diff --git a/internal/api/handlers/management/auth_files.go b/internal/api/handlers/management/auth_files.go
index e2ff23f1..fd45ae19 100644
--- a/internal/api/handlers/management/auth_files.go
+++ b/internal/api/handlers/management/auth_files.go
@@ -864,11 +864,17 @@ func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (s
 	if store == nil {
 		return "", fmt.Errorf("token store unavailable")
 	}
+	if h.postAuthHook != nil {
+		if err := h.postAuthHook(ctx, record); err != nil {
+			return "", fmt.Errorf("post-auth hook failed: %w", err)
+		}
+	}
 	return store.Save(ctx, record)
 }
 
 func (h *Handler) RequestAnthropicToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing Claude authentication...")
 
@@ -1013,6 +1019,7 @@ func (h *Handler) RequestAnthropicToken(c *gin.Context) {
 
 func (h *Handler) RequestGeminiCLIToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 	proxyHTTPClient := util.SetProxy(&h.cfg.SDKConfig, &http.Client{})
 	ctx = context.WithValue(ctx, oauth2.HTTPClient, proxyHTTPClient)
 
@@ -1247,6 +1254,7 @@ func (h *Handler) RequestGeminiCLIToken(c *gin.Context) {
 
 func (h *Handler) RequestCodexToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing Codex authentication...")
 
@@ -1392,6 +1400,7 @@ func (h *Handler) RequestCodexToken(c *gin.Context) {
 
 func (h *Handler) RequestAntigravityToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing Antigravity authentication...")
 
@@ -1556,6 +1565,7 @@ func (h *Handler) RequestAntigravityToken(c *gin.Context) {
 
 func (h *Handler) RequestQwenToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing Qwen authentication...")
 
@@ -1611,6 +1621,7 @@ func (h *Handler) RequestQwenToken(c *gin.Context) {
 
 func (h *Handler) RequestKimiToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing Kimi authentication...")
 
@@ -1687,6 +1698,7 @@ func (h *Handler) RequestKimiToken(c *gin.Context) {
 
 func (h *Handler) RequestIFlowToken(c *gin.Context) {
 	ctx := context.Background()
+	ctx = PopulateAuthContext(ctx, c)
 
 	fmt.Println("Initializing iFlow authentication...")
 
@@ -2266,3 +2278,28 @@ func (h *Handler) GetAuthStatus(c *gin.Context) {
 	}
 	c.JSON(http.StatusOK, gin.H{"status": "wait"})
 }
+
+// PopulateAuthContext extracts request info and adds it to the context
+func PopulateAuthContext(ctx context.Context, c *gin.Context) context.Context {
+	info := &coreauth.RequestInfo{
+		Query:   make(map[string]string),
+		Headers: make(map[string]string),
+	}
+
+	// Capture all query parameters
+	for k, v := range c.Request.URL.Query() {
+		if len(v) > 0 {
+			info.Query[k] = v[0]
+		}
+	}
+
+	// Capture specific headers relevant for logging/auditing
+	headers := []string{"User-Agent", "X-Forwarded-For", "X-Real-IP", "Referer"}
+	for _, h := range headers {
+		if val := c.GetHeader(h); val != "" {
+			info.Headers[h] = val
+		}
+	}
+
+	return context.WithValue(ctx, "request_info", info)
+}
diff --git a/internal/api/handlers/management/handler.go b/internal/api/handlers/management/handler.go
index 613c9841..45786b9d 100644
--- a/internal/api/handlers/management/handler.go
+++ b/internal/api/handlers/management/handler.go
@@ -47,6 +47,7 @@ type Handler struct {
 	allowRemoteOverride bool
 	envSecret           string
 	logDir              string
+	postAuthHook        coreauth.PostAuthHook
 }
 
 // NewHandler creates a new management handler instance.
@@ -128,6 +129,11 @@ func (h *Handler) SetLogDirectory(dir string) {
 	h.logDir = dir
 }
 
+// SetPostAuthHook registers a hook to be called after auth record creation but before persistence.
+func (h *Handler) SetPostAuthHook(hook coreauth.PostAuthHook) {
+	h.postAuthHook = hook
+}
+
 // Middleware enforces access control for management endpoints.
 // All requests (local and remote) require a valid management key.
 // Additionally, remote access requires allow-remote-management=true.
diff --git a/internal/api/server.go b/internal/api/server.go
index 4cbcbba2..52e7dd29 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -51,6 +51,7 @@ type serverOptionConfig struct {
 	keepAliveEnabled     bool
 	keepAliveTimeout     time.Duration
 	keepAliveOnTimeout   func()
+	postAuthHook         auth.PostAuthHook
 }
 
 // ServerOption customises HTTP server construction.
@@ -111,6 +112,13 @@ func WithRequestLoggerFactory(factory func(*config.Config, string) logging.Reque
 	}
 }
 
+// WithPostAuthHook registers a hook to be called after auth record creation.
+func WithPostAuthHook(hook auth.PostAuthHook) ServerOption {
+	return func(cfg *serverOptionConfig) {
+		cfg.postAuthHook = hook
+	}
+}
+
 // Server represents the main API server.
 // It encapsulates the Gin engine, HTTP server, handlers, and configuration.
 type Server struct {
@@ -262,6 +270,9 @@ func NewServer(cfg *config.Config, authManager *auth.Manager, accessManager *sdk
 	}
 	logDir := logging.ResolveLogDirectory(cfg)
 	s.mgmt.SetLogDirectory(logDir)
+	if optionState.postAuthHook != nil {
+		s.mgmt.SetPostAuthHook(optionState.postAuthHook)
+	}
 	s.localPassword = optionState.localPassword
 
