diff --git a/.hgignore b/.hgignore
index e81e918..dbbd3a4 100644
--- a/.hgignore
+++ b/.hgignore
@@ -3,44 +3,52 @@ syntax: glob
 # ignore all of them
 
 *.class
-*.jar
-*.swp
-*.o
-*.a
-*.dylib
-*.so
-*.orig
-*~
-.DS_Store
-*.db
 *.log
+.DS_Store
 
-# ignore generated files
+# ignore config files
+local.conf
+
+# ignore build and dist dirs
+build/*
+dist/*
 
-org_pEp_*.h
-org_pEp_*.cc
-pEp_*.h
-pEp_*.cc
-org/pEp/jniadapter/pEp*.java
-foundation_pEp_*.h
-foundation_pEp_*.cc
-foundation/pEp/jniadapter/pEp*.java
+# ignore generated files
+status_list.yml2
+passphrase_status_list.yml2
 
-pEp/jniadapter/pEp*.java
+foundation_pEp_jniadapter__Blob.h
+foundation_pEp_jniadapter_AbstractEngine.h
+foundation_pEp_jniadapter_Engine.*
+foundation_pEp_jniadapter_Message.*
+foundation_pEp_jniadapter_Identity.h
 throw_pEp_exception.*
+src/java/foundation/pEp/jniadapter/exceptions/*.java
+
+CipherSuite.java
 Color.java
+DecryptFlags.java
 Engine.java
+EngineInterface.java
+IdentityFlags.java
 Message.java
-DecryptFlags.java
+MessageInterface.java
 Rating.java
 Status.java
 SyncHandshakeResult.java
-IdentityFlags.java
 SyncHandshakeSignal.java
-CipherSuite.java
+PassphraseType.java
+
+# ignore pep-homes
+test/resources/per-user-dirs/alice/.pEp
+test/resources/per-user-dirs/bob/.pEp
+test/resources/per-user-dirs/carol/.pEp
+
+# FsMsgQueue data
+test/resources/fsmsgqueue-test/Alice
+test/resources/fsmsgqueue-test/Bob
+test/resources/fsmsgqueue-test/Carol
 
-passphrase_status_list.yml2
-status_list.yml2
 
 ndk*/
 # ignore vim workspace
@@ -78,15 +86,12 @@ android/gradlew.bat
 androidTests/gradle/wrapper/gradle-wrapper.properties
 androidTests/gradlew
 androidTests/gradlew.bat
-src/org.tar.gz
-src/local.conf
+org.tar.gz
 
 *.iml
 
 syntax: regexp
 android/external/[^.]*
 
-local.conf
-src/local.conf
 # Default ignored files
 .idea/
diff --git a/Makefile b/Makefile
index 45acece..4acf87e 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 # This file may be used under the terms of the GNU General Public License version 3
 # see LICENSE.txt
 
-.PHONY: all src test clean doxy-all doxy-cxx doxy-java doxy-clean
+.PHONY: all src test clean doxy-all doxy-cxx doxy-java doxy-clean install uninstall
 
 all: src
 
@@ -29,3 +29,10 @@ doxy-java: src
 doxy-clean:
 	rm -rf doc/doxygen/cxx
 	rm -rf doc/doxygen/java
+
+install:
+	$(MAKE) -C src install
+
+uninstall:
+	$(MAKE) -C src uninstall
+
diff --git a/Makefile.conf b/Makefile.conf
index e9f2627..2166eac 100644
--- a/Makefile.conf
+++ b/Makefile.conf
@@ -9,14 +9,15 @@ PLATFORM:=$(shell uname | tr A-Z a-z)
 # DEV ENV PATHS & CFG
 # The dev environment paths and configs are set to a default value which can be overridden by ./local.conf and overridden again by <subdir>/local.conf
 ######### Build Config Defaults #########
-DEBUG=1
-YML2_PATH=$(HOME)/yml2
+DEBUG=0
+PREFIX=$(HOME)
+YML2_PATH=$(PREFIX)/src/yml2
 YML2_PROC=$(YML2_PATH)/yml2proc $(YML2_OPTS)
 YML2_OPTS=--encoding=utf8
-ENGINE_LIB_PATH=$(HOME)/lib
-ENGINE_INC_PATH=$(HOME)/include
-AD_LIB_PATH=$(HOME)/lib
-AD_INC_PATH=$(HOME)/include
+ENGINE_LIB_PATH=$(PREFIX)/lib
+ENGINE_INC_PATH=$(PREFIX)/include
+AD_LIB_PATH=$(PREFIX)/lib
+AD_INC_PATH=$(PREFIX)/include
 
 ### Guessing JAVA_HOME
 ifeq ($(PLATFORM),linux)
@@ -24,6 +25,12 @@ ifeq ($(PLATFORM),linux)
 endif
 
 
+# Old versions of a Java distribution have a `javah` binary, new versions do not. This checks whether or not `javah` can be found in the Java distribution found in the directory `$JAVA_HOME`.
+DUMMY:=$(shell which $(JAVA_HOME)/bin/javah)
+ifeq ($(.SHELLSTATUS),0)
+    OLD_JAVA=true
+endif
+
 ######### Overrides from the config file(s) #########
 ifneq ("$(wildcard $(HERE)local.conf)","")
     $(info including: $(HERE)local.conf)
@@ -32,19 +39,17 @@ else
     $(info Optional build config not found: $(HERE)local.conf)
 endif
 
-ifneq ("$(wildcard $(HERE)src/local.conf)","")
-    $(info including: $(HERE)src/local.conf)
-    -include $(HERE)src/local.conf
-else
-    $(info Optional build config not found: $(HERE)src/local.conf)
-endif
-
 ### Apply config
 ENGINE_LIB=-L$(ENGINE_LIB_PATH)
 ENGINE_INC=-I$(ENGINE_INC_PATH)
 AD_LIB=-L$(AD_LIB_PATH)
 AD_INC=-I$(AD_INC_PATH)
 
+ifndef JAVA_HOME
+    $(error JAVA_HOME is not set!)
+endif
+
+JAVA_BIN_DIR=$(JAVA_HOME)/bin
 
 ######### C and C++ #########
 CXXFLAGS+=-O0 -std=c++11 -fpermissive -fPIC -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/$(PLATFORM) $(AD_INC) $(ENGINE_INC)
diff --git a/android/build.gradle b/android/build.gradle
index f058512..c5f0960 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -94,7 +94,7 @@ android {
     // call source generation makefile target
     task genSources(type:Exec, dependsOn: 'genpEpEngineAsn1Sources') {
         workingDir '../src'
-        commandLine 'make', "-j${threadsToUse}", 'pEp.jar'
+        commandLine 'make', "-j${threadsToUse}", 'lib-java'
     }
 
     task genpEpEngineSyncSources(type:Exec) {
diff --git a/android/jni/Android.mk b/android/jni/Android.mk
index 24a635b..abc0209 100644
--- a/android/jni/Android.mk
+++ b/android/jni/Android.mk
@@ -47,14 +47,14 @@ LOCAL_STATIC_LIBRARIES := pEpEngine libetpan libiconv libuuid pEpAdapter libsequ
 LOCAL_CPP_FEATURES += exceptions
 LOCAL_CPPFLAGS += -std=c++11 -DANDROID_STL=c++_shared -DHAVE_PTHREADS -DDISABLE_SYNC -fuse-ld=lld
 LOCAL_SRC_FILES  := \
-		  ../../src/foundation_pEp_jniadapter_AbstractEngine.cc \
-		  ../../src/foundation_pEp_jniadapter_Engine.cc \
-		  ../../src/foundation_pEp_jniadapter_Message.cc \
-		  ../../src/foundation_pEp_jniadapter__Blob.cc \
-		  ../../src/throw_pEp_exception.cc \
-		  ../../src/basic_api.cc \
-		  ../../src/identity_api.cc \
-		  ../../src/jniutils.cc
+		  ../../src/cxx/foundation_pEp_jniadapter_AbstractEngine.cc \
+		  ../../src/cxx/foundation_pEp_jniadapter_Engine.cc \
+		  ../../src/cxx/foundation_pEp_jniadapter_Message.cc \
+		  ../../src/cxx/foundation_pEp_jniadapter__Blob.cc \
+		  ../../src/cxx/throw_pEp_exception.cc \
+		  ../../src/cxx/basic_api.cc \
+		  ../../src/cxx/identity_api.cc \
+		  ../../src/cxx/jniutils.cc
 
 LOCAL_C_INCLUDES += $(GPGBUILD)/$(TARGET_ARCH_ABI)/include
 LOCAL_C_INCLUDES += $(LIB_PEP_ADAPTER_PATH)/build-android/include $(SRC_PATH)/libpEpAdapter
diff --git a/android/src/foundation/pEp/jniadapter/AndroidHelper.java b/android/src/foundation/pEp/jniadapter/AndroidHelper.java
index f9e71b8..eaa52b0 100644
--- a/android/src/foundation/pEp/jniadapter/AndroidHelper.java
+++ b/android/src/foundation/pEp/jniadapter/AndroidHelper.java
@@ -10,6 +10,8 @@ import java.io.*;
 import java.lang.reflect.Method;
 import java.util.Scanner;
 
+import foundation.pEp.jniadapter.exceptions.pEpException;
+
 public class AndroidHelper {
     static {
         System.loadLibrary("pEpJNIAndroidHelper");
diff --git a/local.conf.example b/local.conf.example
index 8de0aa8..310de4b 100644
--- a/local.conf.example
+++ b/local.conf.example
@@ -2,23 +2,28 @@
 # you might not need this file, but if the defaults dont work for you
 # You can override them here.
 # Tweak the values to your needs and rename it to local.conf
+# These example values here reflect the defaults
+
+############ Install ###########
+# PREFIX=$(HOME)
 
 ######### C++ Compiler #########
 # Should work with clang and g++
 # CXX=g++
-# DEBUG=1       # DEBUG Build (Default)
-# DEBUG=0       # RELEASE Build
+# DEBUG=0       # RELEASE Build / set to 1 for DEBUG build
 
-######### JAVA #########
+############ JAVA ##############
 # JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_231.jdk/Contents/Home
 
-######### YML2 #########
-# YML2_PATH=$(HOME)/code/yml2
+############ YML2 ##############
+# YML2_PATH=$(HOME)/src/yml2
+
+########### Engine #############
+# ENGINE_LIB_PATH=$(PREFIX)/lib
+# ENGINE_INC_PATH=$(PREFIX)/include
+
+########## libAdapter ##########
+# AD_LIB_PATH=$(PREFIX)/lib
+# AD_INC_PATH=$(PREFIX)/include
 
-######### Engine #########
-# ENGINE_LIB_PATH=$(HOME)/local/lib
-# ENGINE_INC_PATH=$(HOME)/local/include
 
-######### libAdapter #########
-# AD_LIB_PATH=$(HOME)/local/lib
-# AD_INC_PATH=$(HOME)/local/include
diff --git a/src/Makefile b/src/Makefile
index e1a412b..325fee2 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -5,6 +5,30 @@
 
 include ../Makefile.conf
 
+# Names of the java and c++ libs to be built
+LIB_JAVA_NAME=pEp.jar
+LIB_CXX_NAME=libpEpJNI
+DIST_DIR=../dist/
+
+
+LIB_CXX_STATIC_NAME=$(addsuffix .a,$(LIB_CXX_NAME))
+ifeq ($(PLATFORM),linux)
+    LIB_CXX_DYN_NAME=$(addsuffix .so,$(LIB_CXX_NAME))
+else ifeq ($(PLATFORM),darwin)
+    LIB_CXX_DYN_NAME=$(addsuffix .dylib,$(LIB_CXX_NAME))
+else
+    $(error I dont know how to build for $(PLATFORM).)
+endif
+
+LIB_JAVA=$(DIST_DIR)/$(LIB_JAVA_NAME)
+LIB_CXX_STATIC=$(DIST_DIR)/$(LIB_CXX_STATIC_NAME)
+LIB_CXX_DYN=$(DIST_DIR)/$(LIB_CXX_DYN_NAME)
+
+$(info ------------------ DIST FILES ---------------------)
+$(info LIB_JAVA:        $(LIB_JAVA))
+$(info LIB_CXX_STATIC:  $(LIB_CXX_STATIC))
+$(info LIB_CXX_DYN:     $(LIB_CXX_DYN))
+$(info ------------------ BUILD INFO ---------------------)
 $(info PLATFORM:        $(PLATFORM))
 $(info DEBUG:           $(DEBUG))
 $(info CXX:             $(CXX))
@@ -17,133 +41,151 @@ $(info YML2_PATH:       $(YML2_PATH))
 $(info CXXFLAGS:        $(CXXFLAGS))
 $(info LDFLAGS:         $(LDFLAGS))
 $(info LDLIBS:          $(LDLIBS))
+$(info ---------------------------------------------------)
 
-ifndef JAVA_HOME
-    $(error JAVA_HOME is not set!)
-endif
+# Dirs
+# relative to "src/"
+BUILD_ROOT=../build/
+CXX_DIR=cxx/
+JAVA_DIR=java/
+JAVA_PKG_BASENAME=foundation/pEp/jniadapter/
 
-JP=$(JAVA_HOME)/bin
+JAVA_PKG_ROOT=$(JAVA_DIR)/$(JAVA_PKG_BASENAME)
+JAVA_BUILD_ROOT=$(BUILD_ROOT)/$(JAVA_DIR)
+OBJ_DIR=$(BUILD_ROOT)/$(CXX_DIR)
 
-# Old versions of a Java distribution have a `javah` binary, new versions do not. This checks whether or not `javah` can be found in the Java distribution found in the directory `$JAVA_HOME`.
-NOT_USED:=$(shell which $(JAVA_HOME)/bin/javah)
-ifeq ($(.SHELLSTATUS),0)
-    OLD_JAVA=placeholder
-endif
 
