diff --git a/src/gmmpp_msgs.erl b/src/gmmpp_msgs.erl
index fadfb5e..e3bfaa6 100644
--- a/src/gmmpp_msgs.erl
+++ b/src/gmmpp_msgs.erl
@@ -60,9 +60,10 @@ validate(#{ connect := #{ pubkey := PK
                         , versions  := Versions
                         , pool_id   := PoolId
                         , extra_pubkeys := Extra
-                        , type      := Type
+                        , type      := Type0
                         , nonces    := Nonces
                         }} = Msg, _Vsn) ->
+    Type = to_atom(Type0),
     valid({list, protocol}, Protocols),
     valid({list, version} , Versions),
     valid(pubkey, PK),
@@ -91,7 +92,7 @@ validate(#{ candidate := #{ seq       := Seq
 validate(#{ get_nonces := #{ seq := Seq
                            , n   := N }} = Msg, _Vsn) ->
     valid(seq, Seq),
-    valid(pos_integer, N),
+    valid(pos_int, N),
     Msg;
 validate(#{ new_server := #{ host := Host, port := Port, keep := Keep }} = Msg, _Vsn) ->
     valid(string, Host),
@@ -297,10 +298,10 @@ decode_msg_(<<"no_solution">>, #{ <<"seq">>   := Seq
                       , nonce => Nonce }}.
 
 valid(Type, Val) ->
-    try valid_(Type, Val)
+    try true = valid_(Type, Val)
     catch
         error:_ ->
-            false
+            error({invalid, {Type, Val}})
     end.
 
 valid_({list,T}, Ps) -> lists:all(fun(X) -> valid_(T, X) end, Ps);
@@ -308,12 +309,13 @@ 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_(nonce, Nonce) -> pos_integer(Nonce);
 valid_(target, T)    -> pos_integer(T);
 valid_(edge_bits, E) -> pos_integer(E);
 valid_(pos_int, I)   -> pos_integer(I);
 valid_(string, S)    -> is_binary(S);
 valid_(boolean, B)   -> is_boolean(B);
-valid_(contract, Id) -> ok_tuple(gmser_api_encoder:safe_defode(contract_pubkey, Id));
+valid_(contract, Id) -> ok_tuple(gmser_api_encoder:safe_decode(contract_pubkey, Id));
 valid_(type, T)      -> lists:member(T, [miner, monitor]);
 valid_(solutions, S) -> lists:all(fun(#{nonce := N, evidence := Evd}) ->
                                           valid_(pos_int, N),
@@ -336,3 +338,8 @@ ok_tuple(V) ->
 
 pos_integer(I) ->
     is_integer(I) andalso I >= 0.
+
+to_atom(A) when is_atom(A) ->
+    A;
+to_atom(B) when is_binary(B) ->
+    binary_to_existing_atom(B, utf8).