Get neighbors' msg queues from other nodes

tl/generate/scheme/ton_api.tl

@@ -410,6 +410,9 @@ tonNode.success = tonNode.Success;
 tonNode.archiveNotFound = tonNode.ArchiveInfo;
 tonNode.archiveInfo id:long = tonNode.ArchiveInfo;
 
+tonNode.outMsgQueueProof queue_proof:bytes block_state_proof:bytes = tonNode.OutMsgQueueProof;
+tonNode.outMsgQueueProofEmpty = tonNode.OutMsgQueueProof;
+
 ---functions---
 
 tonNode.getNextBlockDescription prev_block:tonNode.blockIdExt = tonNode.BlockDescription;
@@ -441,6 +444,7 @@ tonNode.downloadBlockProofLinks blocks:(vector tonNode.blockIdExt) = tonNode.Dat
 tonNode.downloadKeyBlockProofLinks blocks:(vector tonNode.blockIdExt) = tonNode.DataList;
 tonNode.getArchiveInfo masterchain_seqno:int = tonNode.ArchiveInfo;
 tonNode.getArchiveSlice archive_id:long offset:long max_size:int = tonNode.Data;
+tonNode.getOutMsgQueueProof block_id:tonNode.blockIdExt dst_workchain:int dst_shard:long = tonNode.OutMsgQueueProof;
 
 tonNode.getCapabilities = tonNode.Capabilities;
 

validator/CMakeLists.txt

@@ -43,6 +43,7 @@ set(VALIDATOR_HEADERS
   fabric.h
   interfaces/db.h
   interfaces/external-message.h
+  interfaces/out-msg-queue-proof.h
   interfaces/proof.h
   interfaces/shard.h
   interfaces/signature-set.h

validator/full-node-shard.cpp

@@ -19,6 +19,7 @@
 #include "auto/tl/ton_api.h"
 #include "overlays.h"
 #include "td/utils/SharedSlice.h"
+#include "td/utils/overloaded.h"
 #include "full-node-shard.hpp"
 #include "full-node-shard-queries.hpp"
 
@@ -34,6 +35,7 @@
 #include "net/download-proof.hpp"
 #include "net/get-next-key-blocks.hpp"
 #include "net/download-archive-slice.hpp"
+#include "impl/out-msg-queue-proof.hpp"
 
 #include "td/utils/Random.h"
 
@@ -574,6 +576,31 @@ void FullNodeShardImpl::process_query(adnl::AdnlNodeIdShort src, ton_api::tonNod
                           query.offset_, query.max_size_, std::move(promise));
 }
 
+void FullNodeShardImpl::process_query(adnl::AdnlNodeIdShort src, ton_api::tonNode_getOutMsgQueueProof &query,
+                                      td::Promise<td::BufferSlice> promise) {
+  BlockIdExt block_id = create_block_id(query.block_id_);
+  ShardIdFull dst_shard(query.dst_workchain_, query.dst_shard_);
+  if (!block_id.is_valid_ext()) {
+    promise.set_error(td::Status::Error("invalid block_id"));
+    return;
+  }
+  if (!dst_shard.is_valid_ext()) {
+    promise.set_error(td::Status::Error("invalid shard"));
+    return;
+  }
+  auto P = td::PromiseCreator::lambda(
+      [promise = std::move(promise)](td::Result<tl_object_ptr<ton_api::tonNode_outMsgQueueProof>> R) mutable {
+        if (R.is_error()) {
+          promise.set_result(create_serialize_tl_object<ton_api::tonNode_outMsgQueueProofEmpty>());
+        } else {
+          promise.set_result(serialize_tl_object(R.move_as_ok(), true));
+        }
+      });
+  td::actor::create_actor<BuildOutMsgQueueProof>("buildqueueproof", block_id, dst_shard, validator_manager_,
+                                                 std::move(P))
+      .release();
+}
+
 void FullNodeShardImpl::receive_query(adnl::AdnlNodeIdShort src, td::BufferSlice query,
                                       td::Promise<td::BufferSlice> promise) {
   if (!active_) {
@@ -791,6 +818,32 @@ void FullNodeShardImpl::download_archive(BlockSeqno masterchain_seqno, std::stri
       .release();
 }
 
+void FullNodeShardImpl::download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                                     td::Promise<td::Ref<OutMsgQueueProof>> promise) {
+  // TODO: maybe more complex download (like other requests here)
+  // TODO: estimate max size
+  auto &b = choose_neighbour();
+  auto P = td::PromiseCreator::lambda(
+      [=, promise = create_neighbour_promise(b, std::move(promise))](td::Result<td::BufferSlice> R) mutable {
+        if (R.is_error()) {
+          promise.set_result(R.move_as_error());
+          return;
+        }
+        TRY_RESULT_PROMISE(promise, f, fetch_tl_object<ton_api::tonNode_OutMsgQueueProof>(R.move_as_ok(), true));
+        ton_api::downcast_call(*f, td::overloaded(
+                                       [&](ton_api::tonNode_outMsgQueueProofEmpty &x) {
+                                         promise.set_error(td::Status::Error("node doesn't have this block"));
+                                       },
+                                       [&](ton_api::tonNode_outMsgQueueProof &x) {
+                                         promise.set_result(OutMsgQueueProof::fetch(block_id, dst_shard, x));
+                                       }));
+      });
+  td::BufferSlice query = create_serialize_tl_object<ton_api::tonNode_getOutMsgQueueProof>(
+      create_tl_block_id(block_id), dst_shard.workchain, dst_shard.shard);
+  td::actor::send_closure(overlays_, &overlay::Overlays::send_query_via, b.adnl_id, adnl_id_, overlay_id_,
+                          "get_msg_queue", std::move(P), timeout, std::move(query), 1 << 20, rldp_);
+}
+
 void FullNodeShardImpl::set_handle(BlockHandle handle, td::Promise<td::Unit> promise) {
   CHECK(!handle_);
   handle_ = std::move(handle);

validator/full-node-shard.h

@@ -62,6 +62,8 @@ class FullNodeShard : public td::actor::Actor {
                                    td::Promise<std::vector<BlockIdExt>> promise) = 0;
   virtual void download_archive(BlockSeqno masterchain_seqno, std::string tmp_dir, td::Timestamp timeout,
                                 td::Promise<std::string> promise) = 0;
+  virtual void download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                            td::Promise<td::Ref<OutMsgQueueProof>> promise) = 0;
 