-LIBRARY=libpEpJNI.a
-JAR=pEp.jar
+# for "make clean" only
+GENERATED_JAVA=\
+	$(JAVA_PKG_ROOT)/Engine.java \
+	$(JAVA_PKG_ROOT)/Message.java \
+	$(JAVA_PKG_ROOT)/CipherSuite.java \
+	$(JAVA_PKG_ROOT)/Color.java \
+	$(JAVA_PKG_ROOT)/DecryptFlags.java \
+	$(JAVA_PKG_ROOT)/IdentityFlags.java \
+	$(JAVA_PKG_ROOT)/Rating.java \
+	$(JAVA_PKG_ROOT)/SyncHandshakeResult.java \
+	$(JAVA_PKG_ROOT)/SyncHandshakeSignal.java \
+	$(JAVA_PKG_ROOT)/PassphraseType.java \
+	$(JAVA_PKG_ROOT)/interfaces/EngineInterface.java \
+ 	$(JAVA_PKG_ROOT)/interfaces/MessageInterface.java \
+ 	$(JAVA_PKG_ROOT)/exceptions/*.java
 
-ifeq ($(PLATFORM),linux)
-    SHARED=libpEpJNI.so
-else ifeq ($(PLATFORM),darwin)
-    SHARED=libpEpJNI.dylib
-else
-    $(error I dont know how to build for $(PLATFORM).)
-endif
+# files to compile which will be be generated
+GENERATED_CC=\
+	$(CXX_DIR)/foundation_pEp_jniadapter_Engine.cc \
+	$(CXX_DIR)/foundation_pEp_jniadapter_Message.cc \
+	$(CXX_DIR)/throw_pEp_exception.cc
+
+# for "make clean" only
+GENERATED_HH=\
+	$(CXX_DIR)/throw_pEp_exception.hh
+
+# Generated JNI headers (javac -h)
+JNI_GENERATED_HH=\
+	$(CXX_DIR)/foundation_pEp_jniadapter_AbstractEngine.h \
+    $(CXX_DIR)/foundation_pEp_jniadapter__Blob.h \
+    $(CXX_DIR)/foundation_pEp_jniadapter_Engine.h \
+    $(CXX_DIR)/foundation_pEp_jniadapter_Identity.h \
+    $(CXX_DIR)/foundation_pEp_jniadapter_Message.h
+
+# Auto dependencies using gcc/clang
+CXXFLAGS+= -MMD -MP
+
+SOURCES=$(wildcard $(CXX_DIR)/*.cc)
+SOURCES+=$(GENERATED_CC)
+tmp=$(SOURCES:.cc=.o)
+OBJECTS=$(addprefix $(BUILD_ROOT), $(tmp))
+DEPENDS=$(OBJECTS:.o=.d)
 
-JAVA_SOURCES=foundation/pEp/jniadapter/AbstractEngine.java \
-    foundation/pEp/jniadapter/Blob.java \
-    foundation/pEp/jniadapter/CommType.java \
-    foundation/pEp/jniadapter/Identity.java \
-    foundation/pEp/jniadapter/Pair.java \
-    foundation/pEp/jniadapter/Sync.java \
-    foundation/pEp/jniadapter/_Blob.java \
-    foundation/pEp/jniadapter/_Identity.java \
-    foundation/pEp/jniadapter/pEpException.java \
-    foundation/pEp/jniadapter/Message.java \
-    foundation/pEp/jniadapter/Engine.java \
-
-C_SOURCES=foundation_pEp_jniadapter_Engine.cc \
-    foundation_pEp_jniadapter_Engine.h \
-    foundation_pEp_jniadapter_Message.cc \
-    foundation_pEp_jniadapter_Message.h \
-    throw_pEp_exception.cc \
-    throw_pEp_exception.hh \
-    foundation_pEp_jniadapter_AbstractEngine.h \
-    foundation_pEp_jniadapter__Blob.cc \
-    foundation_pEp_jniadapter__Blob.h
-
-PEP_HEADER:=$(shell $(CXX) $(CXXFLAGS) -E -M get_header.cc | grep -oe '[^[:space:]]*pEpEngine\.h' | head -1)
-
-
-.PHONY: all
-all: $(JAR) $(SHARED)
-
-$(JAR): status_list.yml2 passphrase_status_list.yml2 $(JAVA_SOURCES) $(C_SOURCES)
-	$(JP)/javac foundation/pEp/jniadapter/*.java
-	$(JP)/jar cf $@ foundation/pEp/jniadapter/*.class
-
-BLUBB=foundation_pEp_jniadapter_AbstractEngine.h foundation_pEp_jniadapter_Engine.h foundation_pEp_jniadapter_Message.h foundation_pEp_jniadapter__Blob.h
-$(BLUBB): foundation_pEp_jniadapter_%.h: foundation/pEp/jniadapter/%.java
+-include $(DEPENDS)
+VPATH = $(CXX_DIR)/
+
+.PHONY: all lib-java lib-cxx compile-java compile-cxx gen-jni-headers codegen clean create-dirs remove-dirs install uninstall
+
+$(info SOURCES: $(SOURCES))
+$(info OBJECTS: $(OBJECTS))
+$(info DEPENDS: $(DEPENDS))
+
+all: lib-java lib-cxx
+
+# Build only java lib
+lib-java: $(LIB_JAVA)
+
+# Build only c++ static/shared lib
+lib-cxx: $(LIB_CXX_DYN) $(LIB_CXX_STATIC)
+
+# ---------------- Link -----------------
+$(LIB_JAVA): compile-java
+	$(JAVA_BIN_DIR)/jar cf $@ -C $(JAVA_BUILD_ROOT) foundation
+
+$(LIB_CXX_DYN): compile-cxx
+	$(CXX) $(OBJ_DIR)*.o $(LDFLAGS) $(LDLIBS) -o $@
+
+$(LIB_CXX_STATIC): compile-cxx
+	$(AR) -r $@ $(OBJ_DIR)*.o
+
+
+# -------------- Compile -----------------
+compile-java: create-dirs codegen
+	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javac -d ../$(JAVA_BUILD_ROOT) $(JAVA_PKG_BASENAME)/*.java
+	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javac -d ../$(JAVA_BUILD_ROOT) $(JAVA_PKG_BASENAME)/exceptions/*.java
+	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javac -d ../$(JAVA_BUILD_ROOT) $(JAVA_PKG_BASENAME)/interfaces/*.java
+
+
+compile-cxx: create-dirs gen-jni-headers $(OBJECTS)
+
+$(OBJECTS): $(BUILD_ROOT)%.o: %.cc
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+
+# --------- Generate JNI headers ----------
+gen-jni-headers: codegen $(JNI_GENERATED_HH)
+
+$(JNI_GENERATED_HH):
 ifdef OLD_JAVA
-	$(JP)/javah $(subst /,.,$(subst .java,,$<))
+	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javah -d ../$(JAVA_BUILD_ROOT) $(subst /,.,$(subst .java,,$<))
 else
-	$(JP)/javac -h . $<
+	cd $(JAVA_DIR);$(JAVA_BIN_DIR)/javac -d ../$(JAVA_BUILD_ROOT) -h ../$(CXX_DIR)/ $(JAVA_PKG_BASENAME)/*.java
 endif
 
-foundation_pEp_jniadapter_AbstractEngine.o: %.o: %.cc %.h throw_pEp_exception.hh jniutils.hh
-	$(CXX) $(CXXFLAGS) -c $< -o $@
 
-foundation_pEp_jniadapter_Engine.o foundation_pEp_jniadapter_Message.o foundation_pEp_jniadapter__Blob.o : %.o: %.cc %.h
-	$(CXX) $(CXXFLAGS) -c $< -o $@
+# ------------- YML2 CodeGen --------------
+codegen:
+	$(MAKE) -C codegen
+
+# ------------- Housekeeping ---------------
+create-dirs:
+	$(MAKE) -C codegen create-dirs
+	mkdir -p $(JAVA_BUILD_ROOT)/$(JAVA_PKG_BASENAME)
+	mkdir -p $(JAVA_BUILD_ROOT)/$(JAVA_PKG_BASENAME)/exceptions
+	mkdir -p $(OBJ_DIR)
+	mkdir -p $(DIST_DIR)
+	mkdir -p $(JAVA_PKG_ROOT)/exceptions
+
+#rm -rf is too dangerous for vars
+remove-dirs:
+	$(MAKE) -C codegen remove-dirs
+	rm -rf ../build
+	rm -rf ../dist
+
+clean: remove-dirs
+	$(MAKE) -C codegen clean
+	rm -f $(GENERATED_JAVA)
+	rm -f $(GENERATED_CC)
+	rm -f $(GENERATED_HH)
+	rm -f $(JNI_GENERATED_HH)
+	rm -f $(DEPENDS)
+	rm -f $(OBJECTS)
+
+install: $(LIB_JAVA) $(LIB_CXX_STATIC) $(LIB_CXX_DYN)
+	mkdir -p $(PREFIX)/lib
+	cp -v $(LIB_JAVA) 		$(PREFIX)/lib/
+	cp -v $(LIB_CXX_STATIC) $(PREFIX)/lib/
+	cp -v $(LIB_CXX_DYN) 	$(PREFIX)/lib/
+
+uninstall:
+	cd $(PREFIX)/lib && rm -vf $(LIB_JAVA_NAME)
+	cd $(PREFIX)/lib && rm -vf $(LIB_CXX_STATIC_NAME)
+	cd $(PREFIX)/lib && rm -vf $(LIB_CXX_DYN_NAME)
 
-$(LIBRARY): foundation_pEp_jniadapter_AbstractEngine.o foundation_pEp_jniadapter_Engine.o foundation_pEp_jniadapter_Message.o throw_pEp_exception.o jniutils.o basic_api.o foundation_pEp_jniadapter__Blob.o
-	ar -r $@ *.o
-
-$(SHARED): $(LIBRARY)
-	$(CXX) *.o $(LDFLAGS) $(LDLIBS) -o $@
-
-status_list.yml2: pEp.yml2
-	bash ../utils/extract_pEp_status_codes_from_engine.sh "$(PEP_HEADER)" $@
-
-passphrase_status_list.yml2: status_list.yml2
-	grep passphrase $< > $@
-
-foundation/pEp/jniadapter/pEpException.java: pEp.yml2 gen_java_exceptions.ysl2 pEp.yml2
-	$(YML2_PROC) -y gen_java_exceptions.ysl2 $< -o $@
-
-foundation/pEp/jniadapter/Message.java: pEp.yml2 gen_java_Message.ysl2 types_java.ysl2
-	$(YML2_PROC) -y gen_java_Message.ysl2 $<
-
-foundation/pEp/jniadapter/Engine.java: pEp.yml2 gen_java_Engine.ysl2 types_java.ysl2
-	$(YML2_PROC) -y gen_java_Engine.ysl2 $<
-
-foundation_pEp_jniadapter_Message.cc: pEp.yml2 gen_cpp_Message.ysl2 types_c.ysl2
-	$(YML2_PROC) -y gen_cpp_Message.ysl2 $<
-
-foundation_pEp_jniadapter_Engine.cc: pEp.yml2 gen_cpp_Engine.ysl2 types_c.ysl2
-	$(YML2_PROC) -y gen_cpp_Engine.ysl2 $<
-
-throw_pEp_exception.cc throw_pEp_exception.hh: pEp.yml2 gen_throw_pEp_exception.ysl2 textutils.ysl2
-	$(YML2_PROC) -y gen_throw_pEp_exception.ysl2 $< -o throw_pEp_exception.cc
-
-throw_pEp_exception.o: throw_pEp_exception.cc throw_pEp_exception.hh
-
-basic_api.o: basic_api.cc jniutils.hh throw_pEp_exception.hh
-
-.PHONY: clean
-clean:
-	rm -f $(JAR) $(LIBRARY) $(SHARED)
-	rm -f *.so
-	rm -f *.dylib
-	rm -f *.o
-	rm -f *.class
-	rm -f *.xml *.xsl
-	rm -f foundation_pEp_jniadapter_*.h
-	rm -f foundation/pEp/jniadapter/*.class
-	rm -f foundation/pEp/jniadapter/pEp*.java
-	rm -f foundation/pEp/jniadapter/Engine.java
-	rm -f foundation/pEp/jniadapter/Message.java
-	rm -f foundation/pEp/jniadapter/Color.java
-	rm -f foundation/pEp/jniadapter/DecryptFlags.java
-	rm -f foundation/pEp/jniadapter/IdentityFlags.java
-	rm -f foundation/pEp/jniadapter/Rating.java
-	rm -f foundation/pEp/jniadapter/Status.java
-	rm -f foundation/pEp/jniadapter/SyncHandshakeResult.java
-	rm -f foundation/pEp/jniadapter/SyncHandshakeSignal.java
-	rm -f foundation/pEp/jniadapter/CipherSuite.java
-	rm -f foundation/pEp/jniadapter/PassphraseType.java
-	rm -f throw_pEp_exception.*
-	rm -f foundation_pEp_jniadapter_Message.cc foundation_pEp_jniadapter_Engine.cc
-	rm -f status_list.yml2
-	rm -f passphrase_status_list.yml2
diff --git a/src/codegen/Makefile b/src/codegen/Makefile
new file mode 100644
index 0000000..556aae4
--- /dev/null
+++ b/src/codegen/Makefile
@@ -0,0 +1,60 @@
+# Copyright 2018, pEp Foundation
+# This file is part of pEp JNI Adapter
+# This file may be used under the terms of the GNU General Public License version 3
+# see LICENSE.txt
+
+include ../../Makefile.conf
+
+MARKER_DIR=../../build/marker/
+
+PEP_HEADER:=$(shell $(CXX) $(CXXFLAGS) -E -M ../cxx/get_header.cc | grep -oe '[^[:space:]]*pEpEngine\.h' | head -1)
+
+# Every ysl2 file that needs to be "compiled" separately, needs to generate a "marker" file
+# The marker serves as the make target.
+# If the marker file is older than its corresponding ysl2 file, or not exsiting, the ysl2 file will be "compiled"
+# Naming:
+# For a ysl2 file called "gen_example_stuff.ysl2", a marker file called "gen_example_stuff.marker" is expected.
+YML2_MARKERS= \
+	$(MARKER_DIR)/gen_java_Engine.marker \
+	$(MARKER_DIR)/gen_java_Message.marker \
+	$(MARKER_DIR)/gen_cpp_Engine.marker \
+	$(MARKER_DIR)/gen_cpp_Message.marker \
+	$(MARKER_DIR)/gen_throw_pEp_exception.marker
+
+# All code genration will be done upon change of these files
+YML2_INCLUDES= \
+	textutils.ysl2 \
+    types_c.ysl2 \
+    types_java.ysl2
+
+
+.PHONY: all codegen gen-status-codes create-dirs remove-dirs clean
+
+all: codegen
+
+# ------------- YML2 CodeGen --------------
+codegen: create-dirs gen-status-codes $(YML2_MARKERS)
+
+$(YML2_MARKERS): $(MARKER_DIR)/%.marker : %.ysl2 pEp.yml2 $(YML2_INCLUDES)
+	$(YML2_PROC) -y $< pEp.yml2
+
+gen-status-codes: status_list.yml2 passphrase_status_list.yml2
+
+status_list.yml2: pEp.yml2
+	bash ../../utils/extract_pEp_status_codes_from_engine.sh "$(PEP_HEADER)" $@
+
+passphrase_status_list.yml2: status_list.yml2
+	grep passphrase $< > $@
+
+# ------------- Housekeeping ---------------
+create-dirs:
+	mkdir -p $(MARKER_DIR)
+
+#rm -rf is too dangerous for vars
+remove-dirs:
+	rm -rf ../../build/marker
+
+clean: remove-dirs
+	rm -f status_list.yml2
+	rm -f passphrase_status_list.yml2
+
diff --git a/src/gen_cpp_Engine.ysl2 b/src/codegen/gen_cpp_Engine.ysl2
similarity index 95%
rename from src/gen_cpp_Engine.ysl2
rename to src/codegen/gen_cpp_Engine.ysl2
index 466e0db..50a4d0f 100644
--- a/src/gen_cpp_Engine.ysl2
+++ b/src/codegen/gen_cpp_Engine.ysl2
@@ -5,9 +5,12 @@ tstylesheet {
     include ./types_c.ysl2
     include ./types_java.ysl2
 
