diff --git a/etcdmain/config.go b/etcdmain/config.go
index 117ba4a9bfd6..30d3c15f556b 100644
--- a/etcdmain/config.go
+++ b/etcdmain/config.go
@@ -115,6 +115,8 @@ type config struct {
 
 	printVersion bool
 
+	v3demo bool
+
 	ignored []string
 }
 
@@ -208,6 +210,9 @@ func NewConfig() *config {
 	// version
 	fs.BoolVar(&cfg.printVersion, "version", false, "Print the version and exit")
 
+	// demo flag
+	fs.BoolVar(&cfg.v3demo, "v3demo", false, "Enable v3 demo")
+
 	// backwards-compatibility with v0.4.6
 	fs.Var(&flags.IPAddressPort{}, "addr", "DEPRECATED: Use -advertise-client-urls instead.")
 	fs.Var(&flags.IPAddressPort{}, "bind-addr", "DEPRECATED: Use -listen-client-urls instead.")
diff --git a/etcdmain/etcd.go b/etcdmain/etcd.go
index 3c925bf64cbb..77619237d41f 100644
--- a/etcdmain/etcd.go
+++ b/etcdmain/etcd.go
@@ -31,9 +31,12 @@ import (
 	systemdutil "github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/go-systemd/util"
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/pkg/capnslog"
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/prometheus/client_golang/prometheus"
+	"github.com/coreos/etcd/Godeps/_workspace/src/google.golang.org/grpc"
 	"github.com/coreos/etcd/discovery"
 	"github.com/coreos/etcd/etcdserver"
+	"github.com/coreos/etcd/etcdserver/api/v3rpc"
 	"github.com/coreos/etcd/etcdserver/etcdhttp"
+	"github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/pkg/cors"
 	"github.com/coreos/etcd/pkg/fileutil"
 	"github.com/coreos/etcd/pkg/osutil"
@@ -233,6 +236,15 @@ func startEtcd(cfg *config) (<-chan struct{}, error) {
 		clns = append(clns, l)
 	}
 
+	var v3l net.Listener
+	if cfg.v3demo {
+		v3l, err = net.Listen("tcp", "127.0.0.1:12379")
+		if err != nil {
+			plog.Fatal(err)
+		}
+		plog.Infof("listening for client rpc on 127.0.0.1:12379")
+	}
+
 	srvcfg := &etcdserver.ServerConfig{
 		Name:                cfg.name,
 		ClientURLs:          cfg.acurls,
@@ -250,6 +262,7 @@ func startEtcd(cfg *config) (<-chan struct{}, error) {
 		Transport:           pt,
 		TickMs:              cfg.TickMs,
 		ElectionTicks:       cfg.electionTicks(),
+		V3demo:              cfg.v3demo,
 	}
 	var s *etcdserver.EtcdServer
 	s, err = etcdserver.NewServer(srvcfg)
@@ -281,6 +294,14 @@ func startEtcd(cfg *config) (<-chan struct{}, error) {
 			plog.Fatal(serveHTTP(l, ch, 0))
 		}(l)
 	}
+
+	if cfg.v3demo {
+		// set up v3 demo rpc
+		grpcServer := grpc.NewServer()
+		etcdserverpb.RegisterEtcdServer(grpcServer, v3rpc.New(s))
+		go plog.Fatal(grpcServer.Serve(v3l))
+	}
+
 	return s.StopNotify(), nil
 }
 
diff --git a/etcdserver/api/v3rpc/key.go b/etcdserver/api/v3rpc/key.go
new file mode 100644
index 000000000000..da029fac721d
--- /dev/null
+++ b/etcdserver/api/v3rpc/key.go
@@ -0,0 +1,54 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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 v3rpc
+
+import (
+	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
+	"github.com/coreos/etcd/etcdserver"
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+)
+
+type handler struct {
+	server etcdserver.Server
+}
+
+func New(s etcdserver.Server) pb.EtcdServer {
+	return &handler{s}
+}
+
+func (h *handler) Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	resp := h.server.V3DemoDo(ctx, pb.InternalRaftRequest{Range: r})
+	return resp.(*pb.RangeResponse), nil
+}
+
+func (h *handler) Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error) {
+	resp := h.server.V3DemoDo(ctx, pb.InternalRaftRequest{Put: r})
+	return resp.(*pb.PutResponse), nil
+}
+
+func (h *handler) DeleteRange(ctx context.Context, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	panic("not implemented")
+	return nil, nil
+}
+
+func (h *handler) Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	panic("not implemented")
+	return nil, nil
+}
+
+func (h *handler) Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error) {
+	panic("not implemented")
+	return nil, nil
+}
diff --git a/etcdserver/config.go b/etcdserver/config.go
index 9b6132670ecb..b19eae375c2e 100644
--- a/etcdserver/config.go
+++ b/etcdserver/config.go
@@ -43,6 +43,8 @@ type ServerConfig struct {
 
