diff --git a/ydb/tools/tsserver/defs.h b/ydb/tools/tsserver/defs.h
new file mode 100644
index 000000000000..e9dfa8a60a1c
--- /dev/null
+++ b/ydb/tools/tsserver/defs.h
@@ -0,0 +1,4 @@
+#pragma once
+
+#include <ydb/core/test_tablet/processor.h>
+#include <ydb/library/actors/interconnect/interconnect_stream.h>
diff --git a/ydb/tools/tsserver/main.cpp b/ydb/tools/tsserver/main.cpp
new file mode 100644
index 000000000000..925e3380c495
--- /dev/null
+++ b/ydb/tools/tsserver/main.cpp
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <sys/epoll.h>
+#include <ydb/core/protos/test_shard.pb.h>
+#include "socket_context.h"
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) {
+        printf("Usage: %s <port>\n", argv[0]);
+        return 1;
+    }
+
+    auto server = NInterconnect::TStreamSocket::Make(AF_INET6);
+    Y_ABORT_UNLESS(*server != -1, "failed to create server socket");
+    SetNonBlock(*server);
+    SetSockOpt(*server, SOL_SOCKET, SO_REUSEADDR, 1);
+    SetSockOpt(*server, SOL_SOCKET, SO_REUSEPORT, 1);
+
+    int res = server->Bind(NInterconnect::TAddress("::", atoi(argv[1])));
+    Y_ABORT_UNLESS(!res, "failed to bind server socket: %s", strerror(-res));
+    res = server->Listen(10);
+    Y_ABORT_UNLESS(!res, "failed to listen on server socket: %s", strerror(-res));
+
+    int epfd = epoll_create(1);
+    if (epfd == -1) {
+        Y_ABORT("failed to create epoll: %s", strerror(errno));
+    }
+
+    epoll_event e;
+    e.events = EPOLLIN;
+    e.data.u64 = 0;
+    if (epoll_ctl(epfd, EPOLL_CTL_ADD, *server, &e) == -1) {
+        Y_ABORT("failed to add listening socket to epoll: %s", strerror(errno));
+    }
+
+    std::unordered_map<ui64, TSocketContext> Clients;
+    ui64 LastClientId = 0;
+
+    TProcessor processor;
+
+    for (;;) {
+        static constexpr size_t N = 64;
+        epoll_event events[N];
+        int res = epoll_wait(epfd, events, N, -1);
+        if (res == -1) {
+            if (errno == EINTR) {
+                continue;
+            } else {
+                Y_ABORT("epoll_wait failed: %s", strerror(errno));
+            }
+        }
+        for (int i = 0; i < res; ++i) {
+            epoll_event& e = events[i];
+            if (!e.data.u64) {
+                NInterconnect::TAddress addr;
+                int fd = server->Accept(addr);
+                Y_ABORT_UNLESS(fd >= 0, "failed to accept client socket: %s", strerror(-fd));
+                auto client = MakeIntrusive<NInterconnect::TStreamSocket>(fd);
+                SetNonBlock(*client);
+                SetNoDelay(*client, true);
+                const ui64 clientId = ++LastClientId;
+                auto&& [it, inserted] = Clients.try_emplace(clientId, clientId, epfd, client, processor);
+                Y_ABORT_UNLESS(inserted);
+            } else if (auto it = Clients.find(e.data.u64); it != Clients.end()) {
+                try {
+                    if (e.events & EPOLLIN) {
+                        it->second.Read();
+                    }
+                    if (e.events & EPOLLOUT) {
+                        it->second.Write();
+                    }
+                    it->second.UpdateEpoll();
+                } catch (const TExError&) {
+                    Clients.erase(it);
+                }
+            }
+        }
+    }
+
+    close(epfd);
+
+    return 0;
+}
diff --git a/ydb/tools/tsserver/socket_context.h b/ydb/tools/tsserver/socket_context.h
new file mode 100644
index 000000000000..e2c04b8d4da8
--- /dev/null
+++ b/ydb/tools/tsserver/socket_context.h
@@ -0,0 +1,161 @@
+#pragma once
+
+#include "defs.h"
+#include "types.h"
+
+using TProcessor = NKikimr::NTestShard::TProcessor;
+
+class TSocketContext {
+    const ui64 ClientId;
+    const int EpollFd;