-    template "/namespace[@name='pEp']" apply "interface", 0;
+    template "/namespace[@name='pEp']" {
+        apply "interface", 0;
+        document("../../build/marker/gen_cpp_Engine.marker", "text") > ""
+    }
 
-    template "interface" document("foundation_pEp_jniadapter_{@name}.cc", "text")
+    template "interface" document("../cxx/foundation_pEp_jniadapter_{@name}.cc", "text")
         ||
         #include <cassert>
         #include <pEp/blacklist.h>
@@ -310,14 +313,7 @@ tstylesheet {
     }
 
     function "mangle" {
-        const "convert", "count(parm/stringlist|parm/string|parm/identity|parm/identitylist) > 0";
-
-        choose {
-            when "$convert"
-                > «concat('Java_foundation_pEp_jniadapter_', ../@name, '__1', str:replace(@name, '_', '_1'))»
-            otherwise
-                > «concat('Java_foundation_pEp_jniadapter_', ../@name, '_', str:replace(@name, '_', '_1'))»
-        }
+        > «concat('Java_foundation_pEp_jniadapter_', ../@name, '__1', str:replace(@name, '_', '_1'))»
     }
 
     template "parm", mode=sig {
diff --git a/src/gen_cpp_Message.ysl2 b/src/codegen/gen_cpp_Message.ysl2
similarity index 96%
rename from src/gen_cpp_Message.ysl2
rename to src/codegen/gen_cpp_Message.ysl2
index a5f4496..10672ef 100644
--- a/src/gen_cpp_Message.ysl2
+++ b/src/codegen/gen_cpp_Message.ysl2
@@ -5,12 +5,15 @@ tstylesheet {
     include ./textutils.ysl2
     include ./types_c.ysl2
 
-    template "/namespace[@name='pEp']" apply "struct", 0;
+    template "/namespace[@name='pEp']" {
+        apply "struct", 0;
+        document("../../build/marker/gen_cpp_Message.marker", "text") > ""
+    }
 
     template "struct" {
         const "jname" call "CamelCase" with "text", "@name";
 
-        document("foundation_pEp_jniadapter_{$jname}.cc", "text") {
+        document("../cxx/foundation_pEp_jniadapter_{$jname}.cc", "text") {
             ||
             #include <cassert>
             #include <pEp/mime.h>
diff --git a/src/gen_java_Engine.ysl2 b/src/codegen/gen_java_Engine.ysl2
similarity index 71%
rename from src/gen_java_Engine.ysl2
rename to src/codegen/gen_java_Engine.ysl2
index b3b07c3..10efac1 100644
--- a/src/gen_java_Engine.ysl2
+++ b/src/codegen/gen_java_Engine.ysl2
@@ -4,24 +4,41 @@ tstylesheet {
     include ./textutils.ysl2
     include ./types_java.ysl2
 
-    template "/namespace[@name='pEp']" apply "interface", 0;
+    template "/namespace[@name='pEp']" {
+        apply "interface", 0;
+        document("../../build/marker/gen_java_Engine.marker", "text") > ""
+    }
 
     template "interface" {
         const "cname" call "toJava" with "type", "@name";
-        document("foundation/pEp/jniadapter/{$cname}.java", "text")
+        document("../java/foundation/pEp/jniadapter/{$cname}.java", "text")
             ||
             package foundation.pEp.jniadapter;
 
+            import foundation.pEp.jniadapter.interfaces.*;
+            import foundation.pEp.jniadapter.exceptions.*;
             import java.util.ArrayList;
             import java.util.Vector;
 
-            final public class «$cname» extends AbstractEngine {
+            final public class «$cname» extends AbstractEngine implements EngineInterface {
                 public «$cname»() throws pEpException { }
-
-                `` apply "method", mode=plain
+                `` apply "method"
                 `` apply "basic"
             }
 
+            ||
+        document("../java/foundation/pEp/jniadapter/interfaces/{$cname}Interface.java", "text")
+            ||
+            package foundation.pEp.jniadapter.interfaces;
+
+            import foundation.pEp.jniadapter.*;
+            import java.util.ArrayList;
+            import java.util.Vector;
+
+            public interface «$cname»Interface extends AbstractEngineInterface {
+                `` apply "method", mode=java_interface
+                `` apply "basic", mode=java_interface
+            }
             ||
     }
 
@@ -29,48 +46,47 @@ tstylesheet {
         const "itype" call "toIntermediate" with "type", "@type";
         const "jtype" call "toJava" with "type", "@type";
 
-        choose {
-            when "name(parm/*[1])='bytearray|identitylist'"
-            ||
-            public native «$itype» «@name»(`apply "parm/*", mode=basic_iparm`);
-
-            ||
-            otherwise {
-            ||
-            private native «$itype» _«@name»(`apply "parm/*", mode=basic_iparm`);
+        ||
 
-            public «$jtype» «@name»(`apply "parm/*", mode=basic_parm`) {
+        // CodeGen "basic"
+        public «$jtype» «@name»(`apply "parm/*", mode=basic_parm`) {
+        ||
+        apply "parm/*", mode=basic_parm_set;
+        choose {
+            when "@type = 'void'"
+                |> _«@name»(`apply "parm/*", mode=basic_parm_name`);
+            when "@type = 'identity'"
+                |> return new Identity(_«@name»(`apply "parm/*", mode=basic_parm_name`));
+            when "@type = 'bool'"
+                |> return new Boolean(_«@name»(`apply "parm/*", mode=basic_parm_name`));
+            when "@type = 'identitylist'" {
             ||
-            apply "parm/*", mode=basic_parm_set;
-            choose {
-                when "@type = 'void'"
-                    |> _«@name»(`apply "parm/*", mode=basic_parm_name`);
-                when "@type = 'identity'"
-                    |> return new Identity(_«@name»(`apply "parm/*", mode=basic_parm_name`));
-                when "@type = 'bool'"
-                    |> return new Boolean(_«@name»(`apply "parm/*", mode=basic_parm_name`));
-                when "@type = 'identitylist'" {
-                ||
-                    Vector<_Identity> glist = _«@name»(`apply "parm/*", mode=basic_parm_name`);
-                    Vector<Identity> ret = new Vector<Identity>();
-                    if(glist != null) {
-                        for (_Identity i : glist) {
-                            ret.add(new Identity(i));
-                        }
+                Vector<_Identity> glist = _«@name»(`apply "parm/*", mode=basic_parm_name`);
+                Vector<Identity> ret = new Vector<Identity>();
+                if(glist != null) {
+                    for (_Identity i : glist) {
+                        ret.add(new Identity(i));
                     }
-                    return ret;
-                ||
-                } otherwise
-                    |> return AbstractEngine.toUTF16(_«@name»(`apply "parm/*", mode=basic_parm_name`));
-            }
-            ||
-            }
-
+                }
+                return ret;
             ||
-            }
+            } otherwise
+                |> return Utils.toUTF16(_«@name»(`apply "parm/*", mode=basic_parm_name`));
+        }
+        ||
         }
+
+        private native «$itype» _«@name»(`apply "parm/*", mode=basic_iparm`);
+        ||
     }
-    
+
+    template "basic" mode=java_interface {
+        const "jtype" call "toJava" with "type", "@type";
+        ||
+        public «$jtype» «@name»(`apply "parm/*", mode=basic_parm`);
+        ||
+    }
+
     template "*", mode=basic_parm_name choose {
         when "position() mod 2" {
             if "position() = 1 and name(.)='int'"
@@ -125,7 +141,7 @@ tstylesheet {
 
         if "not(position() mod 2)" choose {
             when "$ptype = 'string'"
-            | «$pitype» _«$pname» = AbstractEngine.toUTF8(«$pname»);
+            | «$pitype» _«$pname» = Utils.toUTF8(«$pname»);
             when "$ptype = 'bool'"
             | «$pitype» _«$pname» = «$pname».booleanValue();
             when "$ptype = 'bytearray'"
@@ -161,59 +177,47 @@ tstylesheet {
         }
     }
 
-    template "method", mode=plain {
-        const "convert", "count(parm/stringlist|parm/stringpairlist|parm/string|parm/identity|parm/identitylist) > 0";
+    template "method" {
         const "singlereturn", "count(parm/creates|parm/returns|parm/inout[../int]) = 1";
         const "multireturn", "count(parm/creates|parm/returns|parm/inout[../int]) > 1";
 
+        ||
+
+        //CodeGen "method"
+        ||
+
         if "$multireturn" {
-            if "$convert"
             ||
+            //CodeGen "mutlireturn" - class for return type
             private class _«@name»_Return {
             `` apply "parm[creates|returns|inout[../int]]", 1, mode=intermediate with "public", 1;
             }
 
             ||
-
-            ||
-            public class «@name»_Return {
-            `` apply "parm[creates|returns|inout[../int]]", 1, mode=java with "public", 1;
-            }
-
-            ||
         }
 
-        if "$convert"
         ||
-        private native `call "returnInter"` _«@name»(
-        `` apply "parm[in|inout]", 2, mode=intermediate
-            ) throws pEpException;
-
-        ||
-
-        ||
-        public `if "not($convert)" > native ``call "returnJava"` «@name»(
+        public `call "returnJava"` «@name»(
         `` apply "parm[in|inout]", 2, mode=java
-            ) throws pEpException`if "not($convert)" > ;`
+        ) throws pEpException
+        {
         ||
 
-        if "$convert" {
-            | {
-            apply "parm", mode=convertIn;
-
-            if "$singlereturn" choose {
-
-                // TODO factorize type conversion with multireturn and gen_java_message.java
+        apply "parm", mode=convertIn;
 
+        if "$singlereturn" {
+            choose {
                 when "count(parm[returns][stringlist|string|sstring]) > 0"
-                    |> return AbstractEngine.toUTF16(_«@name»(`apply "parm[in]", mode=call;`));
+                    |> return Utils.toUTF16(_«@name»(`apply "parm[in]", mode=call;`));
+
                 when "count(parm[returns]/stringpairlist) > 0"
                     ||
                         ArrayList<Pair<byte[], byte[]>> glist = _«@name»(`apply "parm[in]", mode=call;`);
                         if(glist != null){
                             ArrayList<Pair<String, String>> list = new ArrayList<Pair<String, String>>();
-                            for (Pair<byte[],byte[]> i : glist)
-                                list.add(new Pair<String, String>(AbstractEngine.toUTF16(i.first), AbstractEngine.toUTF16(i.second)));
+                            for (Pair<byte[],byte[]> i : glist) {
+                                list.add(new Pair<String, String>(Utils.toUTF16(i.first), Utils.toUTF16(i.second)));
+                            }
                             return list;
                         }
                         return null;
@@ -221,40 +225,53 @@ tstylesheet {
 
                 when "count(parm[returns]/identity) > 0"
                     |> return new Identity(_«@name»(`apply "parm[in]", mode=call;`));
+
                 when "count(parm[returns]/identitylist) > 0"
                     ||
                         Vector<_Identity> glist = _«@name»(`apply "parm[in]", mode=call;`);
                         if(glist != null){
                             Vector<Identity> list = new Vector<Identity>();
-                            for (_Identity i : glist)
+                            for (_Identity i : glist) {
                                 list.add(new Identity(i));
+                            }
                             return list;
                         }
                         return null;
                     ||
+
                 otherwise
                     |> return _«@name»(`apply "parm[in]", mode=call;`);
             }
+        }
 
-            if "$multireturn"
+        if "$multireturn" {
             ||
                 _«@name»_Return _result = _«@name»(`apply "parm[in|inout]", mode=call;`);
                 «@name»_Return result = new «@name»_Return();
                 `` apply "parm[creates|returns|inout[../int]]", mode=convertOut;
                 return result;
             ||
+        }
 
