diff --git a/bin/akula-ddl.rs b/bin/akula-ddl.rs
index d999153..47d5fb9 100644
--- a/bin/akula-ddl.rs
+++ b/bin/akula-ddl.rs
@@ -1,4 +1,7 @@
-use akula::downloader::{chain_config, opts::Opts, Downloader};
+use akula::{
+    downloader::{opts::Opts, Downloader},
+    sentry::chain_config,
+};
 
 use akula::kv;
 use std::sync::Arc;
diff --git a/src/downloader/downloader_impl.rs b/src/downloader/downloader_impl.rs
index b3dd034..32ffd73 100644
--- a/src/downloader/downloader_impl.rs
+++ b/src/downloader/downloader_impl.rs
@@ -1,6 +1,5 @@
 use crate::{
     downloader::{
-        chain_config::{ChainConfig, ChainsConfig},
         headers::{
             fetch_receive_stage::FetchReceiveStage, fetch_request_stage::FetchRequestStage,
             header_slices, header_slices::HeaderSlices,
@@ -9,13 +8,16 @@ use crate::{
             HeaderSlicesView,
         },
         opts::Opts,
+    },
+    kv,
+    models::BlockNumber,
+    sentry::{
+        chain_config::{ChainConfig, ChainsConfig},
         sentry_client,
         sentry_client::SentryClient,
         sentry_client_connector,
         sentry_client_reactor::SentryClientReactor,
     },
-    kv,
-    models::BlockNumber,
 };
 use futures_core::Stream;
 use parking_lot::RwLock;
diff --git a/src/downloader/downloader_tests.rs b/src/downloader/downloader_tests.rs
index 14326c5..2246144 100644
--- a/src/downloader/downloader_tests.rs
+++ b/src/downloader/downloader_tests.rs
@@ -1,6 +1,7 @@
 use crate::{
-    downloader::{chain_config, opts::Opts, sentry_client_mock::SentryClientMock, Downloader},
+    downloader::{opts::Opts, Downloader},
     kv, new_mem_database,
+    sentry::{chain_config, sentry_client_mock::SentryClientMock},
 };
 use std::sync::Arc;
 
diff --git a/src/downloader/headers/fetch_receive_stage.rs b/src/downloader/headers/fetch_receive_stage.rs
index 5aecca0..b656102 100644
--- a/src/downloader/headers/fetch_receive_stage.rs
+++ b/src/downloader/headers/fetch_receive_stage.rs
@@ -1,13 +1,13 @@
 use crate::{
-    downloader::{
-        headers::{
-            header_slices,
-            header_slices::{HeaderSlice, HeaderSliceStatus, HeaderSlices},
-        },
+    downloader::headers::{
+        header_slices,
+        header_slices::{HeaderSlice, HeaderSliceStatus, HeaderSlices},
+    },
+    models::{BlockHeader as Header, BlockNumber},
+    sentry::{
         messages::{BlockHeadersMessage, EthMessageId, Message},
         sentry_client_reactor::SentryClientReactor,
     },
-    models::{BlockHeader as Header, BlockNumber},
 };
 use futures_core::Stream;
 use parking_lot::RwLock;
diff --git a/src/downloader/headers/fetch_request_stage.rs b/src/downloader/headers/fetch_request_stage.rs
index 76618c8..a1deb6d 100644
--- a/src/downloader/headers/fetch_request_stage.rs
+++ b/src/downloader/headers/fetch_request_stage.rs
@@ -1,16 +1,16 @@
 use crate::{
-    downloader::{
+    downloader::headers::{
+        header_slice_status_watch::HeaderSliceStatusWatch,
+        header_slices,
+        header_slices::{HeaderSliceStatus, HeaderSlices},
+    },
+    models::BlockNumber,
+    sentry::{
         block_id,
-        headers::{
-            header_slice_status_watch::HeaderSliceStatusWatch,
-            header_slices,
-            header_slices::{HeaderSliceStatus, HeaderSlices},
-        },
         messages::{GetBlockHeadersMessage, GetBlockHeadersMessageParams, Message},
         sentry_client::PeerFilter,
         sentry_client_reactor::{SendMessageError, SentryClientReactor},
     },
-    models::BlockNumber,
 };
 use parking_lot::{RwLock, RwLockUpgradableReadGuard};
 use std::{
diff --git a/src/downloader/mod.rs b/src/downloader/mod.rs
index 8347b6b..69c2fe8 100644
--- a/src/downloader/mod.rs
+++ b/src/downloader/mod.rs
@@ -1,20 +1,9 @@
-pub mod block_id;
-pub mod chain_config;
-pub mod chain_id;
 mod downloader_impl;
-mod message_decoder;
-pub mod messages;
+mod headers;
 pub mod opts;
-pub mod sentry_address;
-pub mod sentry_client;
-mod sentry_client_connector;
-pub mod sentry_client_impl;
-mod sentry_client_mock;
 