   virtual void set_handle(BlockHandle handle, td::Promise<td::Unit> promise) = 0;
 

validator/full-node-shard.hpp

@@ -133,6 +133,8 @@ class FullNodeShardImpl : public FullNodeShard {
                      td::Promise<td::BufferSlice> promise);
   void process_query(adnl::AdnlNodeIdShort src, ton_api::tonNode_getArchiveSlice &query,
                      td::Promise<td::BufferSlice> promise);
+  void process_query(adnl::AdnlNodeIdShort src, ton_api::tonNode_getOutMsgQueueProof &query,
+                     td::Promise<td::BufferSlice> promise);
   // void process_query(adnl::AdnlNodeIdShort src, ton_api::tonNode_prepareNextKeyBlockProof &query,
   //                   td::Promise<td::BufferSlice> promise);
   void receive_query(adnl::AdnlNodeIdShort src, td::BufferSlice query, td::Promise<td::BufferSlice> promise);
@@ -164,6 +166,8 @@ class FullNodeShardImpl : public FullNodeShard {
                            td::Promise<std::vector<BlockIdExt>> promise) override;
   void download_archive(BlockSeqno masterchain_seqno, std::string tmp_dir, td::Timestamp timeout,
                         td::Promise<std::string> promise) override;
+  void download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                    td::Promise<td::Ref<OutMsgQueueProof>> promise) override;
 
   void set_handle(BlockHandle handle, td::Promise<td::Unit> promise) override;
 

validator/full-node.cpp

@@ -356,6 +356,18 @@ void FullNodeImpl::download_archive(BlockSeqno masterchain_seqno, std::string tm
                           std::move(promise));
 }
 
+void FullNodeImpl::download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                                td::Promise<td::Ref<OutMsgQueueProof>> promise) {
+  auto shard = get_shard(block_id.shard_full());
+  if (shard.empty()) {
+    VLOG(FULL_NODE_WARNING) << "dropping download msg queue query to unknown shard";
+    promise.set_error(td::Status::Error(ErrorCode::notready, "shard not ready"));
+    return;
+  }
+  td::actor::send_closure(shard, &FullNodeShard::download_out_msg_queue_proof, block_id, dst_shard, timeout,
+                          std::move(promise));
+}
+
 td::actor::ActorId<FullNodeShard> FullNodeImpl::get_shard(ShardIdFull shard, bool exact) {
   if (!exact) {
     ShardIdFull s = shard;
@@ -546,6 +558,11 @@ void FullNodeImpl::start_up() {
       td::actor::send_closure(id_, &FullNodeImpl::download_archive, masterchain_seqno, std::move(tmp_dir), timeout,
                               std::move(promise));
     }
+    void download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                      td::Promise<td::Ref<OutMsgQueueProof>> promise) override {
+      td::actor::send_closure(id_, &FullNodeImpl::download_out_msg_queue_proof, block_id, dst_shard, timeout,
+                              std::move(promise));
+    }
 
     void new_key_block(BlockHandle handle) override {
       td::actor::send_closure(id_, &FullNodeImpl::new_key_block, std::move(handle));

validator/full-node.hpp

@@ -73,6 +73,8 @@ class FullNodeImpl : public FullNode {
   void get_next_key_blocks(BlockIdExt block_id, td::Timestamp timeout, td::Promise<std::vector<BlockIdExt>> promise);
   void download_archive(BlockSeqno masterchain_seqno, std::string tmp_dir, td::Timestamp timeout,
                         td::Promise<std::string> promise);
+  void download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                    td::Promise<td::Ref<OutMsgQueueProof>> promise);
 
   void got_key_block_proof(td::Ref<ProofLink> proof);
   void got_zero_block_state(td::Ref<ShardState> state);

validator/impl/CMakeLists.txt

@@ -15,6 +15,7 @@ set(TON_VALIDATOR_SOURCE
   ihr-message.cpp
   liteserver.cpp
   message-queue.cpp
+  out-msg-queue-proof.cpp
   proof.cpp
   shard.cpp
   signature-set.cpp
@@ -32,13 +33,13 @@ set(TON_VALIDATOR_SOURCE
   ihr-message.hpp
   liteserver.hpp
   message-queue.hpp
+  out-msg-queue-proof.hpp
   proof.hpp
   shard.hpp
   signature-set.hpp
   top-shard-descr.hpp
   validate-query.hpp
-  validator-set.hpp
-)
+  validator-set.hpp)
 
 add_library(ton_validator STATIC ${TON_VALIDATOR_SOURCE})
 

validator/impl/collator-impl.h

@@ -205,7 +205,7 @@ class Collator final : public td::actor::Actor {
   std::vector<ExtMessage::Hash> bad_ext_msgs_, delay_ext_msgs_;
   Ref<vm::Cell> shard_account_blocks_;  // ShardAccountBlocks
 
-  std::map<td::Bits256, Ref<BlockData>> blocks_with_state_proofs_;
+  std::map<td::Bits256, Ref<vm::Cell>> block_state_proofs_;
   std::vector<vm::MerkleProofBuilder> neighbor_proof_builders_;
   std::vector<Ref<vm::Cell>> collated_roots_;
 
@@ -238,8 +238,7 @@ class Collator final : public td::actor::Actor {
   void after_get_aux_shard_state(ton::BlockIdExt blkid, td::Result<Ref<ShardState>> res);
   bool fix_one_processed_upto(block::MsgProcessedUpto& proc, const ton::ShardIdFull& owner);
   bool fix_processed_upto(block::MsgProcessedUptoCollection& upto);
-  void got_neighbor_block_data(td::Result<Ref<BlockData>> res);
-  void got_neighbor_block_state(int i, td::Result<Ref<ShardState>> res);
+  void got_neighbor_msg_queue(unsigned i, td::Result<Ref<OutMsgQueueProof>> R);
   bool adjust_shard_config();
   bool store_shard_fees(ShardIdFull shard, const block::CurrencyCollection& fees,
                         const block::CurrencyCollection& created);