-            if "not($singlereturn) and not($multireturn)"
+        if "not($singlereturn) and not($multireturn)" {
             ||
                 _«@name»(`apply "parm[in]", mode=call;`);
-                return;
-            ||
-                
-            ||
-            }
             ||
         }
         ||
+        }
+
+        private native `call "returnInter"` _«@name»(
+        `` apply "parm[in|inout]", 2, mode=intermediate
+        ) throws pEpException;
+        ||
+    }
+
+    template "method", mode=java_interface {
+        ||
+        public `call "returnJava"` «@name»(
+        `` apply "parm[in|inout]", 2, mode=java
+        );
 
         ||
     }
@@ -302,7 +319,7 @@ tstylesheet {
 
         if "$dir = 'in' or $dir = 'inout'" choose {
             when "$type = 'string' or $type = 'stringlist'"
-                | ¡$type _«$name» = AbstractEngine.toUTF8(«$name»);
+                | ¡$type _«$name» = Utils.toUTF8(«$name»);
             when "$type = 'identity'"
                 ||
                 _Identity _«$name» = null; 
@@ -313,8 +330,9 @@ tstylesheet {
             when "$type = 'identitylist'"
                 ||
                 Vector<_Identity> _«$name» = new Vector<_Identity>();
-                for (Identity i : «$name»)
+                for (Identity i : «$name») {
                     _«$name».add(new _Identity(i));
+                }
                 ||
         }
     }
@@ -326,7 +344,7 @@ tstylesheet {
 
         if "$dir != 'in'" choose {
             when "$type = 'string' or $type = 'stringlist'"
-                | result.«$name» = AbstractEngine.toUTF16(_result.«$name»);
+                | result.«$name» = Utils.toUTF16(_result.«$name»);
             when "$type = 'identity'"
                 | result.«$name» = Identity(«$name»);
             otherwise
diff --git a/src/codegen/gen_java_Message.ysl2 b/src/codegen/gen_java_Message.ysl2
new file mode 100644
index 0000000..7007f6f
--- /dev/null
+++ b/src/codegen/gen_java_Message.ysl2
@@ -0,0 +1,327 @@
+include yslt.yml2
+
+tstylesheet {
+    include ./textutils.ysl2
+    include ./types_java.ysl2
+
+    template "/namespace[@name='pEp']" {
+        apply "struct|enum|exception", 0;
+        document "../java/foundation/pEp/jniadapter/exceptions/pEpException.java", "text" {
+            ||
+            package foundation.pEp.jniadapter.exceptions;
+
+            public class pEpException extends RuntimeException {
+              public pEpException(String message) {
+                super(message);
+              }
+            }
+            ||
+        }
+        document("../../build/marker/gen_java_Message.marker", "text") > ""
+    }
+
+    template "struct" {
+        const "cname" call "toJava" with "type", "@name";
+        document("../java/foundation/pEp/jniadapter/{$cname}.java", "text")
+            ||
+            package foundation.pEp.jniadapter;
+
+            import foundation.pEp.jniadapter.interfaces.*;
+            import foundation.pEp.jniadapter.exceptions.*;
+            import java.util.ArrayList;
+            import java.util.Vector;
+            import java.util.Date;
+            import java.util.HashMap;
+            import java.io.Serializable;
+
+            public class «$cname» implements MessageInterface, AutoCloseable, Serializable {
+                private static final long serialVersionUID = 2119420428331150924L;
+                private long handle;
+
+                native long init();
+                native void release(long handle);
+
+                public «$cname»() {
+                    handle = init();
+                }
+
+                private native long _«$cname»(
+                        byte[] mime_text
+                    ) throws pEpException;
+                
+                public «$cname»(String mime_text) {
+                    byte[] _mime_text = Utils.toUTF8(mime_text);
+                    handle = _«$cname»(_mime_text);
+                }
+
+                private native byte[] _encodeMIME() throws pEpException;
+
+                public String encodeMIME() {
+                    return Utils.toUTF16(_encodeMIME());
+                }
+
+                private «$cname»(long h) {
+                    handle = h;
+                }
+
+                public final void close() {
+                    release(handle);
+                }
+
+                final protected long getHandle() {
+                    return handle;
+                }
+
+                `` apply "enum", mode=inner
+                `` apply "*[name(.)!='enum']", mode=entry
+            }
+            ||
+        document("../java/foundation/pEp/jniadapter/interfaces/{$cname}Interface.java", "text")
+            ||
+            package foundation.pEp.jniadapter.interfaces;
+
+            import foundation.pEp.jniadapter.*;
+            import foundation.pEp.jniadapter.Message.*;
+            import java.util.Date;
+            import java.util.Vector;
+            import java.util.ArrayList;
+
+            public interface «$cname»Interface {
+                public String encodeMIME();
+
+                `` apply "*[name(.)!='enum']", mode=interface
+            }
+            ||
+    }
+
+    template "enum" {
+        const "jname" call "toJava" with "type", "@name";
+        document("../java/foundation/pEp/jniadapter/{$jname}.java", "text")
+            ||
+            // CodeGen template enum
+            package foundation.pEp.jniadapter;
+
+            import java.util.HashMap;
+
+            `` apply ".", 0, mode=inner
+            ||
+
+    }
+
+    template "enum", mode=inner {
+        const "jname" call "CamelCase" with "text", "@name";
+        ||
+        // CodeGen template enum, mode=inner
+        public enum «$jname» {
+            `` apply "*", mode=value
+            ;
+
+            public final int value;
+
+            private static HashMap<Integer, «$jname»> intMap;
+
+            private «$jname»(int value) {
+                this.value = value;
+            }
+
+            public static «$jname» getByInt(int value){
+                if (intMap == null) {
+                    intMap = new HashMap<Integer, «$jname»>();
+                    for («$jname» s : «$jname».values()) {
+                        intMap.put(s.value, s);
+                    }
+                }
+                if (intMap.containsKey(value)) {
+                    return intMap.get(value);
+                }
+                return null;
+            }
+        }
+
+        ||
+    }
+
+    function "exception" {
+        param "name";
+
+        document "../java/foundation/pEp/jniadapter/exceptions/{$name}.java", "text" {
+            | package foundation.pEp.jniadapter.exceptions;
+            |
+            | public class «$name» extends pEpException {
+            |   public «$name»(String message) {
+            |     super(message);
+            |   }
+            | }
+        }
+    }
+
+    template "exception" for "*[text()!=0]" call "exception"
+        with "name" call "CamelCase" with "text", "name(.)";
+
+
+    template "*", mode=entry {
+        const "ctype", "name(.)";
+        const "type" call "toJava" with "type", "name(.)";
+        const "itype" call "toIntermediate" with "type", "name(.)";
+        const "name" call "toJava" with "type", "name(*[position()=1])";
+
+        ||
+        // CodeGen template * mode=entry
+        ||
+        choose {
+            when "$ctype = 'identity'" {
+                ||
+                // Property type: Identity. [java: «$type», intermediate: «$itype», ctype: «$ctype»]
+                public «$type» get«$name»() {
+                    «$itype» res = _get«$name»();
+                    if (res != null) {
+                        return new «$type»(_get«$name»());
+                    } else {
+                        return null;
+                    }
+                }
+                private native «$itype» _get«$name»();
+
+                public void set«$name»(«$type» value) {
+                    if (value != null) {
+                        _set«$name»(new «$itype»(value));
+                    } else {
+                        _set«$name»(null);
+                    }
+                }
+                private native void _set«$name»(«$itype» value);
+
+
+                ||
+            }
+
+            when "$ctype = 'identitylist' or $ctype = 'bloblist' or $ctype = 'stringlist' or $ctype = 'stringpairlist'" {
+                const "ename", "substring-after(substring($type,1,string-length($type)-1), '<')";
+                const "iename" choose {
+                    when "$ctype = 'stringlist'" > byte[]
+                    when "$ctype = 'stringpairlist'" > Pair<byte[],byte[]>
+                    otherwise > _«$ename»
+                }
+                const "convget" choose {
+                    when "$ctype = 'stringlist'" > Utils.toUTF16(i)
+                    when "$ctype = 'stringpairlist'" > new Pair<String, String>(Utils.toUTF16(i.first), Utils.toUTF16(i.second))
+                    otherwise > new «$ename»(i)
+                }
+                const "convset" choose {
+                    when "$ctype = 'stringlist'" > Utils.toUTF8(i)
+                    when "$ctype = 'stringpairlist'" > new Pair<byte[],byte[]>(Utils.toUTF8(i.first), Utils.toUTF8(i.second))
+                    otherwise > new _«$ename»(i)
+                }
+                ||
+                // Property type: list type. [java: «$type», intermediate: «$itype», ctype: «$ctype»]
+                public «$type» get«$name»() {
+                    «$itype» glist = _get«$name»();
+                    if (glist != null) {
+                        «$type» list = new «$type»();
+                        for («$iename» i : glist) {
+                            list.add(«$convget»);
+                        }
+                        return list;
+                    }
+                    return null;
+                }
+                private native «$itype» _get«$name»();
+
+                public void set«$name»(«$type» value) {
+                    if (value != null) {
+                        «$itype» list = new «$itype»();
+                        for («$ename» i : value) {
+                            list.add(«$convset»);
+                        }
+                        _set«$name»(list);
+                    } else {
+                        _set«$name»(null);
+                    }
+                }
+                private native void _set«$name»(«$itype» value);
+
+
+                ||
+            }
+            
+            when "$itype != $type" {
+                ||
+                // Property type: differs from intermediate. [java: «$type», intermediate: «$itype», ctype: «$ctype»]
+                public «$type» get«$name»() {
+                    «$itype» res = _get«$name»();
+                    if (res != null) {
+                        return Utils.toUTF16(res);
+                    } else {
+                        return null;
+                    }
+                }
+                private native «$itype» _get«$name»();
+
+                public void set«$name»(«$type» value) {
+                    if (value != null) {
+                        _set«$name»(Utils.toUTF8(value));
+                    } else {
+                        _set«$name»(new byte[0]);
+                    }
+                }
+                private native void _set«$name»(«$itype» value);
+
+
+                ||
+            }
+
+            when "../enum[@name=$ctype]" {
+                ||
+                // Property type: enum type. [java: «$type», intermediate: «$itype», ctype: «$ctype»]
+                public «$type» get«$name»() {
+                    return «$type».getByInt(_get«$name»());
+                }
+                private native int _get«$name»();
+                public void set«$name»(«$type» value) {
+                    if(value != null)
+                        _set«$name»(value.value);
+                    else
+                        _set«$name»(0);
+                }
+                private native void _set«$name»(int value);
+
+                ||
+            }
+
+            otherwise {
+                ||
+                // Property type: no intermediate type [java: «$type», intermediate: «$itype», ctype: «$ctype»]
+                public «$type» get«$name»() {
+                    return get«$name»();
+                }
+                private native «$type» _get«$name»();
+
+                public void set«$name»(«$type» value) {
+                    _set«$name»(value);
+                }
+                private native void _set«$name»(«$type» value);
+
+
+                ||
+            }
+        }
+    }
+
+    template "*", mode=interface {
+        const "type" call "toJava" with "type", "name(.)";
+        const "name" call "toJava" with "type", "name(*[position()=1])";
+
+        ||
+        public «$type» get«$name»();
+
+        public void set«$name»(«$type» value);
+
+        ||
+    }
+
+    template "*", mode=value {
+        const "name" call "toJava" with "type", "name(.)";
+        | «$name» («.»)`if "position()!=last()" > , `
+    }
+}
+
diff --git a/src/codegen/gen_throw_pEp_exception.ysl2 b/src/codegen/gen_throw_pEp_exception.ysl2
new file mode 100644
index 0000000..42d99ec
--- /dev/null
+++ b/src/codegen/gen_throw_pEp_exception.ysl2
@@ -0,0 +1,65 @@
+include yslt.yml2
+
+tstylesheet {
+    include ./textutils.ysl2
+
+    template "/" {
+        apply "namespace", 0;
+        document "../cxx/throw_pEp_exception.hh", "text"
+            ||
+            #pragma once
+
+            #include <jni.h>
+
+            namespace pEp {
+                namespace JNIAdapter {
+                    jint throw_pEp_Exception(JNIEnv *env, PEP_STATUS status);
+                };
+            };
+
+            ||
+        document("../../build/marker/gen_throw_pEp_exception.marker", "text") > ""
+    }
+
+    template "namespace"
+        document("../cxx/throw_pEp_exception.cc", "text")
+            ||
+            #include <assert.h>
+            #include <pEp/pEpEngine.h>
+            #include "throw_pEp_exception.hh"
+
+            namespace pEp {
+                namespace JNIAdapter {
+                    jint throw_pEp_Exception(JNIEnv *env, PEP_STATUS status)
+                    {
+                        jclass ex;
+                        const char *ex_name;
+
+                        switch (status) {
+                            `` apply "exception/*[text()!=0]", 4, mode=case
+                            default:
+                                assert(0);
+                                ex_name = "Exception";
+                        }
+
+                        ex = env->FindClass(ex_name);
+                        assert(ex);
+
+                        if (ex == NULL) {
+                            ex = env->FindClass("java/lang/NoClassDefFoundError");
+                            assert(ex);
+                        }
+
+                        return env->ThrowNew(ex, ex_name);
+                    }
+                };
+            };
+            ||
+
+    template "*", mode=case {
+        | case `call "UCASE" with "text", "name(.)"`:
+        |     ex_name = "foundation/pEp/jniadapter/exceptions/`call "CamelCase" with "text", "name(.)"`";
+        |     break;
+    }
+}
+
diff --git a/src/pEp.yml2 b/src/codegen/pEp.yml2
similarity index 100%
rename from src/pEp.yml2
rename to src/codegen/pEp.yml2
diff --git a/src/textutils.ysl2 b/src/codegen/textutils.ysl2
similarity index 100%
rename from src/textutils.ysl2
rename to src/codegen/textutils.ysl2
diff --git a/src/types_c.ysl2 b/src/codegen/types_c.ysl2
similarity index 100%
rename from src/types_c.ysl2
rename to src/codegen/types_c.ysl2
diff --git a/src/types_java.ysl2 b/src/codegen/types_java.ysl2
similarity index 100%
rename from src/types_java.ysl2
rename to src/codegen/types_java.ysl2
diff --git a/src/basic_api.cc b/src/cxx/basic_api.cc
similarity index 100%
rename from src/basic_api.cc
rename to src/cxx/basic_api.cc
diff --git a/src/foundation_pEp_jniadapter_AbstractEngine.cc b/src/cxx/foundation_pEp_jniadapter_AbstractEngine.cc
similarity index 98%
rename from src/foundation_pEp_jniadapter_AbstractEngine.cc
rename to src/cxx/foundation_pEp_jniadapter_AbstractEngine.cc
index 624b233..bdbf80e 100644
--- a/src/foundation_pEp_jniadapter_AbstractEngine.cc
+++ b/src/cxx/foundation_pEp_jniadapter_AbstractEngine.cc
@@ -264,7 +264,7 @@ JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_release(
     Adapter::session(pEp::Adapter::release);
 }
 
-JNIEXPORT jstring JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_getVersion(
+JNIEXPORT jstring JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1getVersion(
         JNIEnv *env,
         jobject obj
     )
@@ -280,7 +280,7 @@ JNIEXPORT jstring JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_getVersi
     return env->NewStringUTF(::get_engine_version());
 }
 
