diff --git a/event/tag/tag.go b/event/tag/tag.go
deleted file mode 100644
index b53a277..0000000
--- a/event/tag/tag.go
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package tag provides the labels used for telemetry throughout gopls.
-package tag
-
-import (
-	"github.com/qiniu/x/event/keys"
-)
-
-var (
-	// create the label keys we use
-	Method        = keys.NewString("method", "")
-	StatusCode    = keys.NewString("status.code", "")
-	StatusMessage = keys.NewString("status.message", "")
-	RPCID         = keys.NewString("id", "")
-	RPCDirection  = keys.NewString("direction", "")
-	File          = keys.NewString("file", "")
-	Directory     = keys.New("directory", "")
-	URI           = keys.New("URI", "")
-	Package       = keys.NewString("package", "") // sorted comma-separated list of Package IDs
-	PackagePath   = keys.NewString("package_path", "")
-	Query         = keys.New("query", "")
-	Snapshot      = keys.NewUInt64("snapshot", "")
-	Operation     = keys.NewString("operation", "")
-
-	Position     = keys.New("position", "")
-	Category     = keys.NewString("category", "")
-	PackageCount = keys.NewInt("packages", "")
-	Files        = keys.New("files", "")
-	Port         = keys.NewInt("port", "")
-	Type         = keys.New("type", "")
-	HoverKind    = keys.NewString("hoverkind", "")
-
-	NewServer = keys.NewString("new_server", "A new server was added")
-	EndServer = keys.NewString("end_server", "A server was shut down")
-
-	ServerID     = keys.NewString("server", "The server ID an event is related to")
-	Logfile      = keys.NewString("logfile", "")
-	DebugAddress = keys.NewString("debug_address", "")
-	GoplsPath    = keys.NewString("gopls_path", "")
-	ClientID     = keys.NewString("client_id", "")
-
-	Level = keys.NewInt("level", "The logging level")
-)
-
-var (
-	// create the stats we measure
-	Started       = keys.NewInt64("started", "Count of started RPCs.")
-	ReceivedBytes = keys.NewInt64("received_bytes", "Bytes received.")            //, unit.Bytes)
-	SentBytes     = keys.NewInt64("sent_bytes", "Bytes sent.")                    //, unit.Bytes)
-	Latency       = keys.NewFloat64("latency_ms", "Elapsed time in milliseconds") //, unit.Milliseconds)
-)
-
-const (
-	Inbound  = "in"
-	Outbound = "out"
-)