diff --git a/ci/lint/04_install.sh b/ci/lint/04_install.sh
index 542c5b52e3..e7758a8c57 100755
--- a/ci/lint/04_install.sh
+++ b/ci/lint/04_install.sh
@@ -6,6 +6,10 @@
 
 export LC_ALL=C
 
+travis_retry sudo apt update && sudo apt install -y clang-format-9
+sudo update-alternatives --install /usr/bin/clang-format      clang-format      $(which clang-format-9     ) 100
+sudo update-alternatives --install /usr/bin/clang-format-diff clang-format-diff $(which clang-format-diff-9) 100
+
 travis_retry pip3 install codespell==1.17.1
 travis_retry pip3 install flake8==3.8.3
 travis_retry pip3 install vulture==2.3
diff --git a/src/Makefile.am b/src/Makefile.am
index 6e416fa1cf..2e58ef28ef 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -141,6 +141,7 @@ BITCOIN_CORE_H = \
   cachemap.h \
   cachemultimap.h \
   blockfilter.h \
+  bloom.h \
   chain.h \
   chainparams.h \
   chainparamsbase.h \
@@ -170,6 +171,7 @@ BITCOIN_CORE_H = \
   cuckoocache.h \
   ctpl_stl.h \
   cxxtimer.hpp \
+  dbwrapper.h \
   deploymentinfo.h \
   deploymentstatus.h \
   evo/assetlocktx.h \
@@ -217,7 +219,6 @@ BITCOIN_CORE_H = \
   interfaces/wallet.h \
   key.h \
   key_io.h \
-  dbwrapper.h \
   limitedmap.h \
   llmq/blockprocessor.h \
   llmq/chainlocks.h \
@@ -263,6 +264,7 @@ BITCOIN_CORE_H = \
   node/context.h \
   node/psbt.h \
   node/transaction.h \
+  node/ui_interface.h \
   node/utxo_snapshot.h \
   noui.h \
   outputtype.h \
@@ -308,13 +310,12 @@ BITCOIN_CORE_H = \
   support/lockedpool.h \
   sync.h \
   timestampindex.h \
-  threadsafety.h \
   threadinterrupt.h \
+  threadsafety.h \
   timedata.h \
   torcontrol.h \
   txdb.h \
   txmempool.h \
-  ui_interface.h \
   undo.h \
   unordered_lru_cache.h \
   util/bip32.h \
@@ -329,8 +330,6 @@ BITCOIN_CORE_H = \
   util/hasher.h \
   util/hash_type.h \
   util/irange.h \
-  util/spanparsing.h \
-  util/system.h \
   util/asmap.h \
   util/getuniquepath.h \
   util/macros.h \
@@ -345,20 +344,22 @@ BITCOIN_CORE_H = \
   util/ranges_set.h \
   util/sock.h \
   util/string.h \
+  util/spanparsing.h \
+  util/system.h \
   util/time.h \
   util/thread.h \
   util/threadnames.h \
   util/trace.h \
   util/translation.h \
-  util/vector.h \
+  util/ui_change_type.h \
   util/url.h \
   util/vector.h \
   validation.h \
   validationinterface.h \
   versionbits.h \
-  walletinitinterface.h \
   wallet/bdb.h \
   wallet/coincontrol.h \
+  wallet/coinselection.h \
   wallet/context.h \
   wallet/crypter.h \
   wallet/db.h \
@@ -373,7 +374,7 @@ BITCOIN_CORE_H = \
   wallet/walletdb.h \
   wallet/wallettool.h \
   wallet/walletutil.h \
-  wallet/coinselection.h \
+  walletinitinterface.h \
   warnings.h \
   zmq/zmqabstractnotifier.h \
   zmq/zmqnotificationinterface.h \
@@ -423,6 +424,14 @@ libbitcoin_server_a_SOURCES = \
   evo/specialtx.cpp \
   evo/specialtxman.cpp \
   flatfile.cpp \
+  governance/classes.cpp \
+  governance/exceptions.cpp \
+  governance/governance.cpp \
+  governance/object.cpp \
+  governance/validators.cpp \
+  governance/vote.cpp \
+  governance/votedb.cpp \
+  gsl/assert.cpp \
   httprpc.cpp \
   httpserver.cpp \
   i2p.cpp \
@@ -431,14 +440,6 @@ libbitcoin_server_a_SOURCES = \
   index/coinstatsindex.cpp \
   index/txindex.cpp \
   init.cpp \
-  governance/governance.cpp \
-  governance/classes.cpp \
-  governance/exceptions.cpp \
-  governance/object.cpp \
-  governance/validators.cpp \
-  governance/vote.cpp \
-  governance/votedb.cpp \
-  gsl/assert.cpp \
   llmq/quorums.cpp \
   llmq/blockprocessor.cpp \
   llmq/commitment.cpp \
@@ -472,6 +473,7 @@ libbitcoin_server_a_SOURCES = \
   node/interfaces.cpp \
   node/psbt.cpp \
   node/transaction.cpp \
+  node/ui_interface.cpp \
   noui.cpp \
   policy/fees.cpp \
   policy/policy.cpp \
@@ -497,7 +499,6 @@ libbitcoin_server_a_SOURCES = \
   torcontrol.cpp \
   txdb.cpp \
   txmempool.cpp \
-  ui_interface.cpp \
   validation.cpp \
   validationinterface.cpp \
   versionbits.cpp \
diff --git a/src/banman.cpp b/src/banman.cpp
index c7e9cb6744..8f216ab8a0 100644
--- a/src/banman.cpp
+++ b/src/banman.cpp
@@ -6,7 +6,7 @@
 #include <banman.h>
 