-JNIEXPORT jstring JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_getProtocolVersion(
+JNIEXPORT jstring JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1getProtocolVersion(
         JNIEnv *env,
         jobject obj
     )
@@ -331,7 +331,7 @@ static void *keyserver_thread_routine(void *arg)
     return (void *) status;
 }
 
-JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_startKeyserverLookup(
+JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1startKeyserverLookup(
         JNIEnv *env,
         jobject obj
     )
@@ -375,7 +375,7 @@ JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_startKeyser
     pthread_create(thread, nullptr, keyserver_thread_routine, (void *) queue);
 }
 
-JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_stopKeyserverLookup(
+JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1stopKeyserverLookup(
         JNIEnv *env,
         jobject obj
     )
@@ -419,7 +419,7 @@ JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_stopKeyserv
     free(thread);
 }
 
-JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_startSync(
+JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1startSync(
         JNIEnv *env,
         jobject obj
     )
@@ -441,7 +441,7 @@ JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_startSync(
     }
 }
 
-JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_stopSync(
+JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1stopSync(
         JNIEnv *env,
         jobject obj
     )
@@ -458,7 +458,7 @@ JNIEXPORT void JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_stopSync(
 //    Adapter::shutdown();
 }
 
-JNIEXPORT jboolean JNICALL Java_foundation_pEp_jniadapter_AbstractEngine_isSyncRunning(
+JNIEXPORT jboolean JNICALL Java_foundation_pEp_jniadapter_AbstractEngine__1isSyncRunning(
         JNIEnv *env,
         jobject obj
     )
diff --git a/src/foundation_pEp_jniadapter__Blob.cc b/src/cxx/foundation_pEp_jniadapter__Blob.cc
similarity index 100%
rename from src/foundation_pEp_jniadapter__Blob.cc
rename to src/cxx/foundation_pEp_jniadapter__Blob.cc
diff --git a/src/get_header.cc b/src/cxx/get_header.cc
similarity index 100%
rename from src/get_header.cc
rename to src/cxx/get_header.cc
diff --git a/src/identity_api.cc b/src/cxx/identity_api.cc
similarity index 100%
rename from src/identity_api.cc
rename to src/cxx/identity_api.cc
diff --git a/src/jniutils.cc b/src/cxx/jniutils.cc
similarity index 100%
rename from src/jniutils.cc
rename to src/cxx/jniutils.cc
diff --git a/src/jniutils.hh b/src/cxx/jniutils.hh
similarity index 100%
rename from src/jniutils.hh
rename to src/cxx/jniutils.hh
diff --git a/src/passphrase_callback.hh b/src/cxx/passphrase_callback.hh
similarity index 100%
rename from src/passphrase_callback.hh
rename to src/cxx/passphrase_callback.hh
diff --git a/src/passphrase_callback.hxx b/src/cxx/passphrase_callback.hxx
similarity index 100%
rename from src/passphrase_callback.hxx
rename to src/cxx/passphrase_callback.hxx
diff --git a/src/foundation/pEp/jniadapter/Engine.java.target b/src/foundation/pEp/jniadapter/Engine.java.target
deleted file mode 100644
index 7708586..0000000
--- a/src/foundation/pEp/jniadapter/Engine.java.target
+++ /dev/null
@@ -1,28 +0,0 @@
-package foundation.pEp.jniadapter;
-
-import java.util.ArrayList;
-import java.util.Vector;
-
-final public class Engine extends AbstractEngine {
-    public Engine() throws pEpException { }
-
-    public native Message encrypt_message(
-            Message src,
-            ArrayList<String> extra,
-            Message.EncFormat enc_format
-        ) throws pEpException;
-
-    public class DecryptResult {
-        public Message dst;
-        public Color color;
-    }
-
-    public native DecryptResult decrypt_message(
-            Message src,
-            ArrayList<String> keylist
-        ) throws pEpException;
-
-    public native Color outgoing_message_color(
-            Message msg
-        ) throws pEpException;
-}
diff --git a/src/foundation/pEp/jniadapter/Message.java.target b/src/foundation/pEp/jniadapter/Message.java.target
deleted file mode 100644
index 6cdc3e6..0000000
--- a/src/foundation/pEp/jniadapter/Message.java.target
+++ /dev/null
@@ -1,218 +0,0 @@
-package foundation.pEp.jniadapter;
-
-import java.util.ArrayList;
-import java.util.Vector;
-import java.util.Date;
-import java.util.HashMap;
-
-public class Message implements AutoCloseable {
-    private final long handle;
-
-    native long init();
-    native void release(long handle);
-
-    public Message() {
-        handle = init();
-    }
-
-    public final void close() {
-        release(handle);
-    }
-
-    public enum TextFormat {
-        Plain (0), 
-        Html (1), 
-        Other (255)
-        ;
-    
-        static class Management {
-            public static final HashMap<Integer, TextFormat> tag =
-                    new HashMap<Integer, TextFormat>();
-        }
-    
-        public final int value;
-    
-        TextFormat(int value) {
-            this.value = value;
-            fill(value);
-        }
-    
-        private void fill(int value) {
-            Management.tag.put(value, this);
-        }
-    }
-    
-    public enum Direction {
-        Incoming (0), 
-        Outgoing (1)
-        ;
-    
-        static class Management {
-            public static final HashMap<Integer, Direction> tag =
-                    new HashMap<Integer, Direction>();
-        }
-    
-        public final int value;
-    
-        Direction(int value) {
-            this.value = value;
-            fill(value);
-        }
-    
-        private void fill(int value) {
-            Management.tag.put(value, this);
-        }
-    }
-    
-    public enum EncFormat {
-        None (0), 
-        Pieces (1), 
-        SMIME (2), 
-        PGPMIME (3), 
-        PEP (4)
-        ;
-    
-        static class Management {
-            public static final HashMap<Integer, EncFormat> tag =
-                    new HashMap<Integer, EncFormat>();
-        }
-    
-        public final int value;
-    
-        EncFormat(int value) {
-            this.value = value;
-            fill(value);
-        }
-    
-        private void fill(int value) {
-            Management.tag.put(value, this);
-        }
-    }
-    
-    private native int _getDir();
-    private native void _setDir(int value);
-    public Direction getDir() {
-        return Direction.tag.get(_getDir());
-    }
-    public void setDir(Direction value) {
-        _setDir(value.value);
-    }
-    
-    private native byte[] _getId();
-    private native void _setId(byte[] value);
-    public String getId() {
-        return AbstractEngine.toUTF16(_getId());
-    }
-    public void setId(String value) {
-        _setId(AbstractEngine.toUTF8(value));
-    }
-    
-    private native byte[] _getShortmsg();
-    private native void _setShortmsg(byte[] value);
-    public String getShortmsg() {
-        return AbstractEngine.toUTF16(_getShortmsg());
-    }
-    public void setShortmsg(String value) {
-        _setShortmsg(AbstractEngine.toUTF8(value));
-    }
-    
-    private native byte[] _getLongmsg();
-    private native void _setLongmsg(byte[] value);
-    public String getLongmsg() {
-        return AbstractEngine.toUTF16(_getLongmsg());
-    }
-    public void setLongmsg(String value) {
-        _setLongmsg(AbstractEngine.toUTF8(value));
-    }
-    
-    private native byte[] _getLongmsgFormatted();
-    private native void _setLongmsgFormatted(byte[] value);
-    public String getLongmsgFormatted() {
-        return AbstractEngine.toUTF16(_getLongmsgFormatted());
-    }
-    public void setLongmsgFormatted(String value) {
-        _setLongmsgFormatted(AbstractEngine.toUTF8(value));
-    }
-    
-    public native ArrayList<Blob> getAttachments();
-    public native void setAttachments(ArrayList<Blob> value);
-    
-    public native Date getSent();
-    public native void setSent(Date value);
-    
-    public native Date getRecv();
-    public native void setRecv(Date value);
-    
-    private native AbstractEngine._Identity _getFrom();
-    private native void _setFrom(AbstractEngine._Identity value);
-    public Identity getFrom() {
-        return new _getFrom().getIdentity();
-    }
-    public void setFrom(Identity value) {
-        _setFrom(new AbstractEngine._Identity(value));
-    }
-    
-    public native ArrayList<Identity> getTo();
-    public native void setTo(ArrayList<Identity> value);
-    
-    public native Identity getRecvBy();
-    public native void setRecvBy(Identity value);
-    
-    public native ArrayList<Identity> getCc();
-    public native void setCc(ArrayList<Identity> value);
-    
-    public native ArrayList<Identity> getBcc();
-    public native void setBcc(ArrayList<Identity> value);
-    
-    public native ArrayList<Identity> getReplyTo();
-    public native void setReplyTo(ArrayList<Identity> value);
-    
-    private native ArrayList<byte[]> _getInReplyTo();
-    private native void _setInReplyTo(ArrayList<byte[]> value);
-    public ArrayList<String> getInReplyTo() {
-        return AbstractEngine.toUTF16(_getInReplyTo());
-    }
-    public void setInReplyTo(ArrayList<String> value) {
-        _setInReplyTo(AbstractEngine.toUTF8(value));
-    }
-    
-    private native ArrayList<byte[]> _getReferences();
-    private native void _setReferences(ArrayList<byte[]> value);
-    public ArrayList<String> getReferences() {
-        return AbstractEngine.toUTF16(_getReferences());
-    }
-    public void setReferences(ArrayList<String> value) {
-        _setReferences(AbstractEngine.toUTF8(value));
-    }
-    
-    private native ArrayList<byte[]> _getKeywords();
-    private native void _setKeywords(ArrayList<byte[]> value);
-    public ArrayList<String> getKeywords() {
-        return AbstractEngine.toUTF16(_getKeywords());
-    }
-    public void setKeywords(ArrayList<String> value) {
-        _setKeywords(AbstractEngine.toUTF8(value));
-    }
-    
-    private native byte[] _getComments();
-    private native void _setComments(byte[] value);
-    public String getComments() {
-        return AbstractEngine.toUTF16(_getComments());
-    }
-    public void setComments(String value) {
-        _setComments(AbstractEngine.toUTF8(value));
-    }
-    
-    private native Vector<Pair<byte[], byte[]>> _getOptFields();
-    private native void _setOptFields(Vector<Pair<byte[], byte[]>> value);
-    public Vector<Pair<String, String>> getOptFields() {
-        return AbstractEngine.toUTF16(_getOptFields());
-    }
-    public void setOptFields(Vector<Pair<String, String>> value) {
-        _setOptFields(AbstractEngine.toUTF8(value));
-    }
-    
-    public native Message.EncFormat getEncFormat();
-    public native void setEncFormat(Message.EncFormat value);
-    
-}
diff --git a/src/foundation/pEp/jniadapter/UniquelyIdentifiable.java b/src/foundation/pEp/jniadapter/UniquelyIdentifiable.java
deleted file mode 100644
index d599e9c..0000000
--- a/src/foundation/pEp/jniadapter/UniquelyIdentifiable.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package foundation.pEp.jniadapter;
-import java.util.concurrent.atomic.AtomicLong;
-
-abstract class UniquelyIdentifiable {
-    static final AtomicLong NEXT_ID = new AtomicLong(1);
-    final long id = NEXT_ID.getAndIncrement();
-
-    public long getId() {
-        return id;
-    }
-}
diff --git a/src/gen_java_Message.ysl2 b/src/gen_java_Message.ysl2
deleted file mode 100644
index a16658a..0000000
--- a/src/gen_java_Message.ysl2
+++ /dev/null
@@ -1,252 +0,0 @@
-include yslt.yml2
-
-tstylesheet {
-    include ./textutils.ysl2
-    include ./types_java.ysl2
-
-    template "/namespace[@name='pEp']" apply "struct|enum|exception", 0;
-
-    template "struct" {
-        const "cname" call "toJava" with "type", "@name";
-        document("foundation/pEp/jniadapter/{$cname}.java", "text")
-            ||
-            package foundation.pEp.jniadapter;
-
-            import java.util.ArrayList;
-            import java.util.Vector;
-            import java.util.Date;
-            import java.util.HashMap;
-            import java.io.Serializable;
-
-            public class «$cname» implements AutoCloseable, Serializable {
-                private static final long serialVersionUID = 2119420428331150924L;
-                private long handle;
-
-                native long init();
-                native void release(long handle);
-
-                public «$cname»() {
-                    handle = init();
-                }
-
-                private native long _«$cname»(
-                        byte[] mime_text
-                    ) throws pEpException;
-                
-                public «$cname»(String mime_text) {
-                    byte[] _mime_text = AbstractEngine.toUTF8(mime_text);
-                    handle = _«$cname»(_mime_text);
-                }
-
-                public native byte[] _encodeMIME() throws pEpException;
-
-                public String encodeMIME() {
-                    return AbstractEngine.toUTF16(_encodeMIME());
-                }
-
-                private «$cname»(long h) {
-                    handle = h;
-                }
-
-                public final void close() {
-                    release(handle);
-                }
-
-                final protected long getHandle() {
-                    return handle;
-                }
-
-                `` apply "enum", mode=inner
-                `` apply "*[name(.)!='enum']", mode=entry
-            }
-            ||
-    }
-
-    template "enum|exception" {
-        const "jname" call "toJava" with "type", "@name";
-        document("foundation/pEp/jniadapter/{$jname}.java", "text")
-            ||
-            package foundation.pEp.jniadapter;
-
-            import java.util.HashMap;
-            
-            `` apply ".", 0, mode=inner
-            ||
-    }
-
-    template "enum|exception", mode=inner {
-        const "jname" call "CamelCase" with "text", "@name";
-        ||
-        public enum «$jname» {
-            `` apply "*", mode=value
-            ;
-
-            public final int value;
-
-            private static HashMap<Integer, «$jname»> intMap;
-
-            private «$jname»(int value) {
-                this.value = value;
-            }
-
-            public static «$jname» getByInt(int value){
-                if (intMap == null) {
-                    intMap = new HashMap<Integer, «$jname»>();
-                    for («$jname» s : «$jname».values()) {
-                        intMap.put(s.value, s);
-                    }
-                }
-                if (intMap.containsKey(value)) {
-                    return intMap.get(value);
-                }
-                return null;
-            }
-        }
-        ||
-    }
-
-    template "*", mode=entry {
-        const "ctype", "name(.)";
-        const "type" call "toJava" with "type", "name(.)";
-        const "itype" call "toIntermediate" with "type", "name(.)";
-        const "name" call "toJava" with "type", "name(*[position()=1])";
-
-        choose {
-            when "$ctype = 'identity'"
-            ||
-            private native «$itype» _get«$name»();
-            private native void _set«$name»(«$itype» value);
-            public «$type» get«$name»() {
-                «$itype» res = _get«$name»();
-                if(res != null){
-                    return new «$type»(_get«$name»());
-                }else{
-                    return null;
-                }
-            }
-            public void set«$name»(«$type» value) {
-                if(value != null)
-                    _set«$name»(new «$itype»(value));
-                else
-                    _set«$name»(null);
-            }
-            
-            ||
-
-            when "$ctype = 'identitylist' or $ctype = 'bloblist' or $ctype = 'stringlist' or $ctype = 'stringpairlist'"
-            {
-
-                const "ename", "substring-after(substring($type,1,string-length($type)-1), '<')";
-                const "iename" choose {
-                    when "$ctype = 'stringlist'" > byte[]
-                    when "$ctype = 'stringpairlist'" > Pair<byte[],byte[]>
-                    otherwise > _«$ename»
-                }
-                const "convget" choose {
-                    when "$ctype = 'stringlist'" > AbstractEngine.toUTF16(i)
-                    when "$ctype = 'stringpairlist'" > new Pair<String, String>(AbstractEngine.toUTF16(i.first), AbstractEngine.toUTF16(i.second))
-                    otherwise > new «$ename»(i)
-                }
-                const "convset" choose {
-                    when "$ctype = 'stringlist'" > AbstractEngine.toUTF8(i)
-                    when "$ctype = 'stringpairlist'" > new Pair<byte[],byte[]>(AbstractEngine.toUTF8(i.first), AbstractEngine.toUTF8(i.second))
-                    otherwise > new _«$ename»(i)
-                }
-                ||
-                private native «$itype» _get«$name»();
-                private native void _set«$name»(«$itype» value);
-                public «$type» get«$name»() {
-                    «$itype» glist = _get«$name»();
-                    if(glist != null){
-                        «$type» list = new «$type»();
-                        for («$iename» i : glist)
-                            list.add(«$convget»);
-                        return list;
-                    }
-                    return null;
-                }
-                public void set«$name»(«$type» value) {
-                    if(value != null){
-                        «$itype» list = new «$itype»();
-                        for («$ename» i : value)
-                            list.add(«$convset»);
-                        _set«$name»(list);
-                    }else{
-                        _set«$name»(null);
-                    }
-                }
-                
-                ||
-            }
-            
-            when "$itype != $type"
-            ||
-            private native «$itype» _get«$name»();
-            private native void _set«$name»(«$itype» value);
-            public «$type» get«$name»() {
-                «$itype» res = _get«$name»();
-                if(res != null)
-                    return AbstractEngine.toUTF16(res);
-                else
-                    return null;
-            }
-            public void set«$name»(«$type» value) {
-                if(value != null)
-                    _set«$name»(AbstractEngine.toUTF8(value));
-                else
-                    _set«$name»(new byte[0]);
-            }
-
-            ||
-
-            when "$itype != $type"
-            ||
-            private native «$itype» _get«$name»();
-            private native void _set«$name»(«$itype» value);
-            public «$type» get«$name»() {
-                «$itype» res = _get«$name»();
-                if(res != null)
-                    return AbstractEngine.toUTF16(res);
-                else
-                    return null;
-            }
-            public void set«$name»(«$type» value) {
-                if(value != null)
-                    _set«$name»(AbstractEngine.toUTF8(value));
-                else
-                    _set«$name»(null);
-            }
-
-            ||
-
-            when "../enum[@name=$ctype]"
-            ||
-            private native int _get«$name»();
-            public «$itype» get«$name»() {
-                return «$itype».getByInt(_get«$name»());
-            }
-            private native void _set«$name»(int value);
-            public void set«$name»(«$itype» value) {
-                if(value != null)
-                    _set«$name»(value.value);
-                else
-                    _set«$name»(0);
-            }
-
-            ||
-
-            otherwise
-            ||
-            public native «$itype» get«$name»();
-            public native void set«$name»(«$itype» value);
-
-            ||
-        }
-    }
-
-    template "*", mode=value {
-        const "name" call "toJava" with "type", "name(.)";
-        | «$name» («.»)`if "position()!=last()" > , `
-    }
-}
-
diff --git a/src/gen_java_exceptions.ysl2 b/src/gen_java_exceptions.ysl2
deleted file mode 100644
index ecdca21..0000000
--- a/src/gen_java_exceptions.ysl2
+++ /dev/null
@@ -1,35 +0,0 @@
-include yslt.yml2
-
-tstylesheet {
-    include ./textutils.ysl2
-
-    template "/" {
-        | package foundation.pEp.jniadapter;
-        | 
-        | public class pEpException extends RuntimeException {
-        |   public pEpException(String message) {
-        |     super(message);
-        |   }
-        | }
-
-        apply "namespace/exception[@name='Status']", 0;
-    }
-
-    function "exception" {
-        param "name";
-
-        document "foundation/pEp/jniadapter/{$name}.java", "text" {
-            | package foundation.pEp.jniadapter;
-            |
-            | public class «$name» extends pEpException {
-            |   public «$name»(String message) {
-            |     super(message);
-            |   }
-            | }
-        }
-    }
-
-    template "exception" for "*[text()!=0]" call "exception"
-        with "name" call "CamelCase" with "text", "name(.)";
-}
-
diff --git a/src/gen_throw_pEp_exception.ysl2 b/src/gen_throw_pEp_exception.ysl2
deleted file mode 100644
index 3c9d3ad..0000000
--- a/src/gen_throw_pEp_exception.ysl2
+++ /dev/null
@@ -1,64 +0,0 @@
-include yslt.yml2
-
-tstylesheet {
-    include ./textutils.ysl2
-
-    template "/" {
-        apply "namespace", 0;
-        document "throw_pEp_exception.hh", "text"
-            ||
-            #pragma once
-
-            #include <jni.h>
-
-            namespace pEp {
-                namespace JNIAdapter {
-                    jint throw_pEp_Exception(JNIEnv *env, PEP_STATUS status);
-                };
-            };
-
-            ||
-
-    }
-
-    template "namespace"
-        ||
-        #include <assert.h>
-        #include <pEp/pEpEngine.h>
-        #include "throw_pEp_exception.hh"
-
-        namespace pEp {
-            namespace JNIAdapter {
-                jint throw_pEp_Exception(JNIEnv *env, PEP_STATUS status)
-                {
-                    jclass ex;
-                    const char *ex_name;
-        
-                    switch (status) {
-                        `` apply "exception/*[text()!=0]", 4, mode=case
-                        default:
-                            assert(0);
-                            ex_name = "Exception";
-                    }
-        
-                    ex = env->FindClass(ex_name);
-                    assert(ex);
-        
-                    if (ex == NULL) {
-                        ex = env->FindClass("java/lang/NoClassDefFoundError");
-                        assert(ex);
-                    }
-        
-                    return env->ThrowNew(ex, ex_name);
-                }
-            };
-        };
-        ||
-
-    template "*", mode=case {
-        | case `call "UCASE" with "text", "name(.)"`:
-        |     ex_name = "foundation/pEp/jniadapter/`call "CamelCase" with "text", "name(.)"`";
-        |     break;
-    }
-}
-
diff --git a/src/foundation/pEp/jniadapter/AbstractEngine.java b/src/java/foundation/pEp/jniadapter/AbstractEngine.java
similarity index 57%
rename from src/foundation/pEp/jniadapter/AbstractEngine.java
rename to src/java/foundation/pEp/jniadapter/AbstractEngine.java
index cb56de8..b7aba8b 100644
--- a/src/foundation/pEp/jniadapter/AbstractEngine.java
+++ b/src/java/foundation/pEp/jniadapter/AbstractEngine.java
@@ -4,11 +4,11 @@ import java.util.ArrayList;
 import java.util.Vector;
 
