SendJSON("done", stats)

internal/server/server.go

@@ -38,6 +38,11 @@ type Server struct {
 	version VersionInfo
 	dataDir string
 
+	// baseCtx, when set, is used as the base context for all
+	// incoming requests. Cancelling it causes SSE handlers to
+	// exit promptly, which unblocks graceful shutdown.
+	baseCtx context.Context
+
 	generateStreamFunc insight.GenerateStreamFunc
 	spaFS              fs.FS
 	spaHandler         http.Handler
@@ -92,6 +97,14 @@ func WithDataDir(dir string) Option {
 	return func(s *Server) { s.dataDir = dir }
 }
 
+// WithBaseContext sets the base context for all incoming HTTP
+// requests. When this context is cancelled, request contexts
+// are also cancelled, causing long-lived handlers (SSE) to
+// exit and unblocking graceful shutdown.
+func WithBaseContext(ctx context.Context) Option {
+	return func(s *Server) { s.baseCtx = ctx }
+}
+
 // WithUpdateChecker overrides the update check function,
 // allowing tests to substitute a deterministic stub.
 func WithUpdateChecker(f UpdateCheckFunc) Option {
@@ -521,6 +534,12 @@ func (s *Server) ListenAndServe() error {
 		ReadTimeout: 10 * time.Second,
 		IdleTimeout: 120 * time.Second,
 	}
+	if s.baseCtx != nil {
+		ctx := s.baseCtx
+		srv.BaseContext = func(_ net.Listener) context.Context {
+			return ctx
+		}
+	}
 	s.mu.Lock()
 	s.httpSrv = srv
 	s.mu.Unlock()

internal/server/server_test.go

@@ -2253,7 +2253,7 @@ func TestWatchSession_Events(t *testing.T) {
 		},
 		Machine: "test",
 	})
-	engine.SyncAll(nil)
+	engine.SyncAll(context.Background(), nil)
 
 	ctx, cancel := context.WithTimeout(
 		context.Background(), 5*time.Second,
@@ -2306,7 +2306,7 @@ func TestWatchSession_FileDisappearAndResolve(t *testing.T) {
 		},
 		Machine: "test",
 	})
-	engine.SyncAll(nil)
+	engine.SyncAll(context.Background(), nil)
 
 	ctx, cancel := context.WithTimeout(
 		context.Background(), 15*time.Second,

internal/server/timeout_test.go

@@ -29,7 +29,7 @@ func TestServerTimeouts(t *testing.T) {
 	)
 
 	// Seed the DB.
-	te.engine.SyncAll(nil)
+	te.engine.SyncAll(context.Background(), nil)
 
 	baseURL := te.listenAndServe(t)