diff --git a/apps/aechannel/src/aesc_fsm.erl b/apps/aechannel/src/aesc_fsm.erl
index 133c047c0b..85dfb1b319 100644
--- a/apps/aechannel/src/aesc_fsm.erl
+++ b/apps/aechannel/src/aesc_fsm.erl
@@ -183,6 +183,8 @@
                       [aesc_offchain_update:update()]}
                    | {reestablish, OffChainTx :: aetx_sign:signed_tx()}.
 
+-type log() :: aesc_window:window({Op :: atom(), Type :: atom(), erlang:timestamp(), Msg :: term()}).
+
 -opaque state_name() :: awaiting_open
                       | awaiting_reestablish
                       | initialized
@@ -218,7 +220,7 @@
               , latest = undefined     :: latest_op()
               , ongoing_update = false :: boolean()
               , last_reported_update   :: undefined | non_neg_integer()
-              , log                    :: aesc_window:window()
+              , log                    :: log()
               , strict_checks = true   :: boolean()
               }).
 
diff --git a/apps/aechannel/src/aesc_fsm_min_depth_watcher.erl b/apps/aechannel/src/aesc_fsm_min_depth_watcher.erl
index 4d2ffdcf3e..8ee898f853 100644
--- a/apps/aechannel/src/aesc_fsm_min_depth_watcher.erl
+++ b/apps/aechannel/src/aesc_fsm_min_depth_watcher.erl
@@ -18,6 +18,19 @@
 -export([get_txs_since/2]).
 
 -define(GEN_SERVER_OPTS, []).
+-define(IS_INFO_OF_SCENARIO_HAS_TX(X),
+        ( is_tuple(X)
+          andalso (tuple_size(X) =:= 2)
+          andalso ( is_tuple(element(1, X))
+                    andalso (tuple_size(element(1, X)) =:= 2)
+                    andalso is_binary(element(1, element(1, X)))
+                    andalso is_binary(element(2, element(1, X)))
+                  )
+          andalso ( is_map(element(2, X))
+                    andalso (map_size(element(2, X)) =:= 3
+                             orelse map_size(element(2, X)) =:= 4)
+                  )
+        ) ).
 -define(IS_SCENARIO(S),
         ( (S =:= top)
           orelse (S =:= next_block)
@@ -25,7 +38,7 @@
           orelse ( is_tuple(S)
                    andalso (tuple_size(S) =:= 2)
                    andalso (element(1, S) =:= has_tx)
-                   %% TODO Check element(2, S)
+                   andalso ?IS_INFO_OF_SCENARIO_HAS_TX(element(2, S))
                  )
         ) ).
 
@@ -34,11 +47,21 @@
             , chan_vsn
             , last_block                  %% last time we updated channel vsn
             , last_top                    %% the block hash of the last check
-            , tx_log = aesc_window:new()
-            , rpt_log = aesc_window:new()
+            , tx_log = aesc_window:new() :: tx_log()
+            , rpt_log = aesc_window:new() :: rpt_log()
             , closing = false
             , requests = [] }).
 
+-record(tx_log_entry,
+        { key   :: tx_log_entry_key()
+        , value :: tx_log_entry_value()
+        }).
+
+-record(rpt_log_entry,
+        { key   :: {changed_on_chain | closing_on_chain | closed_on_chain, tx_hash()}
+        , value :: #{ atom() := term() }
+        }).
+
 -type mode()       :: close
                     | unlock
                     | tx_hash
@@ -64,7 +87,11 @@
 
 -type block_hash() :: binary().
 -type tx_hash()    :: binary().
--type scenario()   :: top | next_block | fork_switch | {has_tx, tx_hash()}.
+-type info_of_scenario_has_tx() :: {tx_log_entry_key(), tx_log_entry_value()}.
+-type scenario()   :: top
+                    | next_block
+                    | fork_switch
+                    | {has_tx, info_of_scenario_has_tx()}.
 -type chan_vsn()   :: undefined | { aesc_channels:round()
                                   , aesc_channels:solo_round()
                                   , aesc_channels:is_active()
@@ -77,9 +104,18 @@
                                   , lock_period  := aesc_channels:lock_period()
                                   , locked_until := aesc_channels:locked_until() }.
 