 import foundation.pEp.jniadapter.Sync.DefaultCallback;
+import foundation.pEp.jniadapter.interfaces.*;
+import foundation.pEp.jniadapter.exceptions.*;
 
-import java.io.UnsupportedEncodingException;
-import java.text.Normalizer;
 
-abstract class AbstractEngine extends UniquelyIdentifiable implements AutoCloseable {
+abstract class AbstractEngine extends UniquelyIdentifiable implements AbstractEngineInterface {
     static {
         System.loadLibrary("pEpJNI");
     }
@@ -23,6 +23,9 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
     private native void init();
     private native void release();
 
+    private long keyserverThread;
+    private long keyserverQueue;
+
     public AbstractEngine() throws pEpException {
         synchronized (AbstractEngine.class) {
             init();
@@ -35,124 +38,52 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
         }
     }
 
-    public native String getVersion();
-    public native String getProtocolVersion();
-
-    private long keyserverThread;
-    private long keyserverQueue;
-
-    public native void startKeyserverLookup();
-    public native void stopKeyserverLookup();
-
-    public native void startSync();
-    public native void stopSync();
-    public native boolean isSyncRunning();
-
-    public static byte[] toUTF8(String str) {
-        if (str == null)
-            return null;
-
-        try {
-            String _str = Normalizer.normalize(str, Normalizer.Form.NFC);
-            byte _buf[] = _str.getBytes("UTF-8");
-            byte _cpy[] = new byte[_buf.length];
-            System.arraycopy(_buf,0,_cpy,0,_buf.length);
-            return _cpy;
-        }
-        catch (UnsupportedEncodingException e) {
-            assert false;
-            return new byte[0];
-        }
+    public String getVersion() {
+        return _getVersion();
     }
 
-    public static Vector<byte[]> toUTF8(Vector<String> list) {
-        if (list == null)
-            return null;
+    private native String _getVersion();
 
-        Vector<byte[]> result = new Vector<byte[]>(list.size());
 
-        for (int i=0; i<list.size(); i++)
-            result.add(toUTF8(list.get(i)));
-
-        return result;
+    public String getProtocolVersion() {
+        return _getProtocolVersion();
     }
 
-    public static Pair<byte[], byte[]> toUTF8(Pair<String, String> pair) {
-        if (pair == null)
-            return null;
-
-        Pair<byte[], byte[]> result = new Pair<byte[], byte[]>();
+    private native String _getProtocolVersion();
 
-        result.first = toUTF8(pair.first);
-        result.second = toUTF8(pair.second);
 
-        return result;
+    public void startKeyserverLookup() {
+        _startKeyserverLookup();
     }
 
-    public static ArrayList<Pair<byte[], byte[]>> toUTF8(ArrayList<Pair<String, String>> list) {
-        if (list == null)
-            return null;
-
-        ArrayList<Pair<byte[], byte[]>> result = new ArrayList<Pair<byte[], byte[]>>(list.size());
+    private native void _startKeyserverLookup();
 
-        for (int i=0; i<list.size(); i++)
-            result.set(i, toUTF8(list.get(i)));
-
-        return result;
+    public void stopKeyserverLookup() {
+        _startKeyserverLookup();
     }
 
-    public static String toUTF16(byte[] utf8) {
-        if (utf8 == null)
-            return null;
+    private native void _stopKeyserverLookup();
 
-        try {
-            byte newUtf8[] = new byte[utf8.length];
-            System.arraycopy(utf8,0,newUtf8,0,utf8.length);
 
-            return new String(newUtf8, "UTF-8");
-        }
-        catch (UnsupportedEncodingException e) {
-            assert false;
-            return new String();
-        }
+    public void startSync() {
+        _startSync();
     }
 
-    public static Vector<String> toUTF16(Vector<byte[]> list) {
-        if (list == null)
-            return null;
-
-        Vector<String> result = new Vector<String>(list.size());
+    private native void _startSync();
 
-        for (int i=0; i<list.size(); i++)
-            result.add(toUTF16(list.get(i)));
-
-        return result;
+    public void stopSync() {
+        _stopSync();
     }
 
-    public static Pair<String, String> toUTF16(Pair<byte[], byte[]> pair) {
-        if (pair == null)
-            return null;
-
-        Pair<String, String> result = new Pair<String,String>();
-
-        result.first = toUTF16(pair.first);
-        result.second = toUTF16(pair.second);
+    private native void _stopSync();
 
-        return result;
+    public boolean isSyncRunning() {
+        return _isSyncRunning();
     }
 
-    public static ArrayList<Pair<String, String>> toUTF16(ArrayList<Pair<byte[], byte[]>> list) {
-        if (list == null)
-            return null;
-
-        ArrayList<Pair<String, String>> result = new ArrayList<Pair<String, String>>(list.size());
-
-        for (int i=0; i<list.size(); i++)
-            result.set(i, toUTF16(list.get(i)));
-
-        return result;
-    }
+    private native boolean _isSyncRunning();
 
+    // Callbacks
     public void setMessageToSendCallback(Sync.MessageToSendCallback messageToSendCallback) {
         this.messageToSendCallback = messageToSendCallback;
     }
@@ -171,7 +102,7 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
         this.passphraseRequiredCallback = passphraseRequiredCallback;
     }
 
-    public int needsFastPollCallFromC(boolean fast_poll_needed) {
+    private int needsFastPollCallFromC(boolean fast_poll_needed) {
         if (needsFastPollCallback != null) {
             needsFastPollCallback.needsFastPollCallFromC(fast_poll_needed);
         } else {
@@ -180,7 +111,7 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
         return 0;
     }
 
-    public int notifyHandshakeCallFromC(_Identity _myself, _Identity _partner, SyncHandshakeSignal _signal) {
+    private int notifyHandshakeCallFromC(_Identity _myself, _Identity _partner, SyncHandshakeSignal _signal) {
         Identity myself = new Identity(_myself);
         Identity partner = (_partner != null) ? new Identity(_partner) : null;
 
@@ -193,7 +124,7 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
         return 0;
     }
 
-    public byte[] passphraseRequiredFromC(final PassphraseType passphraseType) {
+    private byte[] passphraseRequiredFromC(final PassphraseType passphraseType) {
         String ret = "";
         if (passphraseRequiredCallback != null) {
             System.out.println("calling passphraseRequiredCallback on engine ObjID:" + getId());
@@ -206,10 +137,10 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
             // this repeats MaxRetries times (currentluy hardcoded to 3)
             // Then the orig call will return with the PEP_STATUS (most likely PEP_PASSPHRASE_REQUIRED)
         }
-        return toUTF8(ret);
+        return Utils.toUTF8(ret);
     }
 