validator/impl/collator.cpp

@@ -501,7 +501,13 @@ void Collator::after_get_block_data(int idx, td::Result<Ref<BlockData>> res) {
       prev_mc_block = prev_block_data[0];
       mc_block_root = prev_mc_block->root_cell();
     }
-    blocks_with_state_proofs_[prev_block_data[idx]->root_cell()->get_hash().bits()] = prev_block_data[idx];
+    Ref<vm::Cell> root = prev_block_data[idx]->root_cell();
+    auto proof = create_block_state_proof(root);
+    if (proof.is_error()) {
+      fatal_error(proof.move_as_error());
+      return;
+    }
+    block_state_proofs_.emplace(root->get_hash().bits(), proof.move_as_ok());
   }
   check_pending();
 }
@@ -613,54 +619,39 @@ bool Collator::request_neighbor_msg_queues() {
     }
     neighbors_.emplace_back(*shard_ptr);
   }
-  int i = 0;
+  unsigned i = 0;
   neighbor_proof_builders_.resize(neighbors_.size());
   for (block::McShardDescr& descr : neighbors_) {
     LOG(DEBUG) << "neighbor #" << i << " : " << descr.blk_.to_str();
-    if (descr.blk_.seqno() != 0) {
-      ++pending;
-      send_closure_later(manager, &ValidatorManager::wait_block_data_short, descr.blk_, priority(), timeout,
-                         [self = get_self(), i](td::Result<Ref<BlockData>> res) {
-                           LOG(DEBUG) << "got answer to wait_block_data for neighbor #" << i;
-                           send_closure_later(std::move(self), &Collator::got_neighbor_block_data, std::move(res));
-                         });
-    }
     ++pending;
-    send_closure_later(manager, &ValidatorManager::wait_block_state_short, descr.blk_, priority(), timeout,
-                       [self = get_self(), i](td::Result<Ref<ShardState>> res) {
-                         LOG(DEBUG) << "got answer to wait_block_state for neighbor #" << i;
-                         send_closure_later(std::move(self), &Collator::got_neighbor_block_state, i, std::move(res));
+    send_closure_later(manager, &ValidatorManager::wait_out_msg_queue_proof, descr.blk_, shard_, priority(), timeout,
+                       [self = get_self(), i](td::Result<Ref<OutMsgQueueProof>> res) {
+                         LOG(DEBUG) << "got msg queue for neighbor #" << i;
+                         send_closure_later(std::move(self), &Collator::got_neighbor_msg_queue, i, std::move(res));
                        });
     ++i;
   }
   return true;
 }
 
-void Collator::got_neighbor_block_data(td::Result<Ref<BlockData>> res) {
+void Collator::got_neighbor_msg_queue(unsigned i, td::Result<Ref<OutMsgQueueProof>> R) {
   --pending;
-  if (res.is_error()) {
-    fatal_error(res.move_as_error());
+  if (R.is_error()) {
+    fatal_error(R.move_as_error());
     return;
   }
-  auto block_data = res.move_as_ok();
-  blocks_with_state_proofs_[block_data->root_cell()->get_hash().bits()] = block_data;
-  check_pending();
-}
-
-void Collator::got_neighbor_block_state(int i, td::Result<Ref<ShardState>> res) {
-  --pending;
-  if (res.is_error()) {
-    fatal_error(res.move_as_error());
+  auto res = R.move_as_ok();
+  BlockIdExt block_id = neighbors_.at(i).blk_;
+  if (res->block_state_proof_.not_null()) {
+    block_state_proofs_.emplace(block_id.root_hash, res->block_state_proof_);
+  }
+  neighbor_proof_builders_.at(i) = vm::MerkleProofBuilder{res->state_root_};
+  auto state = ShardStateQ::fetch(block_id, {}, neighbor_proof_builders_.at(i).root());
+  if (state.is_error()) {
+    fatal_error(state.move_as_error());
     return;
   }
-  Ref<ShardState> state = res.move_as_ok();
-  neighbor_proof_builders_.at(i) = vm::MerkleProofBuilder{state->root_cell()};
-  auto new_state = ShardStateQ::fetch(state->get_block_id(), {}, neighbor_proof_builders_.at(i).root());
-  if (new_state.is_error()) {
-    fatal_error(new_state.move_as_error());
-    return;
-  }
-  auto outq_descr_res = new_state.move_as_ok()->message_queue();
+  auto outq_descr_res = state.move_as_ok()->message_queue();
   if (outq_descr_res.is_error()) {
     fatal_error(outq_descr_res.move_as_error());
     return;
@@ -3992,17 +3983,8 @@ bool Collator::create_collated_data() {
     collated_roots_.push_back(std::move(cell));
   }
   // 2. Proofs for hashes of states: previous states + neighbors
-  for (const auto& p : blocks_with_state_proofs_) {
-    vm::MerkleProofBuilder mpb{p.second->root_cell()};
-    block::gen::Block::Record block;
-    if (!tlb::unpack_cell(mpb.root(), block) || block.state_update->load_cell().is_error()) {
-      return fatal_error("cannot generate Merkle proof for previous block");
-    }
-    Ref<vm::Cell> proof = mpb.extract_proof();
-    if (proof.is_null()) {
-      return fatal_error("cannot generate Merkle proof for previous block");
-    }
-    collated_roots_.push_back(std::move(proof));
+  for (const auto& p : block_state_proofs_) {
+    collated_roots_.push_back(p.second);
   }
   // 3. Previous state proof (only shadchains)
   std::map<td::Bits256, Ref<vm::Cell>> proofs;