+-type tx_log_entry_key() :: {tx_hash(), block_hash()}.
+-type tx_log_entry_value() :: #{ tx           => aetx_sign:signed_tx()
+                               , block_hash   := block_hash()
+                               , block_origin := chain
+                               , type := aetx:tx_type() }.
+-type tx_log() :: aesc_window:window(#tx_log_entry{}).
+
+-type rpt_log() :: aesc_window:window(#rpt_log_entry{}).
+
 -type cache() :: #{ mode := mode()
-                  , tx_log := aesc_window:window()
-                  , rpt_log := aesc_window:window()
+                  , tx_log := tx_log()
+                  , rpt_log := rpt_log()
                   , last_block := block_hash()
                   , chan_vsn   := chan_vsn()
                   , block_hash => block_hash()
@@ -341,11 +377,12 @@ init_cache_(#st{ last_block = LastBlock
 
 %% The TxLog relies on the custom tx events (remember that it's a bounded list)
 find_tx_in_block(BHash, TxLog) ->
-    case aesc_window:info_find([{block_hash, BHash}], 2, TxLog) of
+    Filter = [{block_hash, BHash}],
+    case aesc_window:info_find(Filter, #tx_log_entry.value, TxLog) of
         false ->
             false;
-        LastTx ->
-            LastTx
+        X = #tx_log_entry{} ->
+            {X#tx_log_entry.key, X#tx_log_entry.value}
     end.
 
 %% We do an async_dirty activity for minimal overhead. Note that the analysis
@@ -475,9 +512,9 @@ check_req(#{mode := unlock} = R, #st{chan_id = ChId, chan_vsn = Vsn} = St, C) ->
 check_req(#{mode := watch} = R, #st{chan_id = ChId} = St,
           #{scenario := Scenario, top_hash := Hash } = C)
   when ?IS_SCENARIO(Scenario) ->
+    lager:debug("Scenario = ~p", [Scenario]),
     case Scenario of
-        {has_tx, {_, #{ type    := TxType
-                      , tx_hash := TxHash }}} ->
+        {has_tx, {{TxHash,_}, #{ type    := TxType }}} ->
             {Ch, C1} = get_channel(ChId, Hash, C),
             {#{ height := H }, C2} = top_info(Hash, C1),
             case Ch of
@@ -495,6 +532,7 @@ check_req(#{mode := watch} = R, #st{chan_id = ChId} = St,
         fork_switch ->
             watch_for_channel_change(R, St, C);
         _ ->
+            lager:debug("Other scenario - ignore (~p)", [Scenario]),
             {R, C}
     end;
 check_req(#{mode := tx_hash, tx_hash := TxHash, min_depth := MinDepth} = R,
@@ -597,10 +635,11 @@ report_closed_on_chain(#{ tx_type    := _TxType
 