-    public int messageToSendCallFromC (Message message) {
+    private int messageToSendCallFromC (Message message) {
         System.out.println("pEpSync" + "messageToSendCallFromC: " + messageToSendCallback );
         if (messageToSendCallback != null) {
             messageToSendCallback.messageToSend(message);
@@ -228,11 +159,11 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
         ArrayList<Pair<String, String>> opts = new ArrayList<>();
         Pair<String, String> xpEp = new Pair<>();
         xpEp.first = "X-pEp-Version";
-        xpEp.second = this.getProtocolVersion();;
+        xpEp.second = this.getProtocolVersion();
         opts.add(xpEp);
         msg.setOptFields(opts);
 
-        if(encFormat == Message.EncFormat.PEP) {
+        if (encFormat == Message.EncFormat.PEP) {
             // For EncFormat.PEP
             // The pgpText goes into the attachment index 1
             msg.setShortmsg("p≡p");
@@ -253,14 +184,12 @@ abstract class AbstractEngine extends UniquelyIdentifiable implements AutoClosea
             attachments.add(att0);
             attachments.add(att1);
             msg.setAttachments(attachments);
-        }
-        else if (encFormat == Message.EncFormat.PEPEncInlineEA) {
+        } else if (encFormat == Message.EncFormat.PEPEncInlineEA) {
             // For EncFormat.PEPEncInlineEA
             // The pgpText goes into the longMessage
             msg.setShortmsg("");
             msg.setLongmsg(pgpText);
-        }
-        else {
+        } else {
             throw new pEpCannotEncode("Message.Encformat not supported: " + encFormat.toString());
         }
 
diff --git a/src/foundation/pEp/jniadapter/Blob.java b/src/java/foundation/pEp/jniadapter/Blob.java
similarity index 68%
rename from src/foundation/pEp/jniadapter/Blob.java
rename to src/java/foundation/pEp/jniadapter/Blob.java
index f246e0c..4fdffa4 100644
--- a/src/foundation/pEp/jniadapter/Blob.java
+++ b/src/java/foundation/pEp/jniadapter/Blob.java
@@ -1,8 +1,9 @@
 package foundation.pEp.jniadapter;
 
+import foundation.pEp.jniadapter.interfaces.*;
 import java.io.Serializable;
 
-public class Blob implements Serializable {
+public class Blob implements BlobInterface, Serializable {
     public byte[] data;
     public String mime_type;
     public String filename;
@@ -11,10 +12,18 @@ public class Blob implements Serializable {
         mime_type = "application/octet-stream";
     }
 
-    /** Human readable string representation of Blob.
+    Blob(_Blob b) {
+        data = b.data;
+        mime_type = Utils.toUTF16(b.mime_type);
+        filename = Utils.toUTF16(b.filename);
+    }
+
+    /**
+     * Human readable string representation of Blob.
      * The data field is ASN.1 XER decoded for mime_types:
      * "application/pEp.sync"
      * "application/pEp.keyreset"
+     *
      * @return String Blob as String
      */
     public String toString() {
@@ -22,15 +31,10 @@ public class Blob implements Serializable {
         String ret = "";
         ret += "mime_type: \"" + mime_type + "\"\n";
         ret += "filename: \"" + filename + "\"\n";
-        ret += "data plain: \"" + AbstractEngine.toUTF16(data) + "\"\n";
+        ret += "data plain: \"" + Utils.toUTF16(data) + "\"\n";
         ret += "data decoded: \"" + _b.dataToXER() + "\"\n";
         return ret;
     }
 
-    Blob(_Blob b) {
-        data = b.data;
-        mime_type = AbstractEngine.toUTF16(b.mime_type);
-        filename = AbstractEngine.toUTF16(b.filename);
-    }
 }
 
diff --git a/src/foundation/pEp/jniadapter/CommType.java b/src/java/foundation/pEp/jniadapter/CommType.java
similarity index 100%
rename from src/foundation/pEp/jniadapter/CommType.java
rename to src/java/foundation/pEp/jniadapter/CommType.java
diff --git a/src/foundation/pEp/jniadapter/Identity.java b/src/java/foundation/pEp/jniadapter/Identity.java
similarity index 74%
rename from src/foundation/pEp/jniadapter/Identity.java
rename to src/java/foundation/pEp/jniadapter/Identity.java
index 756102c..2b0cdde 100644
--- a/src/foundation/pEp/jniadapter/Identity.java
+++ b/src/java/foundation/pEp/jniadapter/Identity.java
@@ -1,8 +1,9 @@
 package foundation.pEp.jniadapter;
 
+import foundation.pEp.jniadapter.interfaces.*;
 import java.io.Serializable;
 
-public class Identity implements Serializable{
+public class Identity implements IdentityInterface, Serializable {
     public String address;
     public String fpr;
     public String user_id;
@@ -23,27 +24,26 @@ public class Identity implements Serializable{
     }
 
     public Identity(_Identity i) {
-        address = AbstractEngine.toUTF16(i.address);
-        fpr = AbstractEngine.toUTF16(i.fpr);
-        user_id = AbstractEngine.toUTF16(i.user_id);
-        username = AbstractEngine.toUTF16(i.username);
+        address = Utils.toUTF16(i.address);
+        fpr = Utils.toUTF16(i.fpr);
+        user_id = Utils.toUTF16(i.user_id);
+        username = Utils.toUTF16(i.username);
         comm_type = CommType.Management.tag.get(i.comm_type);
-        lang = AbstractEngine.toUTF16(i.lang);
+        lang = Utils.toUTF16(i.lang);
         me = i.me;
         flags = i.flags;
     }
 
-    @Override
-    public String toString() {
-        return address + "::" + username + "\n" +
-                user_id + "::" + fpr;
+    public Rating getRating() {
+        return Rating.getByInt(_getRating(comm_type.value));
     }
 
-    // Native
     private native int _getRating(int commType);
 
-    public Rating getRating() {
-        return Rating.getByInt(_getRating(comm_type.value));
+    @Override
+    public String toString() {
+        return address + "::" + username + "\n" +
+                user_id + "::" + fpr;
     }
 
 }
diff --git a/src/foundation/pEp/jniadapter/Pair.java b/src/java/foundation/pEp/jniadapter/Pair.java
similarity index 100%
rename from src/foundation/pEp/jniadapter/Pair.java
rename to src/java/foundation/pEp/jniadapter/Pair.java
diff --git a/src/foundation/pEp/jniadapter/Sync.java b/src/java/foundation/pEp/jniadapter/Sync.java
similarity index 77%
rename from src/foundation/pEp/jniadapter/Sync.java
rename to src/java/foundation/pEp/jniadapter/Sync.java
index 7593477..21f28e0 100644
--- a/src/foundation/pEp/jniadapter/Sync.java
+++ b/src/java/foundation/pEp/jniadapter/Sync.java
@@ -1,12 +1,8 @@
 package foundation.pEp.jniadapter;
 
-import foundation.pEp.jniadapter.Identity;
-import foundation.pEp.jniadapter.Message;
-import foundation.pEp.jniadapter.pEpException;
-
 public interface Sync {
 
-     
+
     interface NeedsFastPollCallback {
         void needsFastPollCallFromC(Boolean fast_poll_needed);
     }
@@ -23,8 +19,7 @@ public interface Sync {
         String passphraseRequired(final PassphraseType pEpStatus);
     }
 
-    public class DefaultCallback 
-            implements Sync.MessageToSendCallback, Sync.NotifyHandshakeCallback,  Sync.NeedsFastPollCallback {
+    public class DefaultCallback implements Sync.MessageToSendCallback, Sync.NotifyHandshakeCallback, Sync.NeedsFastPollCallback {
         @Override
         public void needsFastPollCallFromC(Boolean fast_poll_needed) {
             System.out.println("Need fast Poll");
@@ -34,7 +29,7 @@ public interface Sync {
         public void messageToSend(Message message) {
             System.out.println("messageToSend Defualt Callback");
         }
-        
+
         @Override
         public void notifyHandshake(Identity myself, Identity partner, SyncHandshakeSignal signal) {
             System.out.println("notifyHandshake Default Callback");
diff --git a/src/java/foundation/pEp/jniadapter/UniquelyIdentifiable.java b/src/java/foundation/pEp/jniadapter/UniquelyIdentifiable.java
new file mode 100644
index 0000000..39d8004
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/UniquelyIdentifiable.java
@@ -0,0 +1,12 @@
+package foundation.pEp.jniadapter;
+import java.util.concurrent.atomic.AtomicLong;
+
+// Abstract here so you can only inherit from, but not instantiate
+abstract public class UniquelyIdentifiable {
+    private static final AtomicLong NEXT_ID = new AtomicLong(1);
+    private final long id = NEXT_ID.getAndIncrement();
+
+    protected long getId() {
+        return id;
+    }
+}
diff --git a/src/java/foundation/pEp/jniadapter/Utils.java b/src/java/foundation/pEp/jniadapter/Utils.java
new file mode 100644
index 0000000..709998f
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/Utils.java
@@ -0,0 +1,115 @@
+package foundation.pEp.jniadapter;
+
+import java.io.UnsupportedEncodingException;
+import java.text.Normalizer;
+import java.util.ArrayList;
+import java.util.Vector;
+
+public class Utils {
+    private Utils() { }
+
+    public static byte[] toUTF8(String str) {
+        if (str == null)
+            return null;
+
+        try {
+            String _str = Normalizer.normalize(str, Normalizer.Form.NFC);
+            byte _buf[] = _str.getBytes("UTF-8");
+            byte _cpy[] = new byte[_buf.length];
+            System.arraycopy(_buf,0,_cpy,0,_buf.length);
+            return _cpy;
+        }
+        catch (UnsupportedEncodingException e) {
+            assert false;
+            return new byte[0];
+        }
+    }
+
+    public static Vector<byte[]> toUTF8(Vector<String> list) {
+        if (list == null)
+            return null;
+
+        Vector<byte[]> result = new Vector<byte[]>(list.size());
+
+        for (int i=0; i<list.size(); i++)
+            result.add(toUTF8(list.get(i)));
+
+        return result;
+    }
+
+    public static Pair<byte[], byte[]> toUTF8(Pair<String, String> pair) {
+        if (pair == null)
+            return null;
+
+        Pair<byte[], byte[]> result = new Pair<byte[], byte[]>();
+
+        result.first = toUTF8(pair.first);
+        result.second = toUTF8(pair.second);
+
+        return result;
+    }
+
+    public static ArrayList<Pair<byte[], byte[]>> toUTF8(ArrayList<Pair<String, String>> list) {
+        if (list == null)
+            return null;
+
+        ArrayList<Pair<byte[], byte[]>> result = new ArrayList<Pair<byte[], byte[]>>(list.size());
+
+        for (int i=0; i<list.size(); i++)
+            result.set(i, toUTF8(list.get(i)));
+
+        return result;
+    }
+
+    public static String toUTF16(byte[] utf8) {
+        if (utf8 == null)
+            return null;
+
+        try {
+            byte newUtf8[] = new byte[utf8.length];
+            System.arraycopy(utf8,0,newUtf8,0,utf8.length);
+
+            return new String(newUtf8, "UTF-8");
+        }
+        catch (UnsupportedEncodingException e) {
+            assert false;
+            return new String();
+        }
+    }
+
+    public static Vector<String> toUTF16(Vector<byte[]> list) {
+        if (list == null)
+            return null;
+
+        Vector<String> result = new Vector<String>(list.size());
+
+        for (int i=0; i<list.size(); i++)
+            result.add(toUTF16(list.get(i)));
+
+        return result;
+    }
+
+    public static Pair<String, String> toUTF16(Pair<byte[], byte[]> pair) {
+        if (pair == null)
+            return null;
+
+        Pair<String, String> result = new Pair<String,String>();
+
+        result.first = toUTF16(pair.first);
+        result.second = toUTF16(pair.second);
+
+        return result;
+    }
+
+    public static ArrayList<Pair<String, String>> toUTF16(ArrayList<Pair<byte[], byte[]>> list) {
+        if (list == null)
+            return null;
+
+        ArrayList<Pair<String, String>> result = new ArrayList<Pair<String, String>>(list.size());
+
+        for (int i=0; i<list.size(); i++)
+            result.set(i, toUTF16(list.get(i)));
+
+        return result;
+    }
+}
diff --git a/src/foundation/pEp/jniadapter/_Blob.java b/src/java/foundation/pEp/jniadapter/_Blob.java
similarity index 62%
rename from src/foundation/pEp/jniadapter/_Blob.java
rename to src/java/foundation/pEp/jniadapter/_Blob.java
index 4a78ea9..4922abd 100644
--- a/src/foundation/pEp/jniadapter/_Blob.java
+++ b/src/java/foundation/pEp/jniadapter/_Blob.java
@@ -1,5 +1,7 @@
 package foundation.pEp.jniadapter;
 
+import foundation.pEp.jniadapter.exceptions.*;
+
 public class _Blob {
     public byte[] data;
     public byte[] mime_type;
@@ -9,13 +11,13 @@ public class _Blob {
 
     private native byte[] _dataToXER() throws pEpException;;
     public String dataToXER() {
-        return AbstractEngine.toUTF16(_dataToXER());
+        return Utils.toUTF16(_dataToXER());
     }
 
