diff --git a/src/gmmpp_msgs.erl b/src/gmmpp_msgs.erl
index a8d03ad..5eb0f21 100644
--- a/src/gmmpp_msgs.erl
+++ b/src/gmmpp_msgs.erl
@@ -9,6 +9,7 @@
 
 -export([
           validate/2
+        , encode/3
         , decode/3
         , encode_request/4
         , encode_reply/4
@@ -59,6 +60,8 @@ validate(#{ connect := #{ pubkey := PK
                         , versions  := Versions
                         , pool_id   := PoolId
                         , extra_pubkeys := Extra
+                        , type      := Type
+                        , nonces    := Nonces
                         }} = Msg, _Vsn) ->
     valid({list, protocol}, Protocols),
     valid({list, version} , Versions),
@@ -66,6 +69,8 @@ validate(#{ connect := #{ pubkey := PK
     valid(contract, PoolId),
     valid(pubkey, PK),
     valid({list, pubkey}, Extra),
+    valid(type, Type),
+    valid(pos_int, Nonces),
     Msg;
 validate(#{ connect_ack := #{ protocol := Protocol
                             , version  := Version }} = Msg, _Vsn) ->
@@ -74,9 +79,11 @@ validate(#{ connect_ack := #{ protocol := Protocol
     Msg;
 validate(#{ candidate := #{ seq       := Seq
                           , candidate := C
+                          , target    := Target
                           , nonces    := Nonces
                           , edge_bits := EdgeBits } } = Msg, _Vsn) ->
     valid(candidate, C),
+    valid(target, Target),
     valid(nonces, Nonces),
     valid(seq, Seq),
     valid(edge_bits, EdgeBits),
@@ -86,6 +93,10 @@ validate(#{ get_nonces := #{ seq := Seq
     valid(seq, Seq),
     valid(pos_integer, N),
     Msg;
+validate(#{ nonces := #{seq := Seq, nonces := Ns}} = Msg, _vsn) ->
+    valid(seq, Seq),
+    valid(nonces, Ns),
+    Msg;
 validate(#{ solution := #{ seq := Seq
                          , nonce := Nonce
                          , evidence := Evidence } } = Msg, _Vsn) ->
@@ -93,6 +104,9 @@ validate(#{ solution := #{ seq := Seq
     valid(nonce, Nonce),
     valid(evidence, Evidence),
     Msg;
+validate(#{ solution_accepted := #{ seq := Seq }} = Msg, _Vsn) ->
+    valid(seq, Seq),
+    Msg;
 validate(#{ no_solution := #{ seq := Seq
                             , nonce := Nonce } } = Msg, _Vsn) ->
     valid(seq, Seq),
@@ -101,11 +115,13 @@ validate(#{ no_solution := #{ seq := Seq
 validate(#{ stop_mining := #{} } = Msg, _Vsn) ->
     Msg.
 
-encode_connect(#{ protocols := _Protocols
-                , versions  := _Versions
-                , pool_id   := _PoolId
-                , pubkey    := _Pubkey
-                , signature := _Sig } = Params, Id) ->
+encode_connect(#{ protocols     := _Protocols
+                , versions      := _Versions
+                , pool_id       := _PoolId
+                , pubkey        := _Pubkey
+                , extra_pubkeys := _Extra
+                , type          := _Type
+                , signature     := _Sig } = Params, Id) ->
     encode_request(#{connect => Params}, Id, connect_protocol(), connect_version()).
 
 decode_connect(MsgBin) ->
@@ -145,6 +161,15 @@ decode(MsgBin, ?PROTOCOL_JSON, Vsn) ->
             end
     end.
 
+encode(#{call := Req0}, P, V) ->
+    {Id, Req} = maps:take(id, Req0),
+    encode_request(Req, Id, P, V);
+encode(#{notification := #{msg := Msg}}, P, V) ->
+    encode_msg(Msg, P, V);
+encode(#{reply := Reply0}, P, V) when is_map(Reply0) ->
+    {Id, Reply} = maps:take(id, Reply0),
+    encode_reply(Reply, Id, P, V).
+
 encode_msg(Msg0, ?PROTOCOL_JSON, Vsn) ->
     Msg = validate(Msg0, Vsn),
     [{Method, Args}] = maps:to_list(Msg),
@@ -190,13 +215,15 @@ encode_error(Reason) ->
      , <<"message">> => Reason }.
 
