diff --git a/pkg/core/backend.go b/pkg/core/backend.go
index 9af6ca5..5415fc7 100644
--- a/pkg/core/backend.go
+++ b/pkg/core/backend.go
@@ -2,8 +2,10 @@ package core
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"time"
 
 	"code.d7z.net/d7z-project/gitea-pages/pkg/utils"
@@ -35,6 +37,9 @@ func (c *CacheBackend) Repos(owner string) (map[string]string, error) {
 	if err != nil {
 		ret, err = c.backend.Repos(owner)
 		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				_ = c.config.Put(key, "{}", c.ttl)
+			}
 			return nil, err
 		}
 		data, err := json.Marshal(data)
@@ -49,6 +54,9 @@ func (c *CacheBackend) Repos(owner string) (map[string]string, error) {
 			return nil, err
 		}
 	}
+	if len(ret) == 0 {
+		return ret, os.ErrNotExist
+	}
 	return ret, nil
 }
 
@@ -59,6 +67,9 @@ func (c *CacheBackend) Branches(owner, repo string) (map[string]string, error) {
 	if err != nil {
 		ret, err = c.backend.Branches(owner, repo)
 		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				_ = c.config.Put(key, "{}", c.ttl)
+			}
 			return nil, err
 		}
 		data, err := json.Marshal(data)
@@ -73,6 +84,9 @@ func (c *CacheBackend) Branches(owner, repo string) (map[string]string, error) {
 			return nil, err
 		}
 	}
+	if len(ret) == 0 {
+		return ret, os.ErrNotExist
+	}
 	return ret, nil
 }
 
diff --git a/pkg/core/meta.go b/pkg/core/meta.go
index a784b1e..223b3c4 100644
--- a/pkg/core/meta.go
+++ b/pkg/core/meta.go
@@ -14,83 +14,108 @@ import (
 )
 
 type ServerMeta struct {
-	client  *http.Client
-	backend Backend
-	cache   utils.Config
-	ttl     time.Duration
+	client *http.Client
+	Backend
+	cache utils.Config
+	ttl   time.Duration
+
+	locker *utils.Locker
 }
 
 type PageMeta struct {
-	CommitID         string `json:"commit_id"`     // 提交 COMMIT ID
-	IsPage           bool   `json:"is_page"`       // 是否为 Page
-	Domain           string `json:"domain"`        // 匹配的域名和路径
-	HistoryRouteMode bool   `json:"route_history"` // 路由模式
+	CommitID         string `json:"id"`  // 提交 COMMIT ID
+	IsPage           bool   `json:"pg"`  // 是否为 Page
+	Domain           string `json:"dm"`  // 匹配的域名
+	HistoryRouteMode bool   `json:"rt"`  // 路由模式
+	CustomNotFound   bool   `json:"404"` // 注册了自定义 404 页面
+
+}
+
+func (m *PageMeta) From(data string) error {
+	return json.Unmarshal([]byte(data), m)
+}
+
+func (m *PageMeta) String() string {
+	marshal, _ := json.Marshal(m)
+	return string(marshal)
 }
 
 func NewServerMeta(client *http.Client, backend Backend, config utils.Config, ttl time.Duration) *ServerMeta {
-	return &ServerMeta{client, backend, config, ttl}
+	return &ServerMeta{client, backend, config, ttl, utils.NewLocker()}
 }
 
-func (s *ServerMeta) Meta(owner, repo, branch string) (*PageMeta, error) {
+func (s *ServerMeta) GetMeta(owner, repo, branch string) (*PageMeta, error) {
 	rel := &PageMeta{
 		IsPage: false,
 	}
-	key := fmt.Sprintf("meta/%s/%s/%s", owner, repo, branch)
-	pushMeta := func() error {
-		data, err := json.Marshal(rel)
-		if err != nil {
-			return err
+	if repos, err := s.Repos(owner); err != nil {
+		return nil, err
+	} else {
+		defBranch := repos[repo]
+		if defBranch == "" {
+			return nil, os.ErrNotExist
+		}
+		if branch == "" {
+			branch = defBranch
+		}
+	}
+	if branches, err := s.Branches(owner, repo); err != nil {
+		return nil, err
+	} else {
+		rel.CommitID = branches[branch]
+		if rel.CommitID == "" {
+			return nil, os.ErrNotExist
 		}
-		return s.cache.Put(key, string(data), s.ttl)
 	}
 
