diff --git a/src/utils.cc b/src/utils.cc
index e55a47c..7a5ee95 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -10,10 +10,10 @@ using namespace pEp;
 
 namespace pEp {
     namespace Utils {
-        std::vector<::pEp_identity*> to_cxx(const ::identity_list& idl)
+        std::vector<::pEp_identity *> to_cxx(const ::identity_list &idl)
         {
-            vector<pEp_identity*> ret{};
-            for (const ::identity_list* curr = &idl; curr != nullptr; curr = curr->next) {
+            vector<pEp_identity *> ret{};
+            for (const ::identity_list *curr = &idl; curr != nullptr; curr = curr->next) {
                 if (curr->ident) {
                     ret.push_back(curr->ident);
                 }
@@ -21,190 +21,229 @@ namespace pEp {
             return ret;
         }
 
-        string to_string(const ::pEp_identity& ident, bool full, int indent)
+        string to_string(const ::pEp_identity * ident, bool full, int indent)
         {
             stringstream builder;
-            if (full) {
-                builder << endl;
-                builder << std::string(indent, '\t') << "{" << endl;
-                indent++;
-                builder << std::string(indent, '\t') << "address: '"
-                        << (ident.address != nullptr ? ident.address : "NULL") << "'" << endl;
-                builder << std::string(indent, '\t') << "user_id: '"
-                        << (ident.user_id != nullptr ? ident.user_id : "NULL") << "'" << endl;
-                builder << std::string(indent, '\t') << "username: '"
-                        << (ident.username != nullptr ? ident.username : "NULL") << "'" << endl;
-                builder << std::string(indent, '\t') << "fpr: '"
-                        << (ident.fpr != nullptr ? ident.fpr : "NULL") << "'" << endl;
-                builder << std::string(indent, '\t') << "comm_type: " << ident.comm_type << endl;
-                builder << std::string(indent, '\t') << "lang: '" << static_cast<string>(ident.lang)
-                        << "'" << endl;
-                builder << std::string(indent, '\t') << "me: " << ident.me << endl;
-                builder << std::string(indent, '\t') << "major_ver: " << ident.major_ver << endl;
-                builder << std::string(indent, '\t') << "minor_ver: " << ident.minor_ver << endl;
-                builder << std::string(indent, '\t') << "enc_format: " << ident.enc_format << endl;
-                builder << std::string(indent, '\t') << "flags: " << ident.flags << endl;
-                indent--;
-                builder << std::string(indent, '\t') << "}";
+            if (ident != nullptr) {
+                if (full) {
+                    builder << endl;
+                    builder << std::string(indent, '\t') << "{" << endl;
+                    indent++;
+                    builder << std::string(indent, '\t') << "address: '"
+                            << (ident->address != nullptr ? ident->address : "NULL") << "'" << endl;
+                    builder << std::string(indent, '\t') << "user_id: '"
+                            << (ident->user_id != nullptr ? ident->user_id : "NULL") << "'" << endl;
+                    builder << std::string(indent, '\t') << "username: '"
+                            << (ident->username != nullptr ? ident->username : "NULL") << "'"
+                            << endl;
+                    builder << std::string(indent, '\t') << "fpr: '"
+                            << (ident->fpr != nullptr ? ident->fpr : "NULL") << "'" << endl;
+                    builder << std::string(indent, '\t') << "comm_type: " << ident->comm_type << endl;
+                    builder << std::string(indent, '\t') << "lang: '"
+                            << static_cast<string>(ident->lang) << "'" << endl;
+                    builder << std::string(indent, '\t') << "me: " << ident->me << endl;
+                    builder << std::string(indent, '\t') << "major_ver: " << ident->major_ver << endl;
+                    builder << std::string(indent, '\t') << "minor_ver: " << ident->minor_ver << endl;
+                    builder << std::string(indent, '\t') << "enc_format: " << ident->enc_format
+                            << endl;
+                    builder << std::string(indent, '\t') << "flags: " << ident->flags << endl;
+                    indent--;
+                    builder << std::string(indent, '\t') << "}";
+                } else {
+                    builder << std::string(indent, '\t') << "{ '"
+                            << (ident->address != nullptr ? ident->address : "NULL") << "' / '"
+                            << (ident->user_id != nullptr ? ident->user_id : "NULL") << "' / '"
+                            << (ident->username != nullptr ? ident->username : "NULL") << "' / '"
+                            << (ident->fpr != nullptr ? ident->fpr : "NULL") << "' }";
+                }
             } else {
-                builder << std::string(indent, '\t') << "{ '"
-                        << (ident.address != nullptr ? ident.address : "NULL") << "' / '"
-                        << (ident.user_id != nullptr ? ident.user_id : "NULL") << "' / '"
-                        << (ident.username != nullptr ? ident.username : "NULL") << "' / '"
-                        << (ident.fpr != nullptr ? ident.fpr : "NULL") << "' }";
+                builder << "NULL";
             }
 