 	TickMs        uint
 	ElectionTicks int
+
+	V3demo bool
 }
 
 // VerifyBootstrapConfig sanity-checks the initial config for bootstrap case
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 330029bdad06..fbfc20b9876a 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"math/rand"
 	"net/http"
+	"os"
 	"path"
 	"regexp"
 	"sync/atomic"
@@ -27,6 +28,7 @@ import (
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/go-semver/semver"
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/pkg/capnslog"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/gogo/protobuf/proto" // owner can make/remove files inside the directory
 	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
 	"github.com/coreos/etcd/discovery"
 	"github.com/coreos/etcd/etcdserver/etcdhttp/httptypes"
@@ -43,13 +45,13 @@ import (
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/rafthttp"
 	"github.com/coreos/etcd/snap"
+	dstorage "github.com/coreos/etcd/storage"
 	"github.com/coreos/etcd/store"
 	"github.com/coreos/etcd/version"
 	"github.com/coreos/etcd/wal"
 )
 
 const (
-	// owner can make/remove files inside the directory
 	privateDirMode = 0700
 
 	defaultSyncTimeout = time.Second
@@ -106,6 +108,7 @@ type Server interface {
 	Leader() types.ID
 	// Do takes a request and attempts to fulfill it, returning a Response.
 	Do(ctx context.Context, r pb.Request) (Response, error)
+	V3DemoDo(ctx context.Context, r pb.InternalRaftRequest) proto.Message
 	// Process takes a raft message and applies it to the server's raft state
 	// machine, respecting any timeout of the given context.
 	Process(ctx context.Context, m raftpb.Message) error
@@ -156,6 +159,7 @@ type EtcdServer struct {
 	cluster *cluster
 
 	store store.Store
+	kv    dstorage.KV
 
 	stats  *stats.ServerStats
 	lstats *stats.LeaderStats
@@ -313,6 +317,13 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		forceVersionC: make(chan struct{}),
 	}
 
+	if cfg.V3demo {
+		srv.kv = dstorage.New(path.Join(cfg.DataDir, "member", "v3demo"))
+	} else {
+		// we do not care about the error of the removal
+		os.RemoveAll(path.Join(cfg.DataDir, "member", "v3demo"))
+	}
+
 	// TODO: move transport initialization near the definition of remote
 	tr := rafthttp.NewTransporter(cfg.Transport, id, cl.ID(), srv, srv.errorc, sstats, lstats)
 	// add all remotes into transport
diff --git a/etcdserver/v3demo_server.go b/etcdserver/v3demo_server.go
new file mode 100644
index 000000000000..0f0fa8a2acce
--- /dev/null
+++ b/etcdserver/v3demo_server.go
@@ -0,0 +1,53 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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 etcdserver
+
+import (
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/gogo/protobuf/proto"
+	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+)
+
+func (s *EtcdServer) V3DemoDo(ctx context.Context, r pb.InternalRaftRequest) proto.Message {
+	switch {
+	case r.Range != nil:
+		rr := r.Range
+		resp := &pb.RangeResponse{}
+		resp.Header = &pb.ResponseHeader{}
+		kvs, rev, err := s.kv.Range(rr.Key, rr.RangeEnd, rr.Limit, 0)
+		if err != nil {
+			panic("not handled error")
+		}
+
+		resp.Header.Index = rev
+		for i := range kvs {
+			resp.Kvs = append(resp.Kvs, &kvs[i])
+		}
+		return resp
+	case r.Put != nil:
+		rp := r.Put
+		resp := &pb.PutResponse{}
+		resp.Header = &pb.ResponseHeader{}
+		rev := s.kv.Put(rp.Key, rp.Value)
+		resp.Header.Index = rev
+		return resp
+	case r.DeleteRange != nil:
+	case r.Txn != nil:
+		panic("not implemented")
+	default:
+		panic("not implemented")
+	}
+	return nil
+}