diff --git a/src/gen_cpp_Engine.ysl2 b/src/gen_cpp_Engine.ysl2
index eef8111..9f50823 100644
--- a/src/gen_cpp_Engine.ysl2
+++ b/src/gen_cpp_Engine.ysl2
@@ -17,6 +17,7 @@ tstylesheet {
         #include "foundation_pEp_jniadapter_«@name».h"
         #include "throw_pEp_exception.hh"
         #include "jniutils.hh"
+        #include <pEp/passphrase_cache.hh>
 
         using pEp::Adapter::session;
         using namespace pEp::JNIAdapter;
@@ -62,7 +63,20 @@ tstylesheet {
         apply "parm[creates|returns]", mode=out;
         ||
 
-            PEP_STATUS status = ::«@name»(session()`apply "parm", mode=call`);
+        ||
+        choose {
+            when "@cached = 'true'" {
+            ||
+                pEpLog("cached passphrase");
+                PEP_STATUS status = cache.api(::«@name»,session()`apply "parm", mode=call`);
+            ||
+            } otherwise {
+            ||
+                PEP_STATUS status = ::«@name»(session()`apply "parm", mode=call`);
+            ||
+            }
+        }
+        ||
             if ((status > PEP_STATUS_OK && status < PEP_UNENCRYPTED) |`> |`
                     status < PEP_STATUS_OK |`> |`
                     status >= PEP_TRUSTWORD_NOT_FOUND) {
@@ -237,6 +251,8 @@ tstylesheet {
                 | bool _«$name» = (bool) «$name»;
             when "$type='int'"
                 | int _«$name» = (int) «$name»;
+            when "$type='string'"
+                | const char *_«$name» = to_string(env, «$name»);
             otherwise
                 | √$type *_«$name» = to_«$type»(env, «$name»);
         }
diff --git a/src/pEp.yml2 b/src/pEp.yml2
index e9d0309..603f4fe 100644
--- a/src/pEp.yml2
+++ b/src/pEp.yml2
@@ -85,32 +85,32 @@ namespace pEp {
     };
 
     interface Engine {
-        method encrypt_message(
+        method cached=true encrypt_message(
                 in message src,
                 in stringlist extra,
                 creates message dst,
                 in EncFormat format,
-                Cconst PEP_encrypt_flags flags "0"
+                Cconst PEP_encrypt_flags flags "(PEP_encrypt_flags_t)0"
             );
 
-        method encrypt_message_and_add_priv_key(
+        method cached=true encrypt_message_and_add_priv_key(
                 in message src,
                 creates message dst,
                 in string fpr,
                 Cconst PEP_enc_format encformat "PEP_enc_PEP",
-                Cconst PEP_encrypt_flags flags "0"
+                Cconst PEP_encrypt_flags flags "(PEP_encrypt_flags_t)0"
             );
 
-        method encrypt_message_for_self(
+        method cached=true encrypt_message_for_self(
                 in identity target,
                 in message src,
                 in stringlist extra,
                 creates message dst,
                 Cconst PEP_enc_format encformat "PEP_enc_PEP",
-                Cconst PEP_encrypt_flags flags "0"
+                Cconst PEP_encrypt_flags flags "(PEP_encrypt_flags_t)0"
             );
 
-        method decrypt_message(
+        method cached=true decrypt_message(
                 inout message src,
                 creates message dst,
                 inout stringlist keylist,
@@ -150,7 +150,8 @@ namespace pEp {
                 returns stringlist blacklist
             );
 
-        method own_message_private_key_details(
+        // TODO: WTF is...
+        method cached=true own_message_private_key_details(
                 in message msg,
                 returns identity ident 
             );