 #[cfg(test)]
 mod downloader_tests;
-mod headers;
-mod sentry_client_reactor;
 
 mod ui_system;
 mod ui_view;
diff --git a/src/downloader/opts.rs b/src/downloader/opts.rs
index 7b12822..d1275c1 100644
--- a/src/downloader/opts.rs
+++ b/src/downloader/opts.rs
@@ -1,4 +1,4 @@
-use crate::downloader::sentry_address::SentryAddress;
+use crate::sentry::sentry_address::SentryAddress;
 use anyhow::anyhow;
 use directories::ProjectDirs;
 use std::str::FromStr;
diff --git a/src/lib.rs b/src/lib.rs
index 4deb6c9..600d738 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -30,6 +30,7 @@ pub mod execution;
 pub mod kv;
 pub mod models;
 pub mod res;
+pub mod sentry;
 pub mod stagedsync;
 pub mod stages;
 mod state;
diff --git a/src/downloader/block_id.rs b/src/sentry/block_id.rs
similarity index 100%
rename from src/downloader/block_id.rs
rename to src/sentry/block_id.rs
diff --git a/src/downloader/chain_config.rs b/src/sentry/chain_config.rs
similarity index 100%
rename from src/downloader/chain_config.rs
rename to src/sentry/chain_config.rs
diff --git a/src/downloader/chain_config.toml b/src/sentry/chain_config.toml
similarity index 100%
rename from src/downloader/chain_config.toml
rename to src/sentry/chain_config.toml
diff --git a/src/downloader/chain_id.rs b/src/sentry/chain_id.rs
similarity index 100%
rename from src/downloader/chain_id.rs
rename to src/sentry/chain_id.rs
diff --git a/src/downloader/message_decoder.rs b/src/sentry/message_decoder.rs
similarity index 98%
rename from src/downloader/message_decoder.rs
rename to src/sentry/message_decoder.rs
index 333afff..ca50c48 100644
--- a/src/downloader/message_decoder.rs
+++ b/src/sentry/message_decoder.rs
@@ -1,4 +1,4 @@
-use crate::downloader::messages::*;
+use super::messages::*;
 
 pub fn decode_rlp_message(id: EthMessageId, message_bytes: &[u8]) -> anyhow::Result<Message> {
     let message: Message = match id {
@@ -34,7 +34,7 @@ impl rlp::Encodable for Message {
 
 #[cfg(test)]
 mod tests {
-    use crate::downloader::{
+    use super::super::{
         block_id::BlockId,
         message_decoder::decode_rlp_message,
         messages::{
diff --git a/src/downloader/messages.rs b/src/sentry/messages.rs
similarity index 95%
rename from src/downloader/messages.rs
rename to src/sentry/messages.rs
index 23e57bc..2e51fa3 100644
--- a/src/downloader/messages.rs
+++ b/src/sentry/messages.rs
@@ -1,7 +1,5 @@
-use crate::{
-    downloader::block_id::BlockId,
-    models::{Block as BlockType, BlockHeader as HeaderType},
-};
+use super::block_id::BlockId;
+use crate::models::{Block as BlockType, BlockHeader as HeaderType};
 use ethereum_types::H256;
 use rlp_derive::*;
 