validator/impl/out-msg-queue-proof.cpp

@@ -0,0 +1,245 @@
+/*
+    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/>.
+*/
+#include "out-msg-queue-proof.hpp"
+#include "interfaces/proof.h"
+#include "shard.hpp"
+#include "vm/cells/MerkleProof.h"
+#include "common/delay.h"
+#include "interfaces/validator-manager.h"
+
+namespace ton {
+
+namespace validator {
+
+td::Result<td::Ref<OutMsgQueueProof>> OutMsgQueueProof::fetch(BlockIdExt block_id, ShardIdFull dst_shard,
+                                                              const ton_api::tonNode_outMsgQueueProof &f) {
+  Ref<vm::Cell> block_state_proof;
+  td::Bits256 state_root_hash;
+  if (block_id.seqno() == 0) {
+    if (!f.block_state_proof_.empty()) {
+      return td::Status::Error("expected empty block state proof");
+    }
+    state_root_hash = block_id.root_hash;
+  } else {
+    TRY_RESULT_ASSIGN(block_state_proof, vm::std_boc_deserialize(f.block_state_proof_.as_slice()));
+    TRY_RESULT_ASSIGN(state_root_hash, unpack_block_state_proof(block_id, block_state_proof));
+  }
+
+  TRY_RESULT(queue_proof, vm::std_boc_deserialize(f.queue_proof_.as_slice()));
+  auto state_root = vm::MerkleProof::virtualize(queue_proof, 1);
+  if (state_root.is_null()) {
+    return td::Status::Error("invalid queue proof");
+  }
+  if (state_root->get_hash().as_slice() != state_root_hash.as_slice()) {
+    return td::Status::Error("state root hash mismatch");
+  }
+
+  // TODO: validate
+  return Ref<OutMsgQueueProof>(true, std::move(state_root), std::move(block_state_proof));
+}
+
+td::Result<tl_object_ptr<ton_api::tonNode_outMsgQueueProof>> OutMsgQueueProof::serialize(
+    BlockIdExt block_id, ShardIdFull dst_shard, Ref<vm::Cell> state_root, Ref<vm::Cell> block_root) {
+  vm::MerkleProofBuilder mpb{std::move(state_root)};
+  TRY_RESULT(state, ShardStateQ::fetch(block_id, {}, mpb.root()));
+  TRY_RESULT(outq_descr, state->message_queue());
+
+  // TODO: add only required part of msg queue
+  td::HashSet<vm::Cell::Hash> visited;
+  std::function<void(Ref<vm::Cell>)> dfs = [&](Ref<vm::Cell> cell) {
+    if (!visited.insert(cell->get_hash()).second) {
+      return;
+    }
+    vm::CellSlice cs(vm::NoVm(), cell);
+    for (unsigned i = 0; i < cs.size_refs(); i++) {
+      dfs(cs.prefetch_ref(i));
+    }
+  };
+  dfs(outq_descr->root_cell());
+
+  TRY_RESULT(queue_proof, vm::std_boc_serialize(mpb.extract_proof()));
+
+  td::BufferSlice block_state_proof;
+  if (block_id.seqno() != 0) {
+    TRY_RESULT(proof, create_block_state_proof(std::move(block_root)));
+    TRY_RESULT_ASSIGN(block_state_proof, vm::std_boc_serialize(std::move(proof), 31));
+  }
+
+  return create_tl_object<ton_api::tonNode_outMsgQueueProof>(std::move(queue_proof), std::move(block_state_proof));
+}
+
+void WaitOutMsgQueueProof::alarm() {
+  abort_query(td::Status::Error(ErrorCode::timeout, "timeout"));
+}
+
+void WaitOutMsgQueueProof::abort_query(td::Status reason) {
+  if (promise_) {
+    if (priority_ > 0 || (reason.code() != ErrorCode::timeout && reason.code() != ErrorCode::notready)) {
+      LOG(WARNING) << "aborting wait msg queue query for " << block_id_.to_str() << " priority=" << priority_ << ": "
+                   << reason;
+    } else {
+      LOG(DEBUG) << "aborting wait msg queue query for " << block_id_.to_str() << " priority=" << priority_ << ": "
+                 << reason;
+    }
+    promise_.set_error(
+        reason.move_as_error_prefix(PSTRING() << "failed to get msg queue for " << block_id_.to_str() << ": "));
+  }
+  stop();
+}
+
+void WaitOutMsgQueueProof::finish_query(Ref<OutMsgQueueProof> result) {
+  promise_.set_result(std::move(result));
+  stop();
+}
+
+void WaitOutMsgQueueProof::start_up() {
+  alarm_timestamp() = timeout_;
+  if (local_) {
+    run_local();
+  } else {
+    run_net();
+  }
+}
+
+void WaitOutMsgQueueProof::run_local() {
+  ++pending;
+  td::actor::send_closure(manager_, &ValidatorManager::wait_block_state_short, block_id_, priority_, timeout_,
+                          [SelfId = actor_id(this)](td::Result<Ref<ShardState>> R) {
+                            if (R.is_error()) {
+                              td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::abort_query,
+                                                      R.move_as_error_prefix("failed to get shard state"));
+                            } else {
+                              td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::got_state_root,
+                                                      R.move_as_ok()->root_cell());
+                            }
+                          });
+  if (block_id_.seqno() != 0) {
+    ++pending;
+    td::actor::send_closure(manager_, &ValidatorManager::wait_block_data_short, block_id_, priority_, timeout_,
+                            [SelfId = actor_id(this)](td::Result<Ref<BlockData>> R) {
+                              if (R.is_error()) {
+                                td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::abort_query,
+                                                        R.move_as_error_prefix("failed to get block data"));
+                              } else {
+                                td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::got_block_root,
+                                                        R.move_as_ok()->root_cell());
+                              }
+                            });
+  }
+}
+
+void WaitOutMsgQueueProof::got_state_root(Ref<vm::Cell> root) {
+  state_root_ = std::move(root);
+  if (--pending == 0) {
+    run_local_cont();
+  }
+}
+
+void WaitOutMsgQueueProof::got_block_root(Ref<vm::Cell> root) {
+  block_root_ = std::move(root);
+  if (--pending == 0) {
+    run_local_cont();
+  }
+}
+
+void WaitOutMsgQueueProof::run_local_cont() {
+  Ref<vm::Cell> block_state_proof;
+  if (block_id_.seqno() != 0) {
+    auto R = create_block_state_proof(std::move(block_root_));
+    if (R.is_error()) {
+      abort_query(R.move_as_error_prefix("failed to create block state proof"));
+      return;
+    }
+    block_state_proof = R.move_as_ok();
+  }
+  finish_query(td::Ref<OutMsgQueueProof>(true, std::move(state_root_), std::move(block_state_proof)));
+}
+
+void WaitOutMsgQueueProof::run_net() {
+  auto P =
+      td::PromiseCreator::lambda([SelfId = actor_id(this), block_id = block_id_](td::Result<Ref<OutMsgQueueProof>> R) {
+        if (R.is_error()) {
+          LOG(DEBUG) << "failed to get msg queue for " << block_id.to_str() << " from net: " << R.move_as_error();
+          delay_action([SelfId]() mutable { td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::run_net); },
+                       td::Timestamp::in(0.1));
+        } else {
+          td::actor::send_closure(SelfId, &WaitOutMsgQueueProof::finish_query, R.move_as_ok());
+        }
+      });
+
+  td::actor::send_closure(manager_, &ValidatorManager::send_get_out_msg_queue_proof_request, block_id_, dst_shard_,
+                          priority_, std::move(P));
+}
+
+void BuildOutMsgQueueProof::abort_query(td::Status reason) {
+  if (promise_) {
+    LOG(WARNING) << "failed to build msg queue proof for " << block_id_.to_str() << ": " << reason;
+    promise_.set_error(
+        reason.move_as_error_prefix(PSTRING() << "failed to build msg queue proof for " << block_id_.to_str() << ": "));
+  }
+  stop();
+}
+
+void BuildOutMsgQueueProof::start_up() {
+  ++pending;
+  td::actor::send_closure(manager_, &ValidatorManagerInterface::get_shard_state_from_db_short, block_id_,
+                          [SelfId = actor_id(this)](td::Result<Ref<ShardState>> R) {
+                            if (R.is_error()) {
+                              td::actor::send_closure(SelfId, &BuildOutMsgQueueProof::abort_query,
+                                                      R.move_as_error_prefix("failed to get shard state"));
+                            } else {
+                              td::actor::send_closure(SelfId, &BuildOutMsgQueueProof::got_state_root,
+                                                      R.move_as_ok()->root_cell());
+                            }
+                          });
+  if (block_id_.seqno() != 0) {
+    ++pending;
+    td::actor::send_closure(manager_, &ValidatorManagerInterface::get_block_data_from_db_short, block_id_,
+                            [SelfId = actor_id(this)](td::Result<Ref<BlockData>> R) {
+                              if (R.is_error()) {
+                                td::actor::send_closure(SelfId, &BuildOutMsgQueueProof::abort_query,
+                                                        R.move_as_error_prefix("failed to get block data"));
+                              } else {
+                                td::actor::send_closure(SelfId, &BuildOutMsgQueueProof::got_block_root,
+                                                        R.move_as_ok()->root_cell());
+                              }
+                            });
+  }
+}
+
+void BuildOutMsgQueueProof::got_state_root(Ref<vm::Cell> root) {
+  state_root_ = std::move(root);
+  if (--pending == 0) {
+    build_proof();
+  }
+}
+
+void BuildOutMsgQueueProof::got_block_root(Ref<vm::Cell> root) {
+  block_root_ = std::move(root);
+  if (--pending == 0) {
+    build_proof();
+  }
+}
+
+void BuildOutMsgQueueProof::build_proof() {
+  promise_.set_result(
+      OutMsgQueueProof::serialize(block_id_, dst_shard_, std::move(state_root_), std::move(block_root_)));
+  stop();
+}
+
+}  // namespace validator
+}  // namespace ton

