diff --git a/tonlib/tonlib/ExtClientOutbound.cpp b/tonlib/tonlib/ExtClientOutbound.cpp
new file mode 100644
index 0000000..a20a8c5
--- /dev/null
+++ b/tonlib/tonlib/ExtClientOutbound.cpp
@@ -0,0 +1,66 @@
+
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2017-2019 Telegram Systems LLP
+*/
+#include "ExtClientOutbound.h"
+#include <map>
+namespace tonlib {
+
+class ExtClientOutboundImp : public ExtClientOutbound {
+ public:
+  ExtClientOutboundImp(td::unique_ptr<ExtClientOutbound::Callback> callback) : callback_(std::move(callback)) {
+  }
+
+  void check_ready(td::Promise<td::Unit> promise) override {
+    promise.set_error(td::Status::Error("Not supported"));
+  }
+
+  void send_query(std::string name, td::BufferSlice data, td::Timestamp timeout,
+                  td::Promise<td::BufferSlice> promise) override {
+    auto query_id = next_query_id_++;
+    queries_[query_id] = std::move(promise);
+    callback_->request(query_id, data.as_slice().str());
+  }
+
+  void on_query_result(td::int64 id, td::Result<td::BufferSlice> r_data, td::Promise<td::Unit> promise) override {
+    auto it = queries_.find(id);
+    if (it == queries_.end()) {
+      promise.set_error(td::Status::Error(400, "Unknown query id"));
+    }
+    it->second.set_result(std::move(r_data));
+    queries_.erase(it);
+    promise.set_value(td::Unit());
+  }
+
+ private:
+  td::unique_ptr<ExtClientOutbound::Callback> callback_;
+  td::int64 next_query_id_{1};
+  std::map<td::int64, td::Promise<td::BufferSlice>> queries_;
+
+  void tear_down() override {
+    for (auto &it : queries_) {
+      it.second.set_error(td::Status::Error(400, "Query cancelled"));
+    }
+    queries_.clear();
+  }
+};
+
+td::actor::ActorOwn<ExtClientOutbound> ExtClientOutbound::create(td::unique_ptr<Callback> callback) {
+  return td::actor::create_actor<ExtClientOutboundImp>("ExtClientOutbound", std::move(callback));
+}
+}  // namespace tonlib
diff --git a/tonlib/tonlib/ExtClientOutbound.h b/tonlib/tonlib/ExtClientOutbound.h
new file mode 100644
index 0000000..3635fd1
--- /dev/null
+++ b/tonlib/tonlib/ExtClientOutbound.h
@@ -0,0 +1,37 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2017-2019 Telegram Systems LLP
+*/
+#pragma once
+#include "td/actor/actor.h"
+
+#include "adnl/adnl-ext-client.h"
+
+namespace tonlib {
+class ExtClientOutbound : public ton::adnl::AdnlExtClient {
+ public:
+  class Callback {
+   public:
+    virtual ~Callback() {
+    }
+    virtual void request(td::int64 id, std::string data) = 0;
+  };
+  virtual void on_query_result(td::int64 id, td::Result<td::BufferSlice> r_data, td::Promise<td::Unit> promise) = 0;
+  static td::actor::ActorOwn<ExtClientOutbound> create(td::unique_ptr<Callback> callback);
+};
+
+}  // namespace tonlib