diff --git a/src/gen_cpp_Engine.ysl2 b/src/gen_cpp_Engine.ysl2
index 8a12367..1024f54 100644
--- a/src/gen_cpp_Engine.ysl2
+++ b/src/gen_cpp_Engine.ysl2
@@ -31,6 +31,8 @@ tstylesheet {
         const "returning", "count(parm/creates|parm/returns)";
         const "CretType" choose {
             when "$returning = 0" > void
+            when "$returning = 1" 
+                call "jni_type" with "type", "name(parm[returns|creates]/*[2])";
             when "$returning > 0" > jobject
         }
         const "CretDefault" choose {
@@ -124,13 +126,22 @@ tstylesheet {
         param "name", "name(*[3])";
 
         choose {
-            when "$type = 'stringlist' or $type = 'stringpairlist' or $type = 'identity' or $type = 'identitylist'"
-            ||
-            jobject «$name»_ = NULL;
-            if (_«$name»)
-                «$name»_ = from_«$type»(env, _«$name»);
+            when "$type = 'stringlist' or $type = 'string' or $type = 'sstring' or $type = 'stringpairlist' or $type = 'identity' or $type = 'identitylist'"
+            {
+                const "jnitype" call "jni_type" with "type", "$type";
+                const "from_type" choose {
+                    when "$type = 'sstring'"
+                        > from_string
+                    otherwise
+                        > from_«$type»
+                }
+                ||
+                «$jnitype» «$name»_ = NULL;
+                if (_«$name»)
+                    «$name»_ = «$from_type»(env, _«$name»);
 
-            ||
+                ||
+            }
 
             when "ancestor::namespace/child::enum[@name=$type]" {
                 const "ljtype" call "lcase" with "text","$jtype";
@@ -203,6 +214,10 @@ tstylesheet {
         choose {
             when "ancestor::namespace/child::enum[@name=$type]"
                 | √$type _«$name»;
+            when "$type='sstring'"{
+                | char * _«$name»;
+                | size_t _«$name»_size;
+            }
             otherwise
                 | √$type *_«$name»;
         }
@@ -210,6 +225,7 @@ tstylesheet {
 
     template "parm", mode=call {
         const "dir", "name(*[1])";
+        const "type", "name(*[2])";
         const "name", "name(*[3])";
      
         > , 
@@ -217,12 +233,12 @@ tstylesheet {
         choose {
             when "$dir = 'Cconst'"
                 value "*[3]";
-            when "$dir = 'creates' or $dir = 'returns'" {
+            when "($dir = 'creates' or $dir = 'returns') and $type='sstring'"
+                > &_«$name», &_«$name»_size
+            when "$dir = 'creates' or $dir = 'returns'" 
                 > &_«$name»
-            }
-            otherwise {
+            otherwise 
                 > _«$name»
-            }
         }
     }
 
diff --git a/src/gen_java_Engine.ysl2 b/src/gen_java_Engine.ysl2
index ded1be1..b921ff0 100644
--- a/src/gen_java_Engine.ysl2
+++ b/src/gen_java_Engine.ysl2
@@ -132,7 +132,7 @@ tstylesheet {
 
                 // TODO factorize type conversion with multireturn and gen_java_message.java
 
-                when "count(parm[returns]/stringlist|parm[returns]/string) > 0"
+                when "count(parm[returns][stringlist|string|sstring]) > 0"
                     |> return AbstractEngine.toUTF16(_«@name»(`apply "parm[in]", mode=call;`));
                 when "count(parm[returns]/stringpairlist) > 0"
                     ||
diff --git a/src/pEp.yml2 b/src/pEp.yml2
index beab2e9..30d8b02 100644
--- a/src/pEp.yml2
+++ b/src/pEp.yml2
@@ -203,6 +203,14 @@ namespace pEp {
                 returns identitylist identities
             );
 
+        method get_trustwords(
+                in identity id1,
+                in identity id2,
+                in string lang,
+                returns sstring words,
+                in bool full
+            );
+
         basic string trustwords(identity ident);
         basic identity myself(identity ident);
         basic identity updateIdentity(identity ident);
diff --git a/src/types_c.ysl2 b/src/types_c.ysl2
index 5f5ff29..6b16ed9 100644
--- a/src/types_c.ysl2
+++ b/src/types_c.ysl2
@@ -3,7 +3,7 @@ function "toC" {
 
     choose {
         when "$type='stringlist'" > stringlist_t
-        when "$type='string'" > char
+        when "$type='string' or $type='sstring'" > char
         when "$type='identity'" > pEp_identity
         when "$type='identitylist'" > identity_list
         when "$type='timestamp'" > timestamp
@@ -25,7 +25,7 @@ function "jni_type" {
 
     choose {
         when "../enum[@name=$type]" > jint
-        when "$type = 'string'" > jbyteArray
+        when "$type = 'string' or $type = 'sstring'" > jbyteArray
         when "$type='bool'" > jboolean
         when "$type='int'" > jint
         otherwise > jobject
diff --git a/src/types_java.ysl2 b/src/types_java.ysl2
index e5d0a96..de0029d 100644
--- a/src/types_java.ysl2
+++ b/src/types_java.ysl2
@@ -4,7 +4,7 @@ function "toJava" {
     choose {
         when "$type='bool'" > Boolean
         when "$type='int'" > Integer
-        when "$type='string'" > String
+        when "$type='string' or $type='sstring'" > String
         when "$type='timestamp'" > Date
         when "$type='void'" > void
 
@@ -62,7 +62,7 @@ function "toIntermediate" {
     choose {
         when "$type='bool'" > boolean
         when "$type='int'" > int
-        when "$type='string'" > byte[]
+        when "$type='string' or $type='sstring'" > byte[]
 
         when "$type='bloblist'" > Vector<_Blob>
         when "$type='identity'" > _Identity