 #include <netaddress.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <util/translation.h>
diff --git a/src/bitcoind.cpp b/src/bitcoind.cpp
index def1807316..d56eb01afa 100644
--- a/src/bitcoind.cpp
+++ b/src/bitcoind.cpp
@@ -14,9 +14,9 @@
 #include <init.h>
 #include <interfaces/chain.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <noui.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <util/check.h>
 #include <util/system.h>
 #include <util/strencodings.h>
diff --git a/src/evo/deterministicmns.cpp b/src/evo/deterministicmns.cpp
index 73d72b2be6..184a0a888a 100644
--- a/src/evo/deterministicmns.cpp
+++ b/src/evo/deterministicmns.cpp
@@ -15,7 +15,6 @@
 #include <consensus/validation.h>
 #include <deploymentstatus.h>
 #include <script/standard.h>
-#include <ui_interface.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <univalue.h>
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index e9d1b4cd78..65c2967cfa 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -6,10 +6,10 @@
 
 #include <chainparamsbase.h>
 #include <netbase.h>
+#include <node/ui_interface.h>
 #include <rpc/protocol.h> // For HTTP status codes
 #include <shutdown.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <util/threadnames.h>
diff --git a/src/index/base.cpp b/src/index/base.cpp
index 4803fd68ea..cb860f544d 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -5,9 +5,9 @@
 #include <chainparams.h>
 #include <index/base.h>
 #include <node/blockstorage.h>
+#include <node/ui_interface.h>
 #include <shutdown.h>
 #include <tinyformat.h>
-#include <ui_interface.h>
 #include <util/thread.h>
 #include <util/translation.h>
 #include <validation.h> // For g_chainman
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
index cf22b279c7..a50b991bb4 100644
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -4,8 +4,8 @@
 
 #include <index/disktxpos.h>
 #include <index/txindex.h>
+#include <node/ui_interface.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <validation.h>
diff --git a/src/init.cpp b/src/init.cpp
index 52cb928194..4f69dea571 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -38,6 +38,7 @@
 #include <netbase.h>
 #include <node/blockstorage.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <policy/feerate.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
@@ -54,7 +55,6 @@
 #include <torcontrol.h>
 #include <txdb.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <util/asmap.h>
 #include <util/error.h>
 #include <util/moneystr.h>
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index 82b5b23d9e..4dd73bb624 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -11,8 +11,8 @@
 #include <pubkey.h>                    // For CKeyID and CScriptID (definitions needed in CTxDestination instantiation)
 #include <script/standard.h>           // For CTxDestination
 #include <support/allocators/secure.h> // For SecureString
-#include <ui_interface.h>              // For ChangeType
 #include <util/message.h>
+#include <util/ui_change_type.h>
 
 #include <functional>
 #include <map>
diff --git a/src/llmq/chainlocks.cpp b/src/llmq/chainlocks.cpp
index ae1be6f172..63589eae3b 100644
--- a/src/llmq/chainlocks.cpp
+++ b/src/llmq/chainlocks.cpp
@@ -14,10 +14,10 @@
 #include <masternode/sync.h>
 #include <net_processing.h>
 #include <node/blockstorage.h>
+#include <node/ui_interface.h>
 #include <scheduler.h>
 #include <spork.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <util/thread.h>
 #include <util/time.h>
 #include <validation.h>
diff --git a/src/masternode/sync.cpp b/src/masternode/sync.cpp
index aa732beb6e..afe6d8e150 100644
--- a/src/masternode/sync.cpp
+++ b/src/masternode/sync.cpp
@@ -8,8 +8,8 @@
 #include <governance/governance.h>
 #include <netfulfilledman.h>
 #include <netmessagemaker.h>
+#include <node/ui_interface.h>
 #include <shutdown.h>
-#include <ui_interface.h>
 #include <validation.h>
 #include <util/time.h>
 #include <util/translation.h>
diff --git a/src/net.cpp b/src/net.cpp
index 2777d67abc..2b74a66d96 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -20,10 +20,10 @@
 #include <net_permissions.h>
 #include <netaddress.h>
 #include <netbase.h>
+#include <node/ui_interface.h>
 #include <protocol.h>
 #include <random.h>
 #include <scheduler.h>
-#include <ui_interface.h>
 #include <util/sock.h>
 #include <util/strencodings.h>
 #include <util/thread.h>
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 41447b2ed4..9a7dcf9108 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -30,6 +30,7 @@
 #include <node/blockstorage.h>
 #include <node/coin.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <node/transaction.h>
 #include <policy/feerate.h>
 #include <policy/fees.h>
@@ -44,7 +45,6 @@
 #include <sync.h>
 #include <timedata.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <uint256.h>
 #include <util/check.h>
 #include <util/system.h>
diff --git a/src/ui_interface.cpp b/src/node/ui_interface.cpp
similarity index 99%
rename from src/ui_interface.cpp
rename to src/node/ui_interface.cpp
index c53bedf2b9..f8698c3f73 100644
--- a/src/ui_interface.cpp
+++ b/src/node/ui_interface.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 
 #include <util/translation.h>
 