validator/impl/out-msg-queue-proof.hpp

@@ -0,0 +1,109 @@
+/*
+    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/>.
+*/
+#pragma once
+#include "vm/cells.h"
+#include "ton/ton-types.h"
+#include "auto/tl/ton_api.h"
+#include "interfaces/out-msg-queue-proof.h"
+#include "td/actor/actor.h"
+
+namespace ton {
+
+namespace validator {
+using td::Ref;
+
+class ValidatorManager;
+class ValidatorManagerInterface;
+
+class WaitOutMsgQueueProof : public td::actor::Actor {
+ public:
+  WaitOutMsgQueueProof(BlockIdExt block_id, ShardIdFull dst_shard, bool local, td::uint32 priority,
+                       td::actor::ActorId<ValidatorManager> manager, td::Timestamp timeout,
+                       td::Promise<Ref<OutMsgQueueProof>> promise)
+      : block_id_(std::move(block_id))
+      , dst_shard_(dst_shard)
+      , local_(local)
+      , priority_(priority)
+      , manager_(manager)
+      , timeout_(timeout)
+      , promise_(std::move(promise)) {
+  }
+
+  void update_timeout(td::Timestamp timeout, td::uint32 priority) {
+    timeout_ = timeout;
+    alarm_timestamp() = timeout_;
+    priority_ = priority;
+  }
+
+  void abort_query(td::Status reason);
+  void finish_query(Ref<OutMsgQueueProof> result);
+  void alarm() override;
+
+  void start_up() override;
+
+  void run_local();
+  void got_state_root(Ref<vm::Cell> root);
+  void got_block_root(Ref<vm::Cell> root);
+  void run_local_cont();
+
+  void run_net();
+
+
+ private:
+  BlockIdExt block_id_;
+  ShardIdFull dst_shard_;
+  bool local_;
+  td::uint32 priority_;
+
+  td::actor::ActorId<ValidatorManager> manager_;
+  td::Timestamp timeout_;
+  td::Promise<Ref<OutMsgQueueProof>> promise_;
+
+  Ref<vm::Cell> state_root_, block_root_;
+  unsigned pending = 0;
+};
+
+class BuildOutMsgQueueProof : public td::actor::Actor {
+ public:
+  BuildOutMsgQueueProof(BlockIdExt block_id, ShardIdFull dst_shard,
+      td::actor::ActorId<ValidatorManagerInterface> manager,
+      td::Promise<tl_object_ptr<ton_api::tonNode_outMsgQueueProof>> promise)
+      : block_id_(std::move(block_id))
+      , dst_shard_(dst_shard)
+      , manager_(manager)
+      , promise_(std::move(promise)) {
+  }
+
+  void abort_query(td::Status reason);
+  void start_up() override;
+  void got_state_root(Ref<vm::Cell> root);
+  void got_block_root(Ref<vm::Cell> root);
+  void build_proof();
+
+ private:
+  BlockIdExt block_id_;
+  ShardIdFull dst_shard_;
+
+  td::actor::ActorId<ValidatorManagerInterface> manager_;
+  td::Promise<tl_object_ptr<ton_api::tonNode_outMsgQueueProof>> promise_;
+
+  Ref<vm::Cell> state_root_, block_root_;
+  unsigned pending = 0;
+};
+
+}  // namespace validator
+}  // namespace ton

validator/impl/proof.cpp

@@ -162,5 +162,40 @@ td::Result<Ref<vm::Cell>> ProofQ::get_signatures_root() const {
   return proof.signatures->prefetch_ref();
 }
 