             return builder.str();
         }
 
-        std::string to_string(const ::bloblist_t& blob, bool full, int indent)
+        std::string to_string(const ::bloblist_t * blob, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "[" << endl;
-            indent++;
-            for (const ::bloblist_t* curr = &blob; curr != nullptr; curr = curr->next) {
-                if (full) {
-                    builder << std::string(indent, '\t') << "{" << endl;
-                    indent++;
-                    builder << std::string(indent, '\t') << "mime_type: '"
-                            << (curr->mime_type != nullptr ? std::string(curr->mime_type) : "NULL")
-                            << "'" << endl;
-                    builder << std::string(indent, '\t') << "filename: '"
-                            << (curr->filename != nullptr ? curr->filename : "NULL") << "'" << endl;
-                    builder << std::string(indent, '\t') << "size: " << curr->size << endl;
-                    builder << std::string(indent, '\t') << "value: '"
-                            << (curr->value != nullptr ? Utils::tldr(std::string(curr->value), 300)
-                                                       : "NULL")
-                            << "'" << endl;
-                    indent--;
-                    builder << std::string(indent, '\t') << "}" << endl;
-                } else {
-                    builder << std::string(indent, '\t');
-                    builder << "{ '"
-                            << (curr->mime_type != nullptr ? std::string(curr->mime_type) : "NULL");
-                    builder << "' / '" << (curr->filename != nullptr ? curr->filename : "NULL");
-                    builder << "' / '" << curr->size << "'";
-                    builder << " }" << endl;
+            if (blob != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "[" << endl;
+                indent++;
+                for (const ::bloblist_t *curr = blob; curr != nullptr; curr = curr->next) {
+                    if (full) {
+                        builder << std::string(indent, '\t') << "{" << endl;
+                        indent++;
+                        builder << std::string(indent, '\t') << "mime_type: '"
+                                << (curr->mime_type != nullptr ? std::string(curr->mime_type) : "NULL")
+                                << "'" << endl;
+                        builder << std::string(indent, '\t') << "filename: '"
+                                << (curr->filename != nullptr ? curr->filename : "NULL") << "'"
+                                << endl;
+                        builder << std::string(indent, '\t') << "size: " << curr->size << endl;
+                        builder << std::string(indent, '\t') << "value: '"
+                                << (curr->value != nullptr
+                                        ? Utils::tldr(std::string(curr->value), 300)
+                                        : "NULL")
+                                << "'" << endl;
+                        indent--;
+                        builder << std::string(indent, '\t') << "}" << endl;
+                    } else {
+                        builder << std::string(indent, '\t');
+                        builder << "{ '"
+                                << (curr->mime_type != nullptr ? std::string(curr->mime_type)
+                                                               : "NULL");
+                        builder << "' / '" << (curr->filename != nullptr ? curr->filename : "NULL");
+                        builder << "' / '" << curr->size << "'";
+                        builder << " }" << endl;
+                    }
                 }
+                indent--;
+                builder << std::string(indent, '\t') << "]" << endl;
+            } else {
+                builder << "NULL";
             }
-            indent--;
-            builder << std::string(indent, '\t') << "]" << endl;
 