diff --git a/src/ui_interface.h b/src/node/ui_interface.h
similarity index 94%
rename from src/ui_interface.h
rename to src/node/ui_interface.h
index 0e62269869..425a4cf5b0 100644
--- a/src/ui_interface.h
+++ b/src/node/ui_interface.h
@@ -3,8 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_UI_INTERFACE_H
-#define BITCOIN_UI_INTERFACE_H
+#ifndef BITCOIN_NODE_UI_INTERFACE_H
+#define BITCOIN_NODE_UI_INTERFACE_H
 
 #include <functional>
 #include <memory>
@@ -21,14 +21,6 @@ class connection;
 }
 } // namespace boost
 
-/** General change type (added, updated, removed). */
-enum ChangeType
-{
-    CT_NEW,
-    CT_UPDATED,
-    CT_DELETED
-};
-
 /** Signals for UI communication. */
 class CClientUIInterface
 {
@@ -132,8 +124,8 @@ void InitWarning(const bilingual_str& str);
 
 /** Show error message **/
 bool InitError(const bilingual_str& str);
-inline bool AbortError(const bilingual_str& str) { return InitError(str); }
+constexpr auto AbortError = InitError;
 
 extern CClientUIInterface uiInterface;
 
-#endif // BITCOIN_UI_INTERFACE_H
+#endif // BITCOIN_NODE_UI_INTERFACE_H
diff --git a/src/noui.cpp b/src/noui.cpp
index 195a2d8f8f..3e715a54a0 100644
--- a/src/noui.cpp
+++ b/src/noui.cpp
@@ -7,7 +7,7 @@
 #include <noui.h>
 
 #include <logging.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <util/translation.h>
 
 #include <string>
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 39ca3b04b5..249cb1fb9d 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -34,7 +34,6 @@
 #include <node/context.h>
 #include <noui.h>
 #include <stacktraces.h>
-#include <ui_interface.h>
 #include <uint256.h>
 #include <util/system.h>
 #include <util/threadnames.h>
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 2d6cad3bf7..067dd052a0 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -36,9 +36,9 @@
 #include <interfaces/coinjoin.h>
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
+#include <node/ui_interface.h>
 #include <qt/governancelist.h>
 #include <qt/masternodelist.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index e90b9b4f1d..e484e37603 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -22,7 +22,6 @@
 #include <protocol.h>
 #include <script/script.h>
 #include <script/standard.h>
-#include <ui_interface.h>
 #include <util/system.h>
 
 #include <cmath>
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index 159c3372b0..c0b560a52c 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -16,9 +16,9 @@
 #include <chainparams.h>
 #include <clientversion.h>
 #include <interfaces/node.h>
-#include <policy/policy.h>
 #include <key_io.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
+#include <policy/policy.h>
 #include <util/system.h>
 
 #include <cstdlib>
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index c5f14b5506..34f9d3d8e2 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -21,9 +21,9 @@
 #include <chainparams.h>
 #include <interfaces/node.h>
 #include <key_io.h>
+#include <node/ui_interface.h>
 #include <policy/fees.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <wallet/coincontrol.h>
 #include <wallet/fees.h>
 #include <wallet/wallet.h>
diff --git a/src/qt/splashscreen.cpp b/src/qt/splashscreen.cpp
index 088b97ff93..fab6ef1772 100644
--- a/src/qt/splashscreen.cpp
+++ b/src/qt/splashscreen.cpp
@@ -18,7 +18,6 @@
 #include <qt/guiutil.h>
 #include <qt/networkstyle.h>
 #include <qt/walletmodel.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
index db09d7b09e..a73c1da14a 100644
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -17,7 +17,7 @@
 #include <qt/walletmodel.h>
 
