diff --git a/.github/workflows/merge-main-into-compat.yml b/.github/workflows/merge-main-into-compat.yml
new file mode 100644
index 00000000..a9c4027f
--- /dev/null
+++ b/.github/workflows/merge-main-into-compat.yml
@@ -0,0 +1,39 @@
+name: Cherry-pick into Compat
+
+on:
+  push:
+    tags:
+      - v*
+    paths:
+      - ".github/workflows/merge-main-into-compat.yml"
+
+jobs:
+  cherry-pick:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Configure git user
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+      - name: Cherry-pick commits from last tag
+        run: |
+          git fetch origin compat
+          git checkout compat
+          CURRENT_TAG=${{ github.ref_name }}
+          PREV_TAG=$(git describe --tags --abbrev=0 $CURRENT_TAG^ 2>/dev/null || echo "")
+
+          if [ -z "$PREV_TAG" ]; then
+            echo "No previous tag found. Cherry-picking all commits up to $CURRENT_TAG"
+            git rev-list --reverse --no-merges $CURRENT_TAG | xargs -r git cherry-pick
+          else
+            echo "Cherry-picking commits from $PREV_TAG to $CURRENT_TAG"
+            git rev-list --reverse --no-merges $PREV_TAG..$CURRENT_TAG | xargs -r git cherry-pick
+          fi
+      - name: Push compat
+        run: |
+          git push origin compat
diff --git a/goutils b/goutils
index 6c698b1d..cb0f79b5 160000
--- a/goutils
+++ b/goutils
@@ -1 +1 @@
-Subproject commit 6c698b1d55d04591f362db585a6fbfe1a8893f56
+Subproject commit cb0f79b51ce2c38c55615ff7b2b1fba731ebfee5
diff --git a/internal/docker/container_helper.go b/internal/docker/container_helper.go
index cea49859..171e55e7 100644
--- a/internal/docker/container_helper.go
+++ b/internal/docker/container_helper.go
@@ -31,6 +31,9 @@ func (c containerHelper) getAliases() []string {
 }
 
 func (c containerHelper) getName() string {
+	if len(c.Names) == 0 { // Why did it happen? Every container must have a name.
+		return ""
+	}
 	return strings.TrimPrefix(c.Names[0], "/")
 }
 
diff --git a/internal/idlewatcher/watcher.go b/internal/idlewatcher/watcher.go
index 90a5030b..0be101b1 100644
--- a/internal/idlewatcher/watcher.go
+++ b/internal/idlewatcher/watcher.go
@@ -200,7 +200,7 @@ func NewWatcher(parent task.Parent, r types.Route, cfg *types.IdlewatcherConfig)
 			depCfg = new(types.IdlewatcherConfig)
 			depCfg.IdlewatcherConfigBase = cfg.IdlewatcherConfigBase
 			depCfg.IdleTimeout = neverTick // disable auto sleep for dependencies
-		} else if depCfg.IdleTimeout > 0 {
+		} else if depCfg.IdleTimeout > 0 && depCfg.IdleTimeout != neverTick {
 			depErrors.Addf("dependency %q has positive idle timeout %s", dep, depCfg.IdleTimeout)
 			continue
 		}
diff --git a/internal/route/fileserver.go b/internal/route/fileserver.go
index 80c531a6..e5b06281 100644
--- a/internal/route/fileserver.go
+++ b/internal/route/fileserver.go
@@ -2,6 +2,7 @@ package route
 
 import (
 	"net/http"
+	"os"
 	"path"
 	"path/filepath"
 
@@ -27,8 +28,25 @@ type (
 
 var _ types.FileServerRoute = (*FileServer)(nil)
 
-func handler(root string) http.Handler {
-	return http.FileServer(http.Dir(root))
+func handler(root string, spa bool, index string) http.Handler {
+	if !spa {
+		return http.FileServer(http.Dir(root))
+	}
+	indexPath := filepath.Join(root, index)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		urlPath := path.Clean(r.URL.Path)
+		if urlPath == "/" {
+			http.ServeFile(w, r, indexPath)
+			return
+		}
+		fullPath := filepath.Join(root, filepath.FromSlash(urlPath))
+		stat, err := os.Stat(fullPath)
+		if err == nil && !stat.IsDir() {
+			http.ServeFile(w, r, fullPath)
+			return
+		}
+		http.ServeFile(w, r, indexPath)
+	})
 }
 
 func NewFileServer(base *Route) (*FileServer, gperr.Error) {
@@ -39,7 +57,12 @@ func NewFileServer(base *Route) (*FileServer, gperr.Error) {
 		return nil, gperr.New("`root` must be an absolute path")
 	}
 