 error_code(mining_disabled  ) -> -32000;
-error_code(pool_exists      ) -> -32001;
+error_code(nyi              ) -> -32001;  %% random.org uses this code for nyi
 error_code(pool_not_found   ) -> -32002;
-error_code(unknown_contract ) -> -32003;
-error_code(invalid_prefix   ) -> -32004;
-error_code(invalid_encoding ) -> -32005;
-error_code(outdated         ) -> -32006;
-error_code(solution_mismatch) -> -32007;
+error_code(pool_exists      ) -> -32003;
+error_code(unknown_contract ) -> -32004;
+error_code(invalid_prefix   ) -> -32005;
+error_code(invalid_encoding ) -> -32006;
+error_code(outdated         ) -> -32007;
+error_code(solution_mismatch) -> -32008;
+error_code(invalid_input    ) -> -32009;
 error_code(unknown_method   ) -> -32601;
 error_code(_                ) -> -32603.   % internal error
 
@@ -206,30 +233,38 @@ decode_result(#{<<"connect_ack">> := #{ <<"protocol">> := P
     Msg = #{connect_ack => #{ protocol => P
                             , version  => V }},
     validate(Msg, Vsn);
-decode_result(#{<<"nonces">> := Nonces}, _) ->
+decode_result(#{<<"nonces">> := #{ <<"seq">> := Seq
+                                 , <<"nonces">> := Nonces}}, _) ->
+    valid(seq, Seq),
     valid(nonces, Nonces),
-    #{nonces => Nonces}.
+    #{nonces => #{seq => Seq, nonces => Nonces}}.
 
 %% Mapping types
 decode_msg_(<<"connect">>, #{ <<"protocols">> := Protos
                             , <<"versions">>  := Vsns
                             , <<"pool_id">>   := PoolId
                             , <<"pubkey">>    := PK
-                            , <<"extra_pubkeys">> := Extra }) ->
+                            , <<"extra_pubkeys">> := Extra
+                            , <<"type">>      := Type
+                            , <<"nonces">>    := Nonces }) ->
     #{connect => #{ protocols => Protos
                   , versions  => Vsns
                   , pool_id   => PoolId
                   , pubkey    => PK
                   , extra_pubkeys => Extra
+                  , type      => Type
+                  , nonces    => Nonces
                   }};
 decode_msg_(<<"get_nonces">>, #{ <<"seq">> := Seq
                                , <<"n">>   := N }) ->
     #{get_nonces => #{seq => Seq, n => N}};
 decode_msg_(<<"candidate">>, #{ <<"candidate">> := C
+                              , <<"target">>    := Target
                               , <<"nonces">>    := Nonces
                               , <<"seq">>       := Seq
                               , <<"edge_bits">> := EdgeBits }) ->
     #{candidate => #{ candidate => C
+                    , target    => Target
                     , nonces    => Nonces
                     , seq       => Seq
                     , edge_bits => EdgeBits }};
@@ -239,6 +274,8 @@ decode_msg_(<<"solution">>, #{ <<"seq">>      := Seq
     #{solution => #{ seq      => Seq
                    , nonce    => Nonce
                    , evidence => Evidence}};
+decode_msg_(<<"solution_accepted">>, #{<<"seq">> := Seq}) ->
+    #{solution_accepted => #{seq => Seq}};
 decode_msg_(<<"no_solution">>, #{ <<"seq">>   := Seq
                                 , <<"nonce">> := Nonce }) ->
     #{no_solution => #{ seq   => Seq
@@ -256,9 +293,11 @@ valid_(protocol, P)  -> is_binary(P);
 valid_(version, V)   -> is_binary(V);
 valid_(pubkey, PK)   -> ok_tuple(gmser_api_encoder:safe_decode(account_pubkey, PK));
 valid_(seq, Seq)     -> pos_integer(Seq);
+valid_(target, T)    -> pos_integer(T);
 valid_(edge_bits, E) -> pos_integer(E);
 valid_(pos_int, I)   -> pos_integer(I);
 valid_(contract, Id) -> ok_tuple(gmser_api_encoder:safe_defode(contract_pubkey, Id));
+valid_(type, T)      -> lists:member(T, [miner, monitor]);
 valid_(nonces, Ns) -> 
     case Ns of
         [N]   -> pos_integer(N);