+    TIntrusivePtr<NInterconnect::TStreamSocket> Socket;
+    TProcessor& Processor;
+
+    enum class EReadStep {
+        LEN,
+        DATA,
+    } ReadStep = EReadStep::LEN;
+    TString ReadBuffer = TString::Uninitialized(sizeof(ui32));
+    char *ReadBegin = ReadBuffer.Detach(), *ReadEnd = ReadBegin + ReadBuffer.size();
+
+    std::deque<TString> OutQ;
+    size_t WriteOffset = 0;
+
+    std::optional<ui32> StoredEvents;
+    ui32 Events = 0;
+
+public:
+    TSocketContext(ui64 clientId, int epollFd, TIntrusivePtr<NInterconnect::TStreamSocket> socket, TProcessor& processor)
+        : ClientId(clientId)
+        , EpollFd(epollFd)
+        , Socket(std::move(socket))
+        , Processor(processor)
+    {
+        printf("[%" PRIu64 "] created\n", ClientId);
+        Read();
+        Write();
+        UpdateEpoll();
+    }
+
+    ~TSocketContext() {
+        if (StoredEvents) {
+            Epoll(EPOLL_CTL_DEL, 0);
+        }
+    }
+
+    void Epoll(int op, ui32 events) {
+        epoll_event e;
+        e.events = events;
+        e.data.u64 = ClientId;
+        if (epoll_ctl(EpollFd, op, *Socket, &e) == -1) {
+            Y_ABORT("epoll_ctl failed: %s", strerror(errno));
+        }
+    }
+
+    void UpdateEpoll() {
+        std::optional<int> mode = !StoredEvents ? std::make_optional(EPOLL_CTL_ADD) :
+            *StoredEvents != Events ? std::make_optional(EPOLL_CTL_MOD) : std::nullopt;
+        if (mode) {
+            Epoll(*mode, Events);
+        }
+        StoredEvents = Events;
+    }
+
+    void Read() {
+        for (;;) {
+            ssize_t n = Socket->Recv(ReadBegin, ReadEnd - ReadBegin);
+            if (n > 0) {
+                ReadBegin += n;
+                if (ReadBegin == ReadEnd) {
+                    switch (ReadStep) {
+                        case EReadStep::LEN: {
+                            ui32 n;
+                            Y_ABORT_UNLESS(ReadBuffer.size() == sizeof(n));
+                            memcpy(&n, ReadBuffer.data(), ReadBuffer.size()); // strict aliasing
+                            Y_ABORT_UNLESS(n <= 64 * 1024 * 1024);
+                            ReadBuffer = TString::Uninitialized(n);
+                            ReadStep = EReadStep::DATA;
+                            break;
+                        }
+
+                        case EReadStep::DATA:
+                            ProcessReadBuffer();
+                            ReadBuffer = TString::Uninitialized(sizeof(ui32));
+                            ReadStep = EReadStep::LEN;
+                            break;
+                    }
+                    ReadBegin = ReadBuffer.Detach();
+                    ReadEnd = ReadBegin + ReadBuffer.size();
+                }
+            } else if (-n == EAGAIN || -n == EWOULDBLOCK) {
+                Events |= EPOLLIN;
+                break;
+            } else if (-n == EINTR) {
+                continue;
+            } else {
+                printf("[%" PRIu64 "] failed to receive data: %s\n", ClientId, strerror(-n));
+                throw TExError();
+            }
+        }
+    }
+
+    void ProcessReadBuffer() {
+        ::NTestShard::TStateServer::TRequest request;
+        if (!request.ParseFromString(ReadBuffer)) {
+            throw TExError();
+        }
+        auto send = [this](const auto& proto) {
+            TString buffer;
+            const bool success = proto.SerializeToString(&buffer);
+            Y_ABORT_UNLESS(success);
+            Y_ABORT_UNLESS(buffer.size() <= 64 * 1024 * 1024);
+            ui32 len = buffer.size();
+            TString w = TString::Uninitialized(sizeof(ui32) + len);
+            char *p = w.Detach();
+            memcpy(p, &len, sizeof(len));
+            memcpy(p + sizeof(len), buffer.data(), buffer.size());