             return builder.str();
         }
 
-        std::string to_string(const ::stringpair_list_t& spl, bool full, int indent)
+        std::string to_string(const ::stringpair_list_t * spl, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "[" << endl;
-            indent++;
-            for (const ::stringpair_list_t* curr = &spl; curr != nullptr; curr = curr->next) {
-                builder << std::string(indent, '\t') << "{ '";
-                if (curr->value != nullptr) {
-                    builder << (curr->value->key ? curr->value->key : "NULL");
-                    builder << "' : '";
-                    builder << (curr->value->value ? curr->value->value : "NULL");
+            if (spl != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "[" << endl;
+                indent++;
+                for (const ::stringpair_list_t *curr = spl; curr != nullptr; curr = curr->next) {
+                    builder << std::string(indent, '\t') << "{ '";
+                    if (curr->value != nullptr) {
+                        builder << (curr->value->key ? curr->value->key : "NULL");
+                        builder << "' : '";
+                        builder << (curr->value->value ? curr->value->value : "NULL");
+                    }
+                    builder << "' }" << endl;
                 }
-                builder << "' }" << endl;
+                indent--;
+                builder << std::string(indent, '\t') << "]" << endl;
+            } else {
+                builder << "NULL";
             }
-            indent--;
-            builder << std::string(indent, '\t') << "]" << endl;
 
             return builder.str();
         }
 
-        std::string to_string(const ::message& msg, bool full, int indent)
+        std::string to_string(const ::message * msg, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "{" << endl;
-            indent++;
-            builder << std::string(indent, '\t') << "from: "
-                    << (msg.from != nullptr ? to_string(*msg.from, full, indent) : "NULL") << endl;
-            builder << std::string(indent, '\t')
-                    << "to: " << (msg.to != nullptr ? to_string(*msg.to, full, indent) : "NULL")
-                    << endl;
-            builder << std::string(indent, '\t') << "shortmsg: '"
-                    << (msg.shortmsg != nullptr ? msg.shortmsg : "NULL") << "'" << endl;
-            builder << std::string(indent, '\t') << "longmsg: '"
-                    << (msg.longmsg != nullptr ? msg.longmsg : "NULL") << "'" << endl;
-            builder << std::string(indent, '\t') << "enc_format: " << msg.enc_format << endl;
-            builder << std::string(indent, '\t')
-                    << "dir: " << (msg.dir == 0 ? "incomming" : "outgoing") << endl;
-            builder << std::string(indent, '\t') << "id: '" << (msg.id != nullptr ? msg.id : "NULL")
-                    << "'" << endl;
-            builder << std::string(indent, '\t') << "opt_fields: "
-                    << (msg.opt_fields ? to_string(*msg.opt_fields, full, indent) : "NULL") << endl;
-            builder << std::string(indent, '\t') << "attachments: "
-                    << (msg.attachments ? to_string(*msg.attachments, full, indent) : "NULL")
-                    << endl;
-            indent--;
-            builder << std::string(indent, '\t') << "}" << endl;
+            if (msg != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "{" << endl;
+                indent++;
+                builder << std::string(indent, '\t') << "from: "
+                        << (msg->from != nullptr ? to_string(msg->from, full, indent) : "NULL")
+                        << endl;
+                builder << std::string(indent, '\t') << "to: "
+                        << (msg->to != nullptr ? to_string(msg->to, full, indent) : "NULL") << endl;
+                builder << std::string(indent, '\t') << "shortmsg: '"
+                        << (msg->shortmsg != nullptr ? msg->shortmsg : "NULL") << "'" << endl;
+                builder << std::string(indent, '\t') << "longmsg: '"
+                        << (msg->longmsg != nullptr ? msg->longmsg : "NULL") << "'" << endl;
+                builder << std::string(indent, '\t') << "enc_format: " << msg->enc_format << endl;
+                builder << std::string(indent, '\t')
+                        << "dir: " << (msg->dir == 0 ? "incomming" : "outgoing") << endl;
+                builder << std::string(indent, '\t') << "id: '"
+                        << (msg->id != nullptr ? msg->id : "NULL") << "'" << endl;
+                builder << std::string(indent, '\t') << "opt_fields: "
+                        << (msg->opt_fields ? to_string(msg->opt_fields, full, indent) : "NULL")
+                        << endl;
+                builder << std::string(indent, '\t') << "attachments: "
+                        << (msg->attachments ? to_string(msg->attachments, full, indent) : "NULL")
+                        << endl;
+                indent--;
+                builder << std::string(indent, '\t') << "}" << endl;
+            } else {
+                builder << "NULL";
+            }
 
