diff --git a/go/vendor/google.golang.org/grpc/peer/peer.go b/go/vendor/google.golang.org/grpc/peer/peer.go
new file mode 100644
index 0000000..317b8b9
--- /dev/null
+++ b/go/vendor/google.golang.org/grpc/peer/peer.go
@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package peer defines various peer information associated with RPCs and
+// corresponding utils.
+package peer
+
+import (
+	"net"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/credentials"
+)
+
+// Peer contains the information of the peer for an RPC, such as the address
+// and authentication information.
+type Peer struct {
+	// Addr is the peer address.
+	Addr net.Addr
+	// AuthInfo is the authentication information of the transport.
+	// It is nil if there is no transport security being used.
+	AuthInfo credentials.AuthInfo
+}
+
+type peerKey struct{}
+
+// NewContext creates a new context with peer information attached.
+func NewContext(ctx context.Context, p *Peer) context.Context {
+	return context.WithValue(ctx, peerKey{}, p)
+}
+
+// FromContext returns the peer information in ctx if it exists.
+func FromContext(ctx context.Context) (p *Peer, ok bool) {
+	p, ok = ctx.Value(peerKey{}).(*Peer)
+	return
+}