diff --git a/src/sentry/mod.rs b/src/sentry/mod.rs
new file mode 100644
index 0000000..660592b
--- /dev/null
+++ b/src/sentry/mod.rs
@@ -0,0 +1,11 @@
+pub mod block_id;
+pub mod chain_config;
+pub mod chain_id;
+mod message_decoder;
+pub mod messages;
+pub mod sentry_address;
+pub mod sentry_client;
+pub mod sentry_client_connector;
+pub mod sentry_client_impl;
+pub mod sentry_client_mock;
+pub mod sentry_client_reactor;
diff --git a/src/downloader/sentry_address.rs b/src/sentry/sentry_address.rs
similarity index 100%
rename from src/downloader/sentry_address.rs
rename to src/sentry/sentry_address.rs
diff --git a/src/downloader/sentry_client.rs b/src/sentry/sentry_client.rs
similarity index 98%
rename from src/downloader/sentry_client.rs
rename to src/sentry/sentry_client.rs
index 5aad141..12ec24f 100644
--- a/src/downloader/sentry_client.rs
+++ b/src/sentry/sentry_client.rs
@@ -1,4 +1,4 @@
-use crate::downloader::{
+use super::{
     chain_config::ChainConfig,
     messages::{EthMessageId, Message},
 };
diff --git a/src/downloader/sentry_client_connector.rs b/src/sentry/sentry_client_connector.rs
similarity index 98%
rename from src/downloader/sentry_client_connector.rs
rename to src/sentry/sentry_client_connector.rs
index 8209535..6592f5d 100644
--- a/src/downloader/sentry_client_connector.rs
+++ b/src/sentry/sentry_client_connector.rs
@@ -1,4 +1,4 @@
-use crate::downloader::{
+use super::{
     sentry_address::SentryAddress, sentry_client::SentryClient,
     sentry_client_impl::SentryClientImpl,
 };
diff --git a/src/downloader/sentry_client_impl.rs b/src/sentry/sentry_client_impl.rs
similarity index 98%
rename from src/downloader/sentry_client_impl.rs
rename to src/sentry/sentry_client_impl.rs
index dc03923..d37e363 100644
--- a/src/downloader/sentry_client_impl.rs
+++ b/src/sentry/sentry_client_impl.rs
@@ -1,6 +1,4 @@
-use crate::downloader::{
-    message_decoder, messages::*, sentry_address::SentryAddress, sentry_client::*,
-};
+use super::{message_decoder, messages::*, sentry_address::SentryAddress, sentry_client::*};
 use async_trait::async_trait;
 use ethereum_interfaces::{sentry as grpc_sentry, types as grpc_types};
 use futures_core::Stream;
diff --git a/src/downloader/sentry_client_mock.rs b/src/sentry/sentry_client_mock.rs
similarity index 94%
rename from src/downloader/sentry_client_mock.rs
rename to src/sentry/sentry_client_mock.rs
index 691e34b..ccb08b2 100644
--- a/src/downloader/sentry_client_mock.rs
+++ b/src/sentry/sentry_client_mock.rs
@@ -1,4 +1,4 @@
-use crate::downloader::{
+use super::{
     messages::{EthMessageId, Message},
     sentry_client::{MessageFromPeer, MessageFromPeerStream, PeerFilter, SentryClient, Status},
 };
@@ -64,3 +64,9 @@ impl SentryClient for SentryClientMock {
         }
     }
 }
+
+impl Default for SentryClientMock {
+    fn default() -> Self {
+        Self::new()
+    }
+}
diff --git a/src/downloader/sentry_client_reactor.rs b/src/sentry/sentry_client_reactor.rs
similarity index 99%
rename from src/downloader/sentry_client_reactor.rs
rename to src/sentry/sentry_client_reactor.rs
index 970deb5..dee701a 100644
--- a/src/downloader/sentry_client_reactor.rs
+++ b/src/sentry/sentry_client_reactor.rs
@@ -1,4 +1,4 @@
-use crate::downloader::{
+use super::{
     messages::{EthMessageId, Message},
     sentry_client::*,
     sentry_client_connector,
@@ -242,7 +242,7 @@ impl Drop for EventLoopReceiveMessagesSendersDropper {
 }
 
 mod stream_factory {
-    use crate::downloader::{sentry_client::MessageFromPeerStream, sentry_client_reactor::*};
+    use super::super::{sentry_client::MessageFromPeerStream, sentry_client_reactor::*};
     use tokio::sync::Mutex;
 
     fn make_receive_stream(