             return builder.str();
         }
 
-        std::string to_string(const ::identity_list& idl, bool full, int indent)
+        std::string to_string(const ::identity_list * idl, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "[" << endl;
-            indent++;
-            for (const ::identity_list* curr = &idl; curr != nullptr; curr = curr->next) {
-                builder << to_string(*curr->ident, full, indent) << endl;
+            if (idl != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "[" << endl;
+                indent++;
+                for (const ::identity_list *curr = idl; curr != nullptr; curr = curr->next) {
+                    builder << to_string(curr->ident, full, indent) << endl;
+                }
+                indent--;
+                builder << std::string(indent, '\t') << "]";
+            } else {
+                builder << "NULL";
             }
-            indent--;
-            builder << std::string(indent, '\t') << "]";
 
             return builder.str();
         }
 
-        string to_string(const ::pEp_member& member, bool full, int indent)
+        string to_string(const ::pEp_member * member, bool full, int indent)
         {
             stringstream builder;
-            builder << std::string(indent, '\t') << "{" << endl;
-            indent++;
-            builder << std::string(indent, '\t')
-                    << "ident: " << to_string(*member.ident, full, indent) << endl;
-            builder << std::string(indent, '\t') << "joined: " << member.joined << endl;
-            indent--;
-            builder << std::string(indent, '\t') << "}";
+            if (member != nullptr) {
+                builder << std::string(indent, '\t') << "{" << endl;
+                indent++;
+                builder << std::string(indent, '\t')
+                        << "ident: " << to_string(member->ident, full, indent) << endl;
+                builder << std::string(indent, '\t') << "joined: " << member->joined << endl;
+                indent--;
+                builder << std::string(indent, '\t') << "}";
+            } else {
+                builder << "NULL";
+            }
 
             return builder.str();
         }
 
-        string to_string(const ::member_list& mbl, bool full, int indent)
+        string to_string(const ::member_list * mbl, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "[" << endl;
-            indent++;
-            for (const member_list* curr = &mbl; curr != nullptr; curr = curr->next) {
-                builder << to_string(*curr->member, full, indent) << endl;
+            if (mbl != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "[" << endl;
+                indent++;
+                for (const member_list *curr = mbl; curr != nullptr; curr = curr->next) {
+                    builder << to_string(curr->member, full, indent) << endl;
+                }
+                indent--;
+                builder << std::string(indent, '\t') << "]";
+            } else {
+                builder << "NULL";
             }
-            indent--;
-            builder << std::string(indent, '\t') << "]";
 
             return builder.str();
         }
 
-        string to_string(const ::pEp_group& group, bool full, int indent)
+        string to_string(const ::pEp_group * group, bool full, int indent)
         {
             stringstream builder;
-            builder << endl;
-            builder << std::string(indent, '\t') << "{" << endl;
-            indent++;
-            builder << std::string(indent, '\t')
-                    << "group_identity: " << to_string(*group.group_identity, full, indent) << endl;
-            builder << std::string(indent, '\t')
-                    << "manager: " << to_string(*group.manager, full, indent) << endl;
-            builder << std::string(indent, '\t') << "active: " << group.active << endl;
-            builder << std::string(indent, '\t')
-                    << "members: " << to_string(*group.members, full, indent) << endl;
-            indent--;
-            builder << std::string(indent, '\t') << "]";
+            if (group != nullptr) {
+                builder << endl;
+                builder << std::string(indent, '\t') << "{" << endl;
+                indent++;
+                builder << std::string(indent, '\t')
+                        << "group_identity: " << to_string(group->group_identity, full, indent)
+                        << endl;
+                builder << std::string(indent, '\t')
+                        << "manager: " << to_string(group->manager, full, indent) << endl;
+                builder << std::string(indent, '\t') << "active: " << group->active << endl;
+                builder << std::string(indent, '\t')
+                        << "members: " << to_string(group->members, full, indent) << endl;
+                indent--;
+                builder << std::string(indent, '\t') << "]";
+            } else {
+                builder << "NULL";
+            }
 