 maybe_report(RptKey, Info, Rpt, C) when is_function(Rpt) ->
     RptLog = maps:get(rpt_log, C),
-    case aesc_window:keyfind(RptKey, 1, RptLog) of
+    case aesc_window:keyfind(RptKey, #rpt_log_entry.key, RptLog) of
         false ->
             C1 = call_rpt(Rpt, C),
-            C1#{rpt_log => aesc_window:add({RptKey, Info}, RptLog)};
+            LogEntry = #rpt_log_entry{key = RptKey, value = Info},
+            C1#{rpt_log => aesc_window:add(LogEntry, RptLog)};
         _ ->
             C
     end.
@@ -666,15 +705,16 @@ handle_ch_status_changed(ChId, #{ last_block := Last
     lager:debug("channel status changed, Hash=~p, Last=~p", [Hash,Last]),
     {TxLog, C1} = get_txs_since({any_after_block, Last}, Hash, ChId, C),
     lager:debug("New TxLog: ~p", [TxLog]),
-    #{tx_hash := Tx, block_hash := BlockHash} = get_latest_tx(TxLog),
-    lager:debug("Latest Tx = ~p, Hash = ~p", [Tx, BlockHash]),
-    {Status, C2} = get_basic_ch_status_(ChId, BlockHash, C1),
+    {TxHash, #{tx := Tx, block_hash := BlockHash}, C2} =
+        get_latest_tx(TxLog, C1),
+    lager:debug("Latest TxHash = ~p, Hash = ~p", [TxHash, BlockHash]),
+    {Status, C3} = get_basic_ch_status_(ChId, BlockHash, C2),
     lager:debug("ChStatus(~p) = ~p", [BlockHash, Status]),
     %% Assert that this is really a changed channel object
-    true = channel_status_changed(maps:get(vsn, Status), C2),
+    true = channel_status_changed(maps:get(vsn, Status), C3),
     lager:debug("asserted status changed", []),
     Status1 = Status#{tx => Tx},
-    {Status1, C2#{{channel, BlockHash} => Status1}}.
+    {Status1, C3#{{channel, BlockHash} => Status1}}.
 
 get_basic_ch_status_(ChId, #{ top_hash := Hash } = C) ->
     get_basic_ch_status_(ChId, Hash, C).
@@ -732,18 +772,40 @@ log_tx(#{ tx_hash      := TxHash
         , block_origin := _Origin
         , type         := _Type } = Info, #st{tx_log = TxLog} = St) ->
     Key = {TxHash, BlockHash},
-    case aesc_window:keymember(Key, 1, TxLog) of
+    case aesc_window:keymember(Key, #tx_log_entry.key, TxLog) of
         true ->
             St;
         false ->
-            TxLog1 = aesc_window:add({Key, Info}, TxLog),
+            LogEntry = #tx_log_entry{key = Key,
+                                     value = maps:with([block_hash,
+                                                        block_origin,
+                                                        type], Info)},
+            TxLog1 = aesc_window:add(LogEntry, TxLog),
             St#st{tx_log = TxLog1}
     end.
 
-get_latest_tx(Log) ->
-    {{{_TxHash, _BlockHash}, Tx}, _TxLog1} = aesc_window:pop(Log),
-    lager:debug("Tx = ~p", [Tx]),
-    Tx.
+get_latest_tx(Log, C) ->
+    {#tx_log_entry{key = {TxHash, _BlockHash},
+                   value = TxInfo},
+     TxLog1} =
+        aesc_window:pop(Log),
+    lager:debug("TxInfo = ~p", [TxInfo]),
+    case ensure_signed_tx_included(TxHash, TxInfo, C) of
+        {#{tx := undefined}, C1} ->
+            lager:debug("No such signed tx (~p)", [TxHash]),
+            get_latest_tx(TxLog1, C1#{tx_log => TxLog1});
+        {TxInfo1, C1} ->
+            {TxHash, TxInfo1, C1}
+    end.
+
+ensure_signed_tx_included(TxHash, TxInfo, C) ->
+    case maps:is_key(tx, TxInfo) of
+        true ->
+            {TxInfo, C};
+        false ->
+            {SignedTx, C1} = get_signed_tx(TxHash, C),
+            {TxInfo#{tx => SignedTx}, C1}
+    end.
 