+            OutQ.push_back(std::move(w));
+            Write();
+        };
+        switch (request.GetCommandCase()) {
+            case ::NTestShard::TStateServer::TRequest::kWrite:
+                send(Processor.Execute(request.GetWrite()));
+                break;
+
+            case ::NTestShard::TStateServer::TRequest::kRead:
+                send(Processor.Execute(request.GetRead()));
+                break;
+
+            case ::NTestShard::TStateServer::TRequest::kTabletInfo:
+            case ::NTestShard::TStateServer::TRequest::COMMAND_NOT_SET:
+                printf("[%" PRIu64 "] incorrect request received\n", ClientId);
+                throw TExError();
+        }
+    }
+
+    void Write() {
+        while (!OutQ.empty()) {
+            auto& buffer = OutQ.front();
+            if (WriteOffset == buffer.size()) {
+                OutQ.pop_front();
+                WriteOffset = 0;
+                continue;
+            }
+            ssize_t n = Socket->Send(buffer.data() + WriteOffset, buffer.size() - WriteOffset);
+            if (n > 0) {
+                WriteOffset += n;
+            } else if (-n == EWOULDBLOCK || -n == EAGAIN) {
+                break;
+            } else if (-n == EINTR) {
+                continue;
+            } else {
+                printf("[%" PRIu64 "] failed to send data: %s\n", ClientId, strerror(-n));
+            }
+        }
+        if (OutQ.empty()) {
+            Events &= ~EPOLLOUT;
+        } else {
+            Events |= EPOLLOUT;
+        }
+    }
+};
diff --git a/ydb/tools/tsserver/types.h b/ydb/tools/tsserver/types.h
new file mode 100644
index 000000000000..444e26986082
--- /dev/null
+++ b/ydb/tools/tsserver/types.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#include "defs.h"
+
+struct TExError : std::exception {};
diff --git a/ydb/tools/tsserver/ya.make b/ydb/tools/tsserver/ya.make
new file mode 100644
index 000000000000..a43950c5bf33
--- /dev/null
+++ b/ydb/tools/tsserver/ya.make
@@ -0,0 +1,14 @@
+PROGRAM()
+
+OWNER(alexvru)
+
+SRCS(
+    main.cpp
+)
+
+PEERDIR(
+    ydb/library/actors/interconnect
+    ydb/core/protos
+)
+
+END()
diff --git a/ydb/tools/tstool/testshard.txt b/ydb/tools/tstool/testshard.txt
new file mode 100644
index 000000000000..018307bd55da
--- /dev/null
+++ b/ydb/tools/tstool/testshard.txt
@@ -0,0 +1,7 @@
+StorageServerPort: 35000
+MaxDataBytes: 1500000000
+MinDataBytes: 1000000000
+MaxInFlight: 5
+Sizes { Weight: 1 Min: 1 Max: 1024 Inline: true }
+Sizes { Weight: 3 Min: 10000 Max: 1000000 }
+Sizes { Weight: 7 Min: 2357120 Max: 8388608 }
diff --git a/ydb/tools/tstool/tstool.py b/ydb/tools/tstool/tstool.py
new file mode 100644
index 000000000000..8c6568d59eae
--- /dev/null
+++ b/ydb/tools/tstool/tstool.py
@@ -0,0 +1,102 @@
+from argparse import ArgumentParser, FileType
+from ydb.core.protos.grpc_pb2_grpc import TGRpcServerStub
+from ydb.core.protos.msgbus_pb2 import THiveCreateTablet, TTestShardControlRequest
+from ydb.core.protos.tablet_pb2 import TTabletTypes
+from ydb.core.protos.base_pb2 import EReplyStatus
+from google.protobuf import text_format
+import grpc
+import socket
+import sys
+import time
+import multiprocessing
+import random
+
+grpc_host = None
+grpc_port = None
+domain_uid = None
+default_tsserver_port = 35000
+
+
+def invoke_grpc(func, *params):
+    with grpc.insecure_channel('%s:%d' % (grpc_host, grpc_port), []) as channel:
+        stub = TGRpcServerStub(channel)
+        return getattr(stub, func)(*params)
+
+
+def create_tablet(owner_idx, channels, count):
+    request = THiveCreateTablet(DomainUid=domain_uid)
+    for i in range(count):
+        cmd = request.CmdCreateTablet.add(OwnerId=0, OwnerIdx=owner_idx + i, TabletType=TTabletTypes.TestShard, ChannelsProfile=0)