+td::Result<td::Ref<vm::Cell>> create_block_state_proof(td::Ref<vm::Cell> root) {
+  if (root.is_null()) {
+    return td::Status::Error("root is null");
+  }
+  vm::MerkleProofBuilder mpb{std::move(root)};
+  block::gen::Block::Record block;
+  if (!tlb::unpack_cell(mpb.root(), block) || block.state_update->load_cell().is_error()) {
+    return td::Status::Error("invalid block");
+  }
+  Ref<vm::Cell> proof = mpb.extract_proof();
+  if (proof.is_null()) {
+    return td::Status::Error("failed to create proof");
+  }
+  return proof;
+}
+
+td::Result<RootHash> unpack_block_state_proof(BlockIdExt block_id, td::Ref<vm::Cell> proof) {
+  auto virt_root = vm::MerkleProof::virtualize(proof, 1);
+  if (virt_root.is_null()) {
+    return td::Status::Error("invalid Merkle proof");
+  }
+  if (virt_root->get_hash().as_slice() != block_id.root_hash.as_slice()) {
+    return td::Status::Error("hash mismatch");
+  }
+  block::gen::Block::Record block;
+  if (!tlb::unpack_cell(virt_root, block)) {
+    return td::Status::Error("invalid block");
+  }
+  vm::CellSlice upd_cs{vm::NoVmSpec(), block.state_update};
+  if (!(upd_cs.is_special() && upd_cs.prefetch_long(8) == 4 && upd_cs.size_ext() == 0x20228)) {
+    return td::Status::Error("invalid Merkle update");
+  }
+  return upd_cs.prefetch_ref(1)->get_hash(0).bits();
+}
+
 }  // namespace validator
 }  // namespace ton

validator/interfaces/out-msg-queue-proof.h

@@ -0,0 +1,42 @@
+/*
+    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/>.
+*/
+#pragma once
+#include "vm/cells.h"
+#include "ton/ton-types.h"
+#include "auto/tl/ton_api.h"
+
+namespace ton {
+
+namespace validator {
+using td::Ref;
+
+struct OutMsgQueueProof : public td::CntObject {
+  OutMsgQueueProof(Ref<vm::Cell> state_root, Ref<vm::Cell> block_state_proof)
+      : state_root_(std::move(state_root)), block_state_proof_(std::move(block_state_proof)) {
+  }
+
+  Ref<vm::Cell> state_root_;
+  Ref<vm::Cell> block_state_proof_;
+
+  static td::Result<td::Ref<OutMsgQueueProof>> fetch(BlockIdExt block_id, ShardIdFull dst_shard,
+                                                     const ton_api::tonNode_outMsgQueueProof &f);
+  static td::Result<tl_object_ptr<ton_api::tonNode_outMsgQueueProof>> serialize(
+      BlockIdExt block_id, ShardIdFull dst_shard, Ref<vm::Cell> state_root, Ref<vm::Cell> block_root);
+};
+
+}  // namespace validator
+}  // namespace ton

validator/interfaces/proof.h

@@ -48,6 +48,9 @@ class Proof : virtual public ProofLink {
   virtual td::Result<td::Ref<ProofLink>> export_as_proof_link() const = 0;
 };
 
+td::Result<td::Ref<vm::Cell>> create_block_state_proof(td::Ref<vm::Cell> root);
+td::Result<RootHash> unpack_block_state_proof(BlockIdExt block_id, td::Ref<vm::Cell> proof);
+
 }  // namespace validator
 
 }  // namespace ton

validator/interfaces/validator-manager.h

@@ -29,6 +29,7 @@
 #include "liteserver.h"
 #include "crypto/vm/db/DynamicBagOfCellsDb.h"
 #include "validator-session/validator-session-types.h"
+#include "impl/out-msg-queue-proof.hpp"
 
 namespace ton {
 
@@ -128,6 +129,8 @@ class ValidatorManager : public ValidatorManagerInterface {
   virtual void send_ihr_message(td::Ref<IhrMessage> message) = 0;
   virtual void send_top_shard_block_description(td::Ref<ShardTopBlockDescription> desc) = 0;
   virtual void send_block_broadcast(BlockBroadcast broadcast) = 0;
+  virtual void send_get_out_msg_queue_proof_request(BlockIdExt id, ShardIdFull dst_shard, td::uint32 priority,
+                                                    td::Promise<td::Ref<OutMsgQueueProof>> promise) = 0;
 
   virtual void update_shard_client_state(BlockIdExt masterchain_block_id, td::Promise<td::Unit> promise) = 0;
   virtual void get_shard_client_state(bool from_db, td::Promise<BlockIdExt> promise) = 0;

validator/manager-disk.hpp

@@ -152,6 +152,10 @@ class ValidatorManagerImpl : public ValidatorManager {
                         td::Promise<td::Ref<ShardState>> promise) override;
   void wait_block_state_short(BlockIdExt block_id, td::uint32 priority, td::Timestamp timeout,
                               td::Promise<td::Ref<ShardState>> promise) override;
+  void wait_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::uint32 priority, td::Timestamp timeout,
+                                td::Promise<td::Ref<OutMsgQueueProof>> promise) override {
+    UNREACHABLE();
+  }
 
   void set_block_data(BlockHandle handle, td::Ref<BlockData> data, td::Promise<td::Unit> promise) override;
   void wait_block_data(BlockHandle handle, td::uint32 priority, td::Timestamp,
@@ -250,6 +254,10 @@ class ValidatorManagerImpl : public ValidatorManager {
   void send_top_shard_block_description(td::Ref<ShardTopBlockDescription> desc) override;
   void send_block_broadcast(BlockBroadcast broadcast) override {
   }
+  void send_get_out_msg_queue_proof_request(BlockIdExt id, ShardIdFull dst_shard, td::uint32 priority,
+                                            td::Promise<td::Ref<OutMsgQueueProof>> promise) override {
+    UNREACHABLE();
+  }
 
   void update_shard_client_state(BlockIdExt masterchain_block_id, td::Promise<td::Unit> promise) override;
   void get_shard_client_state(bool from_db, td::Promise<BlockIdExt> promise) override;