-	s.handler = handler(s.Root)
+	if s.Index == "" {
+		s.Index = "/index.html"
+	} else if s.Index[0] != '/' {
+		s.Index = "/" + s.Index
+	}
+	s.handler = handler(s.Root, s.SPA, s.Index)
 
 	if len(s.Middlewares) > 0 {
 		mid, err := middleware.BuildMiddlewareFromMap(s.Alias, s.Middlewares)
diff --git a/internal/route/reverse_proxy.go b/internal/route/reverse_proxy.go
index fba3bc4e..50a803e2 100755
--- a/internal/route/reverse_proxy.go
+++ b/internal/route/reverse_proxy.go
@@ -13,6 +13,7 @@ import (
 	"github.com/yusing/godoxy/internal/net/gphttp/middleware"
 	nettypes "github.com/yusing/godoxy/internal/net/types"
 	"github.com/yusing/godoxy/internal/route/routes"
+	route "github.com/yusing/godoxy/internal/route/types"
 	"github.com/yusing/godoxy/internal/types"
 	"github.com/yusing/godoxy/internal/watcher/health/monitor"
 	gperr "github.com/yusing/goutils/errs"
@@ -60,6 +61,28 @@ func NewReverseProxyRoute(base *Route) (*ReveseProxyRoute, gperr.Error) {
 	service := base.Name()
 	rp := reverseproxy.NewReverseProxy(service, &proxyURL.URL, trans)
 
+	scheme := base.Scheme
+	retried := false
+	retryLock := sync.Mutex{}
+	rp.OnSchemeMisMatch = func() (retry bool) { // switch scheme and retry
+		retryLock.Lock()
+		defer retryLock.Unlock()
+
+		if retried {
+			return false
+		}
+
+		retried = true
+
+		if scheme == route.SchemeHTTP {
+			rp.TargetURL.Scheme = "https"
+		} else {
+			rp.TargetURL.Scheme = "http"
+		}
+		rp.Info().Msgf("scheme mismatch detected, retrying with %s", rp.TargetURL.Scheme)
+		return true
+	}
+
 	if len(base.Middlewares) > 0 {
 		err := middleware.PatchReverseProxy(rp, base.Middlewares)
 		if err != nil {
diff --git a/internal/route/route.go b/internal/route/route.go
index bc97bc7d..4795f2fc 100644
--- a/internal/route/route.go
+++ b/internal/route/route.go
@@ -44,7 +44,10 @@ type (
 		Scheme route.Scheme `json:"scheme,omitempty" swaggertype:"string" enums:"http,https,tcp,udp,fileserver"`
 		Host   string       `json:"host,omitempty"`
 		Port   route.Port   `json:"port"`
-		Root   string       `json:"root,omitempty"`
+
+		Root  string `json:"root,omitempty"`
+		SPA   bool   `json:"spa,omitempty"`   // Single-page app mode: serves index for non-existent paths
+		Index string `json:"index,omitempty"` // Index file to serve for single-page app mode
 
 		route.HTTPConfig
 		PathPatterns []string                       `json:"path_patterns,omitempty" extensions:"x-nullable"`
diff --git a/internal/watcher/health/monitor/http.go b/internal/watcher/health/monitor/http.go
index 58c596b9..8f628aa3 100644
--- a/internal/watcher/health/monitor/http.go
+++ b/internal/watcher/health/monitor/http.go
@@ -40,6 +40,8 @@ func NewHTTPHealthMonitor(url *url.URL, config types.HealthCheckConfig) *HTTPHea
 	return mon
 }
 
+var userAgent = "GoDoxy/" + version.Get().String()
+
 func (mon *HTTPHealthMonitor) CheckHealth() (types.HealthCheckResult, error) {
 	req := fasthttp.AcquireRequest()
 	defer fasthttp.ReleaseRequest(req)
@@ -49,7 +51,7 @@ func (mon *HTTPHealthMonitor) CheckHealth() (types.HealthCheckResult, error) {
 
 	req.SetRequestURI(mon.url.Load().JoinPath(mon.config.Path).String())
 	req.Header.SetMethod(mon.method)
-	req.Header.Set("User-Agent", "GoDoxy/"+version.Get().String())
+	req.Header.Set("User-Agent", userAgent)
 	req.Header.Set("Accept", "text/plain,text/html,*/*;q=0.8")
 	req.Header.Set("Accept-Encoding", "identity")
 	req.Header.Set("Cache-Control", "no-cache")
diff --git a/internal/watcher/health/monitor/monitor.go b/internal/watcher/health/monitor/monitor.go
index 6afcac01..2266780e 100644
--- a/internal/watcher/health/monitor/monitor.go
+++ b/internal/watcher/health/monitor/monitor.go
@@ -74,7 +74,11 @@ func NewMonitor(r types.Route) types.HealthMonCheck {
 }
 
 func newMonitor(u *url.URL, cfg types.HealthCheckConfig, healthCheckFunc HealthCheckFunc) *monitor {
-	cfg.ApplyDefaults(config.WorkingState.Load().Value().Defaults.HealthCheck)
+	if state := config.WorkingState.Load(); state != nil {
+		cfg.ApplyDefaults(state.Value().Defaults.HealthCheck)
+	} else {
+		cfg.ApplyDefaults(types.HealthCheckConfig{}) // use defaults from constants
+	}
 	mon := &monitor{
 		config:      cfg,
 		checkHealth: healthCheckFunc,