+        for channel in channels:
+            cmd.BindedChannels.add(StoragePoolName=channel, PhysicalGroupsOnly=False)
+
+    for _ in range(10):
+        res = invoke_grpc('HiveCreateTablet', request)
+        if res.Status == 1:
+            assert all(r.Status in [EReplyStatus.OK, EReplyStatus.ALREADY] for r in res.CreateTabletResult)
+            return [r.TabletId for r in res.CreateTabletResult]
+        else:
+            print(res, file=sys.stderr)
+            time.sleep(3)
+
+    assert False
+
+
+def init_tablet(args):
+    tablet_id, cmd = args
+    request = TTestShardControlRequest(TabletId=tablet_id, Initialize=cmd)
+
+    for _ in range(100):
+        res = invoke_grpc('TestShardControl', request)
+        if res.Status == 1:
+            return None
+        else:
+            time.sleep(random.uniform(1.0, 2.0))
+
+    return str(tablet_id) + ': ' + str(res)
+
+
+def main():
+    parser = ArgumentParser(description='YDB TestShard control tool')
+    parser.add_argument('--grpc-host', type=str, required=True, help='gRPC endpoint hostname')
+    parser.add_argument('--grpc-port', type=int, default=2135, help='gRPC endpoint port')
+    parser.add_argument('--domain-uid', type=int, default=1, help='domain UID')
+    parser.add_argument('--owner-idx', type=int, required=True, help='unique instance id for tablet creation')
+    parser.add_argument('--channels', type=str, nargs='+', required=True, help='channel storage pool names')
+    parser.add_argument('--count', type=int, default=1, help='create desired amount of tablets at once')
+
+    subparsers = parser.add_subparsers(help='Action', dest='action', required=True)
+
+    p = subparsers.add_parser('initialize', help='initialize test shard state')
+    p.add_argument('--proto-file', type=FileType(), required=True, help='path to protobuf containing TCmdInitialize')
+    p.add_argument('--tsserver', type=str, help='FQDN:port pair for tsserver')
+
+    args = parser.parse_args()
+
+    global grpc_host, grpc_port, domain_uid
+    grpc_host = args.grpc_host
+    grpc_port = args.grpc_port
+    domain_uid = args.domain_uid
+
+    tablet_ids = create_tablet(args.owner_idx, args.channels, args.count)
+    print('TabletIds# %s' % ', '.join(map(str, tablet_ids)))
+
+    if args.action == 'initialize':
+        cmd = text_format.Parse(args.proto_file.read(), TTestShardControlRequest.TCmdInitialize())
+        if args.tsserver is not None:
+            host, sep, port = args.tsserver.partition(':')
+            port = int(port) if sep else default_tsserver_port
+            sockaddr = None
+            for _, _, _, _, sockaddr in socket.getaddrinfo(host, port, socket.AF_INET6):
+                break
+            if sockaddr is None:
+                print('Failed to resolve hostname %s' % host, file=sys.stderr)
+                sys.exit(1)
+            cmd.StorageServerHost = sockaddr[0]
+        with multiprocessing.Pool(None) as p:
+            status = 0
+            for r in p.imap_unordered(init_tablet, ((tablet_id, cmd) for tablet_id in tablet_ids), 1):
+                if r is not None:
+                    sys.stderr.write(r)
+                    status = 1
+            sys.exit(status)
diff --git a/ydb/tools/tstool/ya.make b/ydb/tools/tstool/ya.make
new file mode 100644
index 000000000000..217284a1f19b
--- /dev/null
+++ b/ydb/tools/tstool/ya.make
@@ -0,0 +1,16 @@
+PY3_PROGRAM(tstool)
+
+OWNER(alexvru)
+
+PY_MAIN(tstool)
+
+PY_SRCS(
+    TOP_LEVEL
+    tstool.py
+)
+
+PEERDIR(
+    ydb/core/protos
+)
+
+END()
diff --git a/ydb/tools/ya.make b/ydb/tools/ya.make
index e01fbd619c73..25389126d01e 100644
--- a/ydb/tools/ya.make
+++ b/ydb/tools/ya.make
@@ -1,4 +1,6 @@
 RECURSE(
     cfg
     ydbd_slice
+    tsserver
+    tstool
 )