     _Blob(Blob b) {
         data = b.data;
-        mime_type = AbstractEngine.toUTF8(b.mime_type);
-        filename = AbstractEngine.toUTF8(b.filename);
+        mime_type = Utils.toUTF8(b.mime_type);
+        filename = Utils.toUTF8(b.filename);
     }
 }
 
diff --git a/src/foundation/pEp/jniadapter/_Identity.java b/src/java/foundation/pEp/jniadapter/_Identity.java
similarity index 67%
rename from src/foundation/pEp/jniadapter/_Identity.java
rename to src/java/foundation/pEp/jniadapter/_Identity.java
index a8ff189..13144ad 100644
--- a/src/foundation/pEp/jniadapter/_Identity.java
+++ b/src/java/foundation/pEp/jniadapter/_Identity.java
@@ -19,12 +19,12 @@ public class _Identity {
     }
 
     public _Identity(Identity i) {
-        address = AbstractEngine.toUTF8(i.address);
-        fpr = AbstractEngine.toUTF8(i.fpr);
-        user_id = AbstractEngine.toUTF8(i.user_id);
-        username = AbstractEngine.toUTF8(i.username);
+        address = Utils.toUTF8(i.address);
+        fpr = Utils.toUTF8(i.fpr);
+        user_id = Utils.toUTF8(i.user_id);
+        username = Utils.toUTF8(i.username);
         comm_type = i.comm_type.value;
-        lang = AbstractEngine.toUTF8(i.lang);
+        lang = Utils.toUTF8(i.lang);
         me = i.me;
         flags = i.flags;
     }
diff --git a/src/java/foundation/pEp/jniadapter/decrypt_message_Return.java b/src/java/foundation/pEp/jniadapter/decrypt_message_Return.java
new file mode 100644
index 0000000..e59aae9
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/decrypt_message_Return.java
@@ -0,0 +1,7 @@
+package foundation.pEp.jniadapter;
+
+public class decrypt_message_Return {
+    public Message dst;
+    public Rating rating;
+    public int flags;
+}
diff --git a/src/java/foundation/pEp/jniadapter/interfaces/AbstractEngineInterface.java b/src/java/foundation/pEp/jniadapter/interfaces/AbstractEngineInterface.java
new file mode 100644
index 0000000..63fb399
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/interfaces/AbstractEngineInterface.java
@@ -0,0 +1,30 @@
+package foundation.pEp.jniadapter.interfaces;
+
+import foundation.pEp.jniadapter.Message;
+import foundation.pEp.jniadapter.Sync;
+
+public interface AbstractEngineInterface extends AutoCloseable {
+    public String getVersion();
+
+    public String getProtocolVersion();
+
+    public void startKeyserverLookup();
+
+    public void stopKeyserverLookup();
+
+    public void startSync();
+
+    public void stopSync();
+
+    public boolean isSyncRunning();
+
+    public void setMessageToSendCallback(Sync.MessageToSendCallback messageToSendCallback);
+
+    public void setNotifyHandshakeCallback(Sync.NotifyHandshakeCallback notifyHandshakeCallback);
+
+    public void setNeedsFastPollCallback(Sync.NeedsFastPollCallback needsFastPollCallback);
+
+    public void setPassphraseRequiredCallback(Sync.PassphraseRequiredCallback passphraseRequiredCallback);
+
+    public Message incomingMessageFromPGPText(String pgpText, Message.EncFormat encFormat);
+}
diff --git a/src/java/foundation/pEp/jniadapter/interfaces/BlobInterface.java b/src/java/foundation/pEp/jniadapter/interfaces/BlobInterface.java
new file mode 100644
index 0000000..6a357d4
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/interfaces/BlobInterface.java
@@ -0,0 +1,5 @@
+package foundation.pEp.jniadapter.interfaces;
+
+public interface BlobInterface {
+
+}
diff --git a/src/java/foundation/pEp/jniadapter/interfaces/IdentityInterface.java b/src/java/foundation/pEp/jniadapter/interfaces/IdentityInterface.java
new file mode 100644
index 0000000..1782cd3
--- /dev/null
+++ b/src/java/foundation/pEp/jniadapter/interfaces/IdentityInterface.java
@@ -0,0 +1,7 @@
+package foundation.pEp.jniadapter.interfaces;
+
+import foundation.pEp.jniadapter.Rating;
+
+public interface IdentityInterface {
+    public Rating getRating();
+}
diff --git a/test/java/foundation/pEp/jniadapter/test/Makefile.conf b/test/java/foundation/pEp/jniadapter/test/Makefile.conf
index 0ee4a7b..71ee752 100644
--- a/test/java/foundation/pEp/jniadapter/test/Makefile.conf
+++ b/test/java/foundation/pEp/jniadapter/test/Makefile.conf
@@ -1,6 +1,7 @@
 JAVA_PKG_BASENAME=foundation.pEp.jniadapter.test
 JAVA_PKG_BASEPATH=foundation/pEp/jniadapter/test
 REPOROOT=../..
+DIST_DIR=$(REPOROOT)/dist
 JAVA_CWD=../../../../../
 JAVA_RESOURCES_DIR=../resources
 
@@ -14,9 +15,10 @@ PEP_HOME_DIR_BOB=$(JAVA_CWD)$(JAVA_PEP_HOME_DIR_BOB)
 PEP_HOME_DIR_CAROL=$(JAVA_CWD)$(JAVA_PEP_HOME_DIR_CAROL)
 PEP_HOME_DIR=$(PEP_HOME_DIR_ALICE)
 
-CLASSPATH=.:$(REPOROOT)/src
+CLASSPATH=.:$(DIST_DIR)/pEp.jar
+LD_LIB_PATH=.:$(DIST_DIR)
 
-JAVA=java -enableassertions -Xcheck:jni -cp $(CLASSPATH) -Djava.library.path=$(CLASSPATH)
+JAVA=java -enableassertions -Xcheck:jni -cp $(CLASSPATH) -Djava.library.path=$(LD_LIB_PATH)
 
 PITYTEST_DIR=../../../pitytest
 
diff --git a/test/java/foundation/pEp/jniadapter/test/basic/TestMain.java b/test/java/foundation/pEp/jniadapter/test/basic/TestMain.java
index d1f290c..12dc192 100644
--- a/test/java/foundation/pEp/jniadapter/test/basic/TestMain.java
+++ b/test/java/foundation/pEp/jniadapter/test/basic/TestMain.java
@@ -1,9 +1,6 @@
 package foundation.pEp.jniadapter.test.basic;
 
-import foundation.pEp.jniadapter.Blob;
-import foundation.pEp.jniadapter.Engine;
-import foundation.pEp.jniadapter.Identity;
-import foundation.pEp.jniadapter.Message;
+import foundation.pEp.jniadapter.*;
 import foundation.pEp.pitytest.TestSuite;
 import foundation.pEp.pitytest.TestUnit;
 import foundation.pEp.jniadapter.test.utils.AdapterBaseTestContext;
@@ -15,7 +12,7 @@ import static foundation.pEp.pitytest.TestLogger.log;
 
 class BasicTestContext extends AdapterBaseTestContext {
     Message enc;
-    Engine.decrypt_message_Return result;
+    decrypt_message_Return result;
 
     public BasicTestContext() {
         setTestContextName("BasicTestContext");
diff --git a/test/java/foundation/pEp/jniadapter/test/jni111/TestAlice.java b/test/java/foundation/pEp/jniadapter/test/jni111/TestAlice.java
index 429c361..52f0f04 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni111/TestAlice.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni111/TestAlice.java
@@ -4,6 +4,7 @@ import static foundation.pEp.pitytest.TestLogger.*;
 import static foundation.pEp.pitytest.utils.TestUtils.readKey;
 
 import foundation.pEp.jniadapter.*;
+import foundation.pEp.jniadapter.exceptions.*;
 import foundation.pEp.pitytest.*;
 import foundation.pEp.pitytest.utils.TestUtils;
 import foundation.pEp.jniadapter.test.utils.*;
diff --git a/test/java/foundation/pEp/jniadapter/test/jni114/TestAlice.java b/test/java/foundation/pEp/jniadapter/test/jni114/TestAlice.java
index e6a753a..f307984 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni114/TestAlice.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni114/TestAlice.java
@@ -5,6 +5,7 @@ import static foundation.pEp.pitytest.utils.TestUtils.readKey;
 import static foundation.pEp.pitytest.utils.TestUtils.sleep;
 
 import foundation.pEp.jniadapter.*;
+import foundation.pEp.jniadapter.exceptions.*;
 import foundation.pEp.pitytest.*;
 import foundation.pEp.pitytest.utils.TestUtils;
 import foundation.pEp.jniadapter.test.utils.*;
diff --git a/test/java/foundation/pEp/jniadapter/test/jni88/TestMain.java b/test/java/foundation/pEp/jniadapter/test/jni88/TestMain.java
index bc53fb5..68a15a6 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni88/TestMain.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni88/TestMain.java
@@ -1,5 +1,7 @@
 package foundation.pEp.jniadapter.test.jni88;
 import foundation.pEp.jniadapter.*;
+import foundation.pEp.jniadapter.exceptions.*;
+
 import java.util.Vector;
 import java.lang.Thread;
 
diff --git a/test/java/foundation/pEp/jniadapter/test/jni91/TestMain.java b/test/java/foundation/pEp/jniadapter/test/jni91/TestMain.java
index 0f01ccf..be7f75d 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni91/TestMain.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni91/TestMain.java
@@ -1,5 +1,6 @@
 package foundation.pEp.jniadapter.test.jni91;
 import foundation.pEp.jniadapter.*;
+import foundation.pEp.jniadapter.exceptions.*;
 
 import java.lang.Thread;
 
diff --git a/test/java/foundation/pEp/jniadapter/test/jni92/TestMain.java b/test/java/foundation/pEp/jniadapter/test/jni92/TestMain.java
index 5a9d3c7..62654f9 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni92/TestMain.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni92/TestMain.java
@@ -1,4 +1,5 @@
 package foundation.pEp.jniadapter.test.jni92;
+import foundation.pEp.jniadapter.exceptions.*;
 import foundation.pEp.jniadapter.test.utils.*;
 import foundation.pEp.pitytest.*;
 import foundation.pEp.jniadapter.*;
@@ -38,7 +39,7 @@ class TestMain {
         Engine e;
         TestLogger.logH2("Creating new Engine");
         e = new Engine();
-        TestLogger.log("Engine created with java object ID: " + e.getId());
+//        TestLogger.log("Engine created with java object ID: " + e.getId());
         return e;
     }
 
@@ -52,7 +53,7 @@ class TestMain {
 
     public static void engineConsumer(Vector<Engine> ev, Consumer<Engine> ec) {
         ev.forEach(e -> {
-            TestLogger.logH2("engineConsumer: on engine java object ID: " + e.getId());
+//            TestLogger.logH2("engineConsumer: on engine java object ID: " + e.getId());
             ec.accept(e);
         });
     }
diff --git a/test/java/foundation/pEp/jniadapter/test/jni98/TestMain.java b/test/java/foundation/pEp/jniadapter/test/jni98/TestMain.java
index a8327e1..aad0166 100644
--- a/test/java/foundation/pEp/jniadapter/test/jni98/TestMain.java
+++ b/test/java/foundation/pEp/jniadapter/test/jni98/TestMain.java
@@ -1,6 +1,6 @@
 package foundation.pEp.jniadapter.test.jni98;
 
-import foundation.pEp.jniadapter.Engine;
+import foundation.pEp.jniadapter.*;
 import foundation.pEp.jniadapter.Message;
 import foundation.pEp.pitytest.TestUnit;
 import foundation.pEp.jniadapter.test.utils.AdapterBaseTestContext;
@@ -34,7 +34,7 @@ class TestMain {
             log("\n" + msgToString(msg1, false));
 
             // Lets get the pgpText of the msg1, and the EncFormat
-            String pgpText = Engine.toUTF16(msg1.getAttachments().elementAt(1).data);
+            String pgpText = Utils.toUTF16(msg1.getAttachments().elementAt(1).data);
             Message.EncFormat ef = msg1.getEncFormat();
             //TODO: setting encformat to 4 (PEP) but getting back 3 (PGPMIME)
 
@@ -44,7 +44,7 @@ class TestMain {
             log("\n" + msgToString(msg2, false));
 
             logH2("Verify msg2");
-            Engine.decrypt_message_Return result = null;
+            decrypt_message_Return result = null;
             result = ctx.engine.decrypt_message(msg2, ctx.vStr, 0);
             log("\n" + msgToString(result.dst, false));
         }).run();
diff --git a/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestAlice.java b/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestAlice.java
index 1cb6358..f872423 100644
--- a/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestAlice.java
+++ b/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestAlice.java
@@ -2,7 +2,7 @@ package foundation.pEp.jniadapter.test.templateAliceBob;
 
 import static foundation.pEp.pitytest.TestLogger.*;
 
-import foundation.pEp.jniadapter.Engine;
+import foundation.pEp.jniadapter.*;
 import foundation.pEp.jniadapter.Message;
 import foundation.pEp.jniadapter.test.utils.transport.fsmqmanager.FsMQMessage;
 import foundation.pEp.pitytest.*;
@@ -59,7 +59,7 @@ class TestAlice {
                     Message msgRx = Utils.deserializepEpMessage(ctx, msgRxSerialized, Message.EncFormat.PEPEncInlineEA);
                     log("ENCRYPTED IN: \n" + AdapterTestUtils.msgToString(msgRx, false));
 
-                    Engine.decrypt_message_Return result = ctx.engine.decrypt_message(msgRx, null, 0);
+                    decrypt_message_Return result = ctx.engine.decrypt_message(msgRx, null, 0);
                     log("DECRYPTED msg: \n" + AdapterTestUtils.msgToString(result.dst, false));
                     log("DECRYPTED rating:" + result.rating.toString());
                     log("DECRYPTED flags:" + result.flags);
diff --git a/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestBob.java b/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestBob.java
index c8b7afc..d5e477e 100644
--- a/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestBob.java
+++ b/test/java/foundation/pEp/jniadapter/test/templateAliceBob/TestBob.java
@@ -2,7 +2,7 @@ package foundation.pEp.jniadapter.test.templateAliceBob;
 
 import static foundation.pEp.pitytest.TestLogger.*;
 
-import foundation.pEp.jniadapter.Engine;
+import foundation.pEp.jniadapter.*;
 import foundation.pEp.jniadapter.Message;
 import foundation.pEp.jniadapter.test.utils.transport.fsmqmanager.FsMQMessage;
 import foundation.pEp.pitytest.*;
@@ -39,7 +39,7 @@ class TestBob {
                     Message msgRx = Utils.deserializepEpMessage(ctx, msgRxSerialized, Message.EncFormat.PEPEncInlineEA);
                     log("ENCRYPTED IN: \n" + AdapterTestUtils.msgToString(msgRx, false));
 
-                    Engine.decrypt_message_Return result = ctx.engine.decrypt_message(msgRx, null, 0);
+                    decrypt_message_Return result = ctx.engine.decrypt_message(msgRx, null, 0);
                     log("DECRYPTED msg: \n" + AdapterTestUtils.msgToString(result.dst, false));
                     log("DECRYPTED rating:" + result.rating.toString());
                     log("DECRYPTED flags:" + result.flags);