validator/manager-hardfork.hpp

@@ -182,6 +182,10 @@ class ValidatorManagerImpl : public ValidatorManager {
                         td::Promise<td::Ref<ShardState>> promise) override;
   void wait_block_state_short(BlockIdExt block_id, td::uint32 priority, td::Timestamp timeout,
                               td::Promise<td::Ref<ShardState>> promise) override;
+  void wait_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::uint32 priority, td::Timestamp timeout,
+                                td::Promise<td::Ref<OutMsgQueueProof>> promise) override {
+    UNREACHABLE();
+  }
 
   void set_block_data(BlockHandle handle, td::Ref<BlockData> data, td::Promise<td::Unit> promise) override {
     UNREACHABLE();
@@ -314,6 +318,10 @@ class ValidatorManagerImpl : public ValidatorManager {
   }
   void send_block_broadcast(BlockBroadcast broadcast) override {
   }
+  void send_get_out_msg_queue_proof_request(BlockIdExt id, ShardIdFull dst_shard, td::uint32 priority,
+                                            td::Promise<td::Ref<OutMsgQueueProof>> promise) override {
+    UNREACHABLE();
+  }
 
   void update_shard_client_state(BlockIdExt masterchain_block_id, td::Promise<td::Unit> promise) override {
     UNREACHABLE();

validator/manager.cpp

@@ -453,24 +453,18 @@ void ValidatorManagerImpl::add_shard_block_description(td::Ref<ShardTopBlockDesc
     }
     shard_blocks_[ShardTopBlockDescriptionId{desc->block_id().shard_full(), desc->catchain_seqno()}] = desc;
     VLOG(VALIDATOR_DEBUG) << "new shard block descr for " << desc->block_id();
-    if (opts_->need_monitor(desc->block_id().shard_full()) && last_masterchain_block_handle_ &&
-        last_masterchain_seqno_ > 0 && desc->generated_at() < last_masterchain_block_handle_->unix_time() + 60) {
-        delay_action(
-          [SelfId = actor_id(this), desc]() {
-            auto P = td::PromiseCreator::lambda([](td::Result<td::Ref<ShardState>> R) {
-              if (R.is_error()) {
-                auto S = R.move_as_error();
-                if (S.code() != ErrorCode::timeout && S.code() != ErrorCode::notready) {
-                  VLOG(VALIDATOR_NOTICE) << "failed to get shard state: " << S;
-                } else {
-                  VLOG(VALIDATOR_DEBUG) << "failed to get shard state: " << S;
-                }
-              }
-            });
-            td::actor::send_closure(SelfId, &ValidatorManager::wait_block_state_short, desc->block_id(), 0,
-                                    td::Timestamp::in(60.0), std::move(P));
-          },
-          td::Timestamp::in(1.0));
+    if (opts_->need_monitor(desc->block_id().shard_full())) {
+      auto P = td::PromiseCreator::lambda([](td::Result<td::Ref<ShardState>> R) {
+        if (R.is_error()) {
+          auto S = R.move_as_error();
+          if (S.code() != ErrorCode::timeout && S.code() != ErrorCode::notready) {
+            VLOG(VALIDATOR_NOTICE) << "failed to get shard state: " << S;
+          } else {
+            VLOG(VALIDATOR_DEBUG) << "failed to get shard state: " << S;
+          }
+        }
+      });
+      wait_block_state_short(desc->block_id(), 0, td::Timestamp::in(60.0), std::move(P));
     }
   }
 }
@@ -606,6 +600,30 @@ void ValidatorManagerImpl::wait_block_state_short(BlockIdExt block_id, td::uint3
   get_block_handle(block_id, true, std::move(P));
 }
 
+void ValidatorManagerImpl::wait_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::uint32 priority,
+                                                    td::Timestamp timeout,
+                                                    td::Promise<td::Ref<OutMsgQueueProof>> promise) {
+  auto key = std::make_pair(block_id, dst_shard);
+  auto it = wait_out_msg_queue_proof_.find(key);
+  if (it == wait_out_msg_queue_proof_.end()) {
+    auto P = td::PromiseCreator::lambda(
+        [SelfId = actor_id(this), block_id, dst_shard](td::Result<td::Ref<OutMsgQueueProof>> R) {
+          td::actor::send_closure(SelfId, &ValidatorManagerImpl::finished_wait_msg_queue, block_id, dst_shard,
+                                  std::move(R));
+        });
+    auto id = td::actor::create_actor<WaitOutMsgQueueProof>("waitmsgqueue", block_id, dst_shard,
+                                                            opts_->need_monitor(block_id.shard_full()), priority,
+                                                            actor_id(this), td::Timestamp::in(10.0), std::move(P))
+                  .release();
+    wait_out_msg_queue_proof_[key].actor_ = id;
+    it = wait_out_msg_queue_proof_.find(key);
+  }
+
+  it->second.waiting_.emplace_back(timeout, priority, std::move(promise));
+  auto X = it->second.get_timeout();
+  td::actor::send_closure(it->second.actor_, &WaitOutMsgQueueProof::update_timeout, X.first, X.second);
+}
+
 void ValidatorManagerImpl::wait_block_data(BlockHandle handle, td::uint32 priority, td::Timestamp timeout,
                                            td::Promise<td::Ref<BlockData>> promise) {
   auto it = wait_block_data_.find(handle->id());
@@ -1037,6 +1055,40 @@ void ValidatorManagerImpl::finished_wait_data(BlockHandle handle, td::Result<td:
   }
 }
 