 %% Find recent txs. Two different stop conditions:
 %% - {any_after_block, BlockHash}: Stop as soon as a block is found with
@@ -765,12 +827,17 @@ get_txs_since(StopCond, Hash, ChId, C) ->
                 lists:foldl(
                   fun({BlockHash, Txs}, Acc) ->
                           lists:foldl(
-                            fun(TxHash, Acc1) ->
-                                    aesc_window:add(
-                                      { {TxHash, BlockHash},
-                                        #{ tx_hash      => TxHash
-                                         , block_hash => BlockHash
-                                         , block_origin => chain } }, Acc1)
+                            fun(SignedTx, Acc1) ->
+                                    Type = tx_type(SignedTx),
+                                    TxHash = aetx_sign:hash(SignedTx),
+                                    LogEntry =
+                                        #tx_log_entry{
+                                           key = {TxHash, BlockHash},
+                                           value = #{ tx         => SignedTx
+                                                    , block_hash => BlockHash
+                                                    , block_origin => chain
+                                                    , type => Type } },
+                                    aesc_window:add(LogEntry, Acc1)
                             end, Acc, Txs)
                   end, TxLog, Found),
             {TxLog1, C2};
@@ -833,8 +900,8 @@ stop_cond({any_after_block, Hash}, PrevHash, Found) ->
 has_create_tx([]) ->
     false;
 has_create_tx([SignedTx|_] = Found) ->
-    case aetx:specialize_type(aetx_sign:tx(SignedTx)) of
-        {channel_create_tx, _} ->
+    case tx_type(SignedTx) of
+        channel_create_tx ->
             {true, Found};
         _ ->
             false
@@ -936,18 +1003,23 @@ tx_location(TxHash, C) ->
     cached_get({location, TxHash}, C, fun(C1) -> tx_location_(TxHash, C1) end).
 
 tx_location_(TxHash, C) ->
-    L = case aec_chain:find_tx_with_location(TxHash) of
+    {L, Type, SignedTx} =
+        case aec_chain:find_tx_with_location(TxHash) of
             none ->
                 lager:debug("couldn't find tx hash", []),
-                undefined;
-            {mempool, _} ->
+                {undefined, undefined, undefined};
+            {mempool, STx} ->
                 lager:debug("tx still in mempool", []),
-                undefined;
-            {BlockHash, _} ->
+                {undefined, tx_type(STx), STx};
+            {BlockHash, STx} ->
                 lager:debug("tx in Block ~p", [BlockHash]),
-                BlockHash
+                {BlockHash, tx_type(STx), STx}
         end,
-    {L, update_tx_log(TxHash, L, C)}.
+    {L, update_tx_log(TxHash, SignedTx, L, Type, C)}.
+
+tx_type(SignedTx) ->
+    {Type, _} = aetx:specialize_type(aetx_sign:tx(SignedTx)),
+    Type.
 
 in_main_chain(BHash, C) ->
     %% We don't want to use aec_chain_state:hash_is_in_main_chain/1, since we want to
@@ -959,14 +1031,18 @@ in_main_chain_(Hash, C) ->
     Res = aec_chain_state:hash_is_in_main_chain(Hash, TopHash),
     {Res, C1}.
 
-update_tx_log(TxHash, BlockHash, #{tx_log := TxLog} =C)
+update_tx_log(_, undefined, undefined, undefined, C) ->
+    %% don't add a non-existing tx
+    C;
+update_tx_log(TxHash, SignedTx, BlockHash, Type, #{tx_log := TxLog} =C)
   when is_binary(BlockHash) ->
-    C#{tx_log => aesc_window:add(
-                   { {TxHash, BlockHash},
-                     #{ tx_hash      => TxHash
-                      , block_hash   => BlockHash
-                      , block_origin => chain } }, TxLog)};
-update_tx_log(_, _, C) ->
+    LogEntry = #tx_log_entry{key = {TxHash, BlockHash},
+                             value = #{ tx           => SignedTx
+                                      , block_hash   => BlockHash
+                                      , block_origin => chain
+                                      , type         => Type } },
+    C#{tx_log => aesc_window:add(LogEntry, TxLog)};
+update_tx_log(_, _, _, _, C) ->
     C.
 
 top_height(C) ->
diff --git a/apps/aechannel/src/aesc_window.erl b/apps/aechannel/src/aesc_window.erl
index 23bc17b3a2..d89b14f94f 100644
--- a/apps/aechannel/src/aesc_window.erl
+++ b/apps/aechannel/src/aesc_window.erl
@@ -12,12 +12,12 @@
 
 -export([record_fields/1]).
 