             return builder.str();
         }
@@ -220,35 +259,35 @@ namespace pEp {
     } // namespace Utils
 } // namespace pEp
 
-std::ostream& operator<<(std::ostream& o, const ::pEp_identity& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::pEp_identity* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::bloblist_t& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::bloblist_t* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::stringpair_list_t& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::stringpair_list_t* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::message& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::message* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::identity_list& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::identity_list* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::pEp_member& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::pEp_member* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::member_list& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::member_list* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
-std::ostream& operator<<(std::ostream& o, const ::pEp_group& pEp_c_dt)
+std::ostream& operator<<(std::ostream& o, const ::pEp_group* pEp_c_dt)
 {
     return o << pEp::Utils::to_string(pEp_c_dt);
 }
\ No newline at end of file
diff --git a/src/utils.hh b/src/utils.hh
index 8ef4713..4ffe221 100644
--- a/src/utils.hh
+++ b/src/utils.hh
@@ -18,14 +18,14 @@ namespace pEp {
         std::vector<::pEp_identity*> to_cxx(const ::identity_list& idl);
 
         // pEpEngine datatypes to string
-        std::string to_string(const ::pEp_identity& ident, bool full = true, int indent = 0);
-        std::string to_string(const ::bloblist_t& ident, bool full = true, int indent = 0);
-        std::string to_string(const ::stringpair_list_t& spl, bool full = true, int indent = 0);
-        std::string to_string(const ::message& msg, bool full = true, int indent = 0);
-        std::string to_string(const ::identity_list& idl, bool full = true, int indent = 0);
-        std::string to_string(const ::pEp_member& member, bool full = true, int indent = 0);
-        std::string to_string(const ::member_list& mbl, bool full = true, int indent = 0);
-        std::string to_string(const ::pEp_group& group, bool full = true, int indent = 0);
+        std::string to_string(const ::pEp_identity* ident, bool full = true, int indent = 0);
+        std::string to_string(const ::bloblist_t* ident, bool full = true, int indent = 0);
+        std::string to_string(const ::stringpair_list_t* spl, bool full = true, int indent = 0);
+        std::string to_string(const ::message* msg, bool full = true, int indent = 0);
+        std::string to_string(const ::identity_list* idl, bool full = true, int indent = 0);
+        std::string to_string(const ::pEp_member* member, bool full = true, int indent = 0);
+        std::string to_string(const ::member_list* mbl, bool full = true, int indent = 0);
+        std::string to_string(const ::pEp_group* group, bool full = true, int indent = 0);
 
         // Misc
         std::string readKey(); // TODO: Move to std_utils
@@ -34,13 +34,13 @@ namespace pEp {
 } // namespace pEp
 
 // ostream inserters
-std::ostream& operator<<(std::ostream& o, const ::pEp_identity& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::bloblist_t& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::stringpair_list_t& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::message& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::identity_list& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::pEp_member& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::member_list& pEp_c_dt);
-std::ostream& operator<<(std::ostream& o, const ::pEp_group& pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::pEp_identity* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::bloblist_t* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::stringpair_list_t* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::message* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::identity_list* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::pEp_member* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::member_list* pEp_c_dt);
+std::ostream& operator<<(std::ostream& o, const ::pEp_group* pEp_c_dt);
 
 #endif // LIBPEPADAPTER_UTILS_HH
\ No newline at end of file