+void ValidatorManagerImpl::finished_wait_msg_queue(BlockIdExt block_id, ShardIdFull dst_shard,
+                                                   td::Result<td::Ref<OutMsgQueueProof>> R) {
+  auto it = wait_out_msg_queue_proof_.find({block_id, dst_shard});
+  if (it != wait_out_msg_queue_proof_.end()) {
+    if (R.is_error()) {
+      auto S = R.move_as_error();
+      if (S.code() != ErrorCode::timeout) {
+        for (auto &X : it->second.waiting_) {
+          X.promise.set_error(S.clone());
+        }
+      } else {
+        auto X = it->second.get_timeout();
+        auto P = td::PromiseCreator::lambda(
+            [SelfId = actor_id(this), block_id, dst_shard](td::Result<td::Ref<OutMsgQueueProof>> R) {
+              td::actor::send_closure(SelfId, &ValidatorManagerImpl::finished_wait_msg_queue, block_id, dst_shard,
+                                      std::move(R));
+            });
+        auto id = td::actor::create_actor<WaitOutMsgQueueProof>("waitmsgqueue", block_id, dst_shard,
+                                                                opts_->need_monitor(block_id.shard_full()), X.second,
+                                                                actor_id(this), X.first, std::move(P))
+                      .release();
+        it->second.actor_ = id;
+        return;
+      }
+    } else {
+      auto r = R.move_as_ok();
+      for (auto &X : it->second.waiting_) {
+        X.promise.set_result(r);
+      }
+    }
+    wait_out_msg_queue_proof_.erase(it);
+  }
+}
+
 void ValidatorManagerImpl::set_block_state(BlockHandle handle, td::Ref<ShardState> state,
                                            td::Promise<td::Ref<ShardState>> promise) {
   auto P = td::PromiseCreator::lambda(
@@ -1410,6 +1462,12 @@ void ValidatorManagerImpl::send_block_broadcast(BlockBroadcast broadcast) {
   callback_->send_broadcast(std::move(broadcast));
 }
 
+void ValidatorManagerImpl::send_get_out_msg_queue_proof_request(BlockIdExt id, ShardIdFull dst_shard,
+                                                                td::uint32 priority,
+                                                                td::Promise<td::Ref<OutMsgQueueProof>> promise) {
+  callback_->download_out_msg_queue_proof(id, dst_shard, td::Timestamp::in(10.0), std::move(promise));
+}
+
 void ValidatorManagerImpl::start_up() {
   db_ = create_db_actor(actor_id(this), db_root_);
   lite_server_cache_ = create_liteserver_cache_actor(actor_id(this), db_root_);

validator/manager.hpp

@@ -183,6 +183,8 @@ class ValidatorManagerImpl : public ValidatorManager {
   };
   std::map<BlockIdExt, WaitList<WaitBlockState, td::Ref<ShardState>>> wait_state_;
   std::map<BlockIdExt, WaitList<WaitBlockData, td::Ref<BlockData>>> wait_block_data_;
+  std::map<std::pair<BlockIdExt, ShardIdFull>, WaitList<WaitOutMsgQueueProof, td::Ref<OutMsgQueueProof>>>
+      wait_out_msg_queue_proof_;
 
   struct WaitBlockHandle {
     std::vector<td::Promise<BlockHandle>> waiting_;
@@ -357,6 +359,8 @@ class ValidatorManagerImpl : public ValidatorManager {
                         td::Promise<td::Ref<ShardState>> promise) override;
   void wait_block_state_short(BlockIdExt block_id, td::uint32 priority, td::Timestamp timeout,
                               td::Promise<td::Ref<ShardState>> promise) override;
+  void wait_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::uint32 priority, td::Timestamp timeout,
+                                td::Promise<td::Ref<OutMsgQueueProof>> promise) override;
 
   void set_block_data(BlockHandle handle, td::Ref<BlockData> data, td::Promise<td::Unit> promise) override;
   void wait_block_data(BlockHandle handle, td::uint32 priority, td::Timestamp,
@@ -444,6 +448,8 @@ class ValidatorManagerImpl : public ValidatorManager {
   void send_ihr_message(td::Ref<IhrMessage> message) override;
   void send_top_shard_block_description(td::Ref<ShardTopBlockDescription> desc) override;
   void send_block_broadcast(BlockBroadcast broadcast) override;
+  void send_get_out_msg_queue_proof_request(BlockIdExt id, ShardIdFull dst_shard, td::uint32 priority,
+                                            td::Promise<td::Ref<OutMsgQueueProof>> promise) override;
 
   void update_shard_client_state(BlockIdExt masterchain_block_id, td::Promise<td::Unit> promise) override;
   void get_shard_client_state(bool from_db, td::Promise<BlockIdExt> promise) override;
@@ -478,6 +484,7 @@ class ValidatorManagerImpl : public ValidatorManager {
 
   void finished_wait_state(BlockHandle handle, td::Result<td::Ref<ShardState>> R);
   void finished_wait_data(BlockHandle handle, td::Result<td::Ref<BlockData>> R);
+  void finished_wait_msg_queue(BlockIdExt block_id, ShardIdFull dst_shard, td::Result<td::Ref<OutMsgQueueProof>> R);
 
   void start_up() override;
   void started(ValidatorManagerInitResult result);

validator/validator.h

@@ -34,6 +34,7 @@
 #include "interfaces/proof.h"
 #include "interfaces/shard.h"
 #include "catchain/catchain-types.h"
+#include "interfaces/out-msg-queue-proof.h"
 
 namespace ton {
 
@@ -131,6 +132,8 @@ class ValidatorManagerInterface : public td::actor::Actor {
                                      td::Promise<std::vector<BlockIdExt>> promise) = 0;
     virtual void download_archive(BlockSeqno masterchain_seqno, std::string tmp_dir, td::Timestamp timeout,
                                   td::Promise<std::string> promise) = 0;
+    virtual void download_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::Timestamp timeout,
+                                              td::Promise<td::Ref<OutMsgQueueProof>> promise) = 0;
 
     virtual void new_key_block(BlockHandle handle) = 0;
   };
@@ -212,6 +215,10 @@ class ValidatorManagerInterface : public td::actor::Actor {
   virtual void wait_block_state_short(BlockIdExt block_id, td::uint32 priority, td::Timestamp timeout,
                                       td::Promise<td::Ref<ShardState>> promise) = 0;
 
+  virtual void wait_out_msg_queue_proof(BlockIdExt block_id, ShardIdFull dst_shard, td::uint32 priority,
+                                        td::Timestamp timeout,
+                                        td::Promise<td::Ref<OutMsgQueueProof>> promise) = 0;
+
   virtual void get_archive_id(BlockSeqno masterchain_seqno, td::Promise<td::uint64> promise) = 0;
   virtual void get_archive_slice(td::uint64 archive_id, td::uint64 offset, td::uint32 limit,
                                  td::Promise<td::BufferSlice> promise) = 0;