--export_type([window/0]).
+-export_type([window/1]).
 
 -define(KEEP, 10).
 
 -type size()   :: non_neg_integer().
--type entry()  :: any().
+-type entry()  :: tuple().
 
 %% This is a bounded buffer, optimized for performance.
 %% A counter, `na`, keeps track of the number of elements
@@ -34,11 +34,14 @@
 -record(w, { na = 0        :: non_neg_integer()
            , nb = 0        :: non_neg_integer()
            , keep = ?KEEP  :: size()
-           , a = []        :: [entry()]
-           , b = []        :: [entry()]
+           , a = []
+           , b = []
            }).
 
--type window() :: #w{}.
+-type window(Entry) :: #w{ a :: [Entry]
+                         , b :: [Entry]
+                         }.
+-type window() :: window(entry()).
 
 %% ==================================================================
 %% Tracing support
@@ -58,17 +61,18 @@ new(Sz) when is_integer(Sz), Sz >= 0 ->
 %% When changing `keep`, we do not modify (e.g. truncate) the data set.
 %% This is for performance reasons, and because we don't strive to keep
 %% the exact size anyway: `keep` is an approximate number.
--spec change_keep(size(), window()) -> window().
+-spec change_keep(size(), window(Entry)) -> window(Entry) when Entry :: entry().
 change_keep(Keep, #w{} = W) when is_integer(Keep), Keep >= 0 ->
     W#w{keep = Keep}.
 
--spec add(entry(), window()) -> window().
+-spec add(Entry, window(Entry)) -> window(Entry) when Entry :: entry().
 add(Item, #w{na = N, a = A, keep = Keep} = W) when N < Keep ->
     W#w{na = N+1, a = [Item|A]};
 add(Item, #w{na = PrevNa, a = A} = W) ->
     W#w{na = 1, a = [Item], nb = PrevNa, b = A}.
 
--spec pop(window()) -> {entry(), window()} | error.
+-spec pop(window(Entry)) -> {Entry, window(Entry)} | error
+  when Entry :: entry().
 pop(#w{a = [], b = []}) ->
     error;
 pop(#w{a = [], b = [H|T], nb = N} = W) ->
@@ -79,13 +83,14 @@ pop(#w{a = [H|T], na = N} = W) ->
 -spec size(window()) -> non_neg_integer().
 size(#w{na = Na, nb = Nb}) -> Na + Nb.
 
--spec to_list(window()) -> [entry()].
+-spec to_list(window(Entry)) -> [Entry] when Entry :: entry().
 to_list(#w{a = A, b = B}) ->
     A ++ B.
 
 %% Like lists:keyfind/3. Finds the most recent match (if any),
 %% since items are essentially stored in LIFO fashion.
--spec keyfind(any(), non_neg_integer(), window()) -> false | entry().
+-spec keyfind(any(), non_neg_integer(), window(Entry)) -> false | Entry
+  when Entry :: entry().
 keyfind(K, Pos, #w{a = A, b = B}) ->
     case lists:keyfind(K, Pos, A) of
         false ->
@@ -104,8 +109,8 @@ keymember(K, Pos, #w{a = A, b = B}) ->
 %% element is not a map are skipped). If a value in the `KVL' is `undefined',
 %% this will match either the value `undefined' or the key being missing.
 %%
--spec info_find([{any(), any()}], non_neg_integer(), window()) ->
-                       false | entry().
+-spec info_find([{any(), any()}], non_neg_integer(), window(Entry)) ->
+                       false | Entry when Entry :: entry().
 info_find(KVL, Pos, #w{a = A, b = B}) when is_list(KVL) ->
     case info_find_(KVL, Pos, A) of
         false ->