+	key := fmt.Sprintf("meta/%s/%s/%s", owner, repo, branch)
 	cache, err := s.cache.Get(key)
-	if err != nil {
-		if !errors.Is(err, os.ErrNotExist) {
-			return nil, err
-		}
-	} else {
-		if err = json.Unmarshal([]byte(cache), rel); err == nil {
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+	if err == nil {
+		if err = rel.From(cache); err == nil {
+			if !rel.IsPage {
+				return nil, os.ErrNotExist
+			}
 			return rel, nil
 		}
 	}
-	repos, err := s.backend.Repos(owner)
-	if err != nil {
-		return nil, err
-	}
-	rel.CommitID = repos[repo]
-	if rel.CommitID == "" {
-		_ = pushMeta()
-		return nil, os.ErrNotExist
-	}
-	if branch != "" {
-		branches, err := s.backend.Branches(owner, repo)
-		if err != nil {
-			return nil, err
+	mux := s.locker.Open(key)
+	mux.Lock()
+	defer mux.Unlock()
+	cache, err = s.cache.Get(key)
+	if err == nil {
+		if err = rel.From(cache); err == nil {
+			if !rel.IsPage {
+				return nil, os.ErrNotExist
+			}
+			return rel, nil
 		}
-		rel.CommitID = branches[branch]
 	}
-	if rel.CommitID == "" {
-		_ = pushMeta()
+
+	if find, _ := s.FileExists(owner, repo, rel.CommitID, "index.html"); !find {
+		rel.IsPage = false
+		_ = s.cache.Put(key, rel.String(), s.ttl)
 		return nil, os.ErrNotExist
 	}
+	if find, _ := s.FileExists(owner, repo, rel.CommitID, "404.html"); !find {
+		rel.CustomNotFound = true
+	}
 	if cname, err := s.ReadString(owner, repo, rel.CommitID, "CNAME"); err != nil && !errors.Is(err, os.ErrNotExist) {
 		return nil, err
 	} else {
 		rel.Domain = strings.TrimSpace(cname)
 	}
-	if find, _ := s.FileExists(owner, repo, rel.CommitID, "index.html"); find {
-		rel.IsPage = true
-	}
-	if find, _ := s.FileExists(owner, repo, rel.CommitID, ".history-mode"); find {
+	if find, _ := s.FileExists(owner, repo, rel.CommitID, ".history"); find {
 		rel.HistoryRouteMode = true
 	}
-	_ = pushMeta()
+	_ = s.cache.Put(key, rel.String(), s.ttl)
 	return rel, nil
 }
 
 func (s *ServerMeta) ReadString(owner, repo, branch, path string) (string, error) {
-	resp, err := s.backend.Open(s.client, owner, repo, branch, path, nil)
+	resp, err := s.Open(s.client, owner, repo, branch, path, nil)
 	if err != nil {
 		return "", err
 	}
@@ -106,7 +131,7 @@ func (s *ServerMeta) ReadString(owner, repo, branch, path string) (string, error
 }
 
 func (s *ServerMeta) FileExists(owner, repo, branch, path string) (bool, error) {
-	resp, err := s.backend.Open(s.client, owner, repo, branch, path, nil)
+	resp, err := s.Open(s.client, owner, repo, branch, path, nil)
 	if err != nil {
 		return false, err
 	}
diff --git a/pkg/core/page.go b/pkg/core/page.go
new file mode 100644
index 0000000..f692a5e
--- /dev/null
+++ b/pkg/core/page.go
@@ -0,0 +1,9 @@
+package core
+
+type PageContent struct {
+	meta PageMeta
+}
+
+func (p *PageContent) GetMeta(domain, path string) (*PageMeta, error) {
+
+}
diff --git a/pkg/server.go b/pkg/server.go
index 18f220e..733a929 100644
--- a/pkg/server.go
+++ b/pkg/server.go
@@ -15,6 +15,8 @@ type ServerOptions struct {
 	Cache  utils.Cache
 
 	MaxCacheSize int
+
+	HttpClient *http.Client
 }
 
 func DefaultOptions(domain string) ServerOptions {
@@ -24,22 +26,25 @@ func DefaultOptions(domain string) ServerOptions {
 		Config:       configMemory,
 		Cache:        utils.NewCacheMemory(1024*1024*10, int(memory.FreeMemory()/3*2)),
 		MaxCacheSize: 1024 * 1024 * 10,
+		HttpClient:   http.DefaultClient,
 	}
 }
 
 type Server struct {
-	backend core.Backend
+	meta    *core.ServerMeta
 	options *ServerOptions
 }
 
 func NewPageServer(backend core.Backend, options ServerOptions) *Server {
+	backend = core.NewCacheBackend(backend, options.Config, time.Minute)
 	return &Server{
-		backend: core.NewCacheBackend(backend, options.Config, time.Minute),
+		meta:    core.NewServerMeta(options.HttpClient, backend, options.Config, time.Minute),
 		options: &options,
 	}
 }
 
 func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+
 }
 
 func (s *Server) Close() error {
diff --git a/pkg/utils/locker.go b/pkg/utils/locker.go
new file mode 100644
index 0000000..728953b
--- /dev/null
+++ b/pkg/utils/locker.go
@@ -0,0 +1,17 @@
+package utils
+
+import "sync"
+
+type Locker struct {
+	sy sync.Map
+}
+
+func NewLocker() *Locker {
+	return &Locker{
+		sy: sync.Map{},
+	}
+}
+func (l *Locker) Open(key string) *sync.Mutex {
+	actual, _ := l.sy.LoadOrStore(key, &sync.Mutex{})
+	return actual.(*sync.Mutex)
+}