 #include <interfaces/node.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 
 #include <QCalendarWidget>
 #include <QComboBox>
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 049fba2f40..e0b6bcd305 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -21,8 +21,8 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <key_io.h>
+#include <node/ui_interface.h>
 #include <psbt.h>
-#include <ui_interface.h>
 #include <util/system.h> // for GetBoolArg
 #include <util/translation.h>
 #include <wallet/coincontrol.h>
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
index 31b00eed55..39fec3d7cc 100644
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -22,8 +22,8 @@
 #include <qt/walletmodel.h>
 
 #include <interfaces/node.h>
+#include <node/ui_interface.h>
 #include <psbt.h>
-#include <ui_interface.h>
 #include <util/strencodings.h>
 
 #include <QAction>
diff --git a/src/shutdown.cpp b/src/shutdown.cpp
index ea6bf9119f..8421f4f81b 100644
--- a/src/shutdown.cpp
+++ b/src/shutdown.cpp
@@ -6,7 +6,7 @@
 #include <shutdown.h>
 
 #include <logging.h>
-#include <ui_interface.h>
+#include <node/ui_interface.h>
 #include <warnings.h>
 
 #include <config/bitcoin-config.h>
diff --git a/src/timedata.cpp b/src/timedata.cpp
index cdc65b65c7..6ea0b4b9d5 100644
--- a/src/timedata.cpp
+++ b/src/timedata.cpp
@@ -9,8 +9,8 @@
 #include <timedata.h>
 
 #include <netaddress.h>
+#include <node/ui_interface.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <util/system.h>
 #include <util/translation.h>
 #include <warnings.h>
diff --git a/src/txdb.cpp b/src/txdb.cpp
index 646ef850fd..fae9ff1128 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -5,12 +5,12 @@
 
 #include <txdb.h>
 
+#include <node/ui_interface.h>
 #include <pow.h>
 #include <random.h>
 #include <shutdown.h>
 #include <uint256.h>
 #include <util/system.h>
-#include <ui_interface.h>
 #include <util/translation.h>
 #include <util/vector.h>
 
diff --git a/src/util/ui_change_type.h b/src/util/ui_change_type.h
new file mode 100644
index 0000000000..1db761a18d
--- /dev/null
+++ b/src/util/ui_change_type.h
@@ -0,0 +1,15 @@
+// Copyright (c) 2012-2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_UI_CHANGE_TYPE_H
+#define BITCOIN_UTIL_UI_CHANGE_TYPE_H
+
+/** General change type (added, updated, removed). */
+enum ChangeType {
+    CT_NEW,
+    CT_UPDATED,
+    CT_DELETED
+};
+
+#endif // BITCOIN_UTIL_UI_CHANGE_TYPE_H
diff --git a/src/validation.cpp b/src/validation.cpp
index 8b8cc4ff30..bc670438b3 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -24,6 +24,7 @@
 #include <logging/timer.h>
 #include <node/blockstorage.h>
 #include <node/coinstats.h>
+#include <node/ui_interface.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <pow.h>
@@ -39,7 +40,6 @@
 #include <tinyformat.h>
 #include <txdb.h>
 #include <txmempool.h>
-#include <ui_interface.h>
 #include <uint256.h>
 #include <undo.h>
 #include <util/check.h> // For NDEBUG compile time check
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
index aa783cfd3f..4b432de993 100644
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -9,8 +9,8 @@
 #include <interfaces/wallet.h>
 #include <net.h>
 #include <node/context.h>
+#include <node/ui_interface.h>
 #include <univalue.h>
-#include <ui_interface.h>
 #include <util/check.h>
 #include <util/error.h>
 #include <util/system.h>
diff --git a/src/wallet/interfaces.cpp b/src/wallet/interfaces.cpp
index e6acbd0c10..4eb3574608 100644
--- a/src/wallet/interfaces.cpp
+++ b/src/wallet/interfaces.cpp
@@ -15,10 +15,10 @@
 #include <script/standard.h>
 #include <support/allocators/secure.h>
 #include <sync.h>
-#include <ui_interface.h>
 #include <uint256.h>
 #include <util/check.h>
 #include <util/system.h>
+#include <util/ui_change_type.h>
 #include <validation.h>
 #include <wallet/context.h>
 #include <wallet/fees.h>
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 775ea04ec6..ee5caa82fa 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -16,11 +16,11 @@
 #include <psbt.h>
 #include <saltedhasher.h>
 #include <tinyformat.h>
-#include <ui_interface.h>
 #include <util/message.h>
 #include <util/string.h>
 #include <util/system.h>
 #include <util/strencodings.h>
+#include <util/ui_change_type.h>
 #include <validationinterface.h>
 #include <wallet/coincontrol.h>
 #include <wallet/crypter.h>