 	// Setup routes
diff --git a/internal/auth/gemini/gemini_token.go b/internal/auth/gemini/gemini_token.go
index 0ec7da17..24828076 100644
--- a/internal/auth/gemini/gemini_token.go
+++ b/internal/auth/gemini/gemini_token.go
@@ -35,11 +35,21 @@ type GeminiTokenStorage struct {
 
 	// Type indicates the authentication provider type, always "gemini" for this storage.
 	Type string `json:"type"`
+
+	// Metadata holds arbitrary key-value pairs injected via hooks.
+	// It is not exported to JSON directly to allow flattening during serialization.
+	Metadata map[string]any `json:"-"`
+}
+
+// SetMetadata allows external callers to inject metadata into the storage before saving.
+func (ts *GeminiTokenStorage) SetMetadata(meta map[string]any) {
+	ts.Metadata = meta
 }
 
 // SaveTokenToFile serializes the Gemini token storage to a JSON file.
 // This method creates the necessary directory structure and writes the token
 // data in JSON format to the specified file path for persistent storage.
+// It merges any injected metadata into the top-level JSON object.
 //
 // Parameters:
 //   - authFilePath: The full path where the token file should be saved
@@ -63,7 +73,24 @@ func (ts *GeminiTokenStorage) SaveTokenToFile(authFilePath string) error {
 		}
 	}()
 
-	if err = json.NewEncoder(f).Encode(ts); err != nil {
+	// Convert struct to map for merging
+	data := make(map[string]any)
+	temp, errJson := json.Marshal(ts)
+	if errJson != nil {
+		return fmt.Errorf("failed to marshal struct: %w", errJson)
+	}
+	if errUnmarshal := json.Unmarshal(temp, &data); errUnmarshal != nil {
+		return fmt.Errorf("failed to unmarshal struct map: %w", errUnmarshal)
+	}
+
+	// Merge extra metadata
+	if ts.Metadata != nil {
+		for k, v := range ts.Metadata {
+			data[k] = v
+		}
+	}
+
+	if err = json.NewEncoder(f).Encode(data); err != nil {
 		return fmt.Errorf("failed to write token to file: %w", err)
 	}
 	return nil
diff --git a/sdk/auth/filestore.go b/sdk/auth/filestore.go
index 0bb7ff7d..a68d3cd2 100644
--- a/sdk/auth/filestore.go
+++ b/sdk/auth/filestore.go
@@ -62,8 +62,16 @@ func (s *FileTokenStore) Save(ctx context.Context, auth *cliproxyauth.Auth) (str
 		return "", fmt.Errorf("auth filestore: create dir failed: %w", err)
 	}
 
+	// metadataSetter is a private interface for TokenStorage implementations that support metadata injection.
+	type metadataSetter interface {
+		SetMetadata(map[string]any)
+	}
+
 	switch {
 	case auth.Storage != nil:
+		if setter, ok := auth.Storage.(metadataSetter); ok {
+			setter.SetMetadata(auth.Metadata)
+		}
 		if err = auth.Storage.SaveTokenToFile(path); err != nil {
 			return "", err
 		}
diff --git a/sdk/cliproxy/auth/types.go b/sdk/cliproxy/auth/types.go
index b2bbe0a2..e1ba6bb5 100644
--- a/sdk/cliproxy/auth/types.go
+++ b/sdk/cliproxy/auth/types.go
@@ -1,6 +1,7 @@
 package auth
 
 import (
+	"context"
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
@@ -12,6 +13,18 @@ import (
 	baseauth "github.com/router-for-me/CLIProxyAPI/v6/internal/auth"
 )
 
+// PostAuthHook defines a function that is called after an Auth record is created
+// but before it is persisted to storage. This allows for modification of the
+// Auth record (e.g., injecting metadata) based on external context.
+type PostAuthHook func(context.Context, *Auth) error
+
+// RequestInfo holds information extracted from the HTTP request.
+// It is injected into the context passed to PostAuthHook.
+type RequestInfo struct {
+	Query   map[string]string
+	Headers map[string]string
+}
+
 // Auth encapsulates the runtime state and metadata associated with a single credential.
 type Auth struct {
 	// ID uniquely identifies the auth record across restarts.
diff --git a/sdk/cliproxy/builder.go b/sdk/cliproxy/builder.go
index 60ca07f5..0e6d1421 100644
--- a/sdk/cliproxy/builder.go
+++ b/sdk/cliproxy/builder.go
@@ -153,6 +153,16 @@ func (b *Builder) WithLocalManagementPassword(password string) *Builder {
 	return b
 }
 
+// WithPostAuthHook registers a hook to be called after an Auth record is created
+// but before it is persisted to storage.
+func (b *Builder) WithPostAuthHook(hook coreauth.PostAuthHook) *Builder {
+	if hook == nil {
+		return b
+	}
+	b.serverOptions = append(b.serverOptions, api.WithPostAuthHook(hook))
+	return b
+}
+
 // Build validates inputs, applies defaults, and returns a ready-to-run service.
 func (b *Builder) Build() (*Service, error) {
 	if b.cfg == nil {