diff --git a/.gitmodules b/.gitmodules
index 76472bf..10474a6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
-[submodule "external/Unity"]
-	path = external/Unity
-	url = https://github.com/ThrowTheSwitch/Unity.git
+# [submodule "external/Unity"]
+# 	path = external/Unity
+# 	url = https://github.com/ThrowTheSwitch/Unity.git
+[submodule "external/cmocka"]
+	path = external/cmocka
+	url = https://git.cryptomilk.org/projects/cmocka.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9ad826f..b3c29b9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,12 +40,11 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 add_subdirectory(src) 
 
-if(TARGET_GROUP STREQUAL test)
-    include(CTest)
-
-    add_subdirectory(external)
-    add_subdirectory(test)
-endif()
+# Testing
+enable_testing()
+include(cmake/OptionsCMocka.cmake)
+add_subdirectory(external/cmocka)
+add_subdirectory(test)
 
 install(
   TARGETS zbbs-server
diff --git a/cmake/OptionsCMocka.cmake b/cmake/OptionsCMocka.cmake
new file mode 100644
index 0000000..fc1260c
--- /dev/null
+++ b/cmake/OptionsCMocka.cmake
@@ -0,0 +1,7 @@
+# Disable things we don't need from CMocka
+set(WITH_EXAMPLES OFF CACHE BOOL "Build examples" FORCE)
+set(UNIT_TESTING OFF CACHE BOOL "Build CMocka's own tests" FORCE)
+set(WITH_CMOCKERY_SUPPORT OFF CACHE BOOL "" FORCE)
+
+# Force static library (easier for most projects)
+set(WITH_STATIC_LIB ON CACHE BOOL "Build static library" FORCE)
\ No newline at end of file
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
deleted file mode 100644
index 0917251..0000000
--- a/external/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-add_library(Unity STATIC
-    Unity/src/unity.c
-)
-
-target_include_directories(Unity PUBLIC
-    Unity/src
-)
diff --git a/external/cmocka b/external/cmocka
new file mode 160000
index 0000000..7f736f6
--- /dev/null
+++ b/external/cmocka
@@ -0,0 +1 @@
+Subproject commit 7f736f65dc7e21499702d531a1de84cc5308cb7a
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8bfa26b..2c4b247 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -9,11 +9,24 @@ target_sources(zbbs-server
         ${M_SOURCES}
 )
 
+add_library(main INTERFACE)
+
+target_sources(main
+    PUBLIC
+        FILE_SET HEADERS
+        FILES
+            main.h
+)
+
+
 add_subdirectory(libs)
 add_subdirectory(db)
+add_subdirectory(components)
 
 target_link_libraries(zbbs-server 
     PRIVATE
+        session
+        client
         db
         murmur3
         OpenSSL::Crypto
diff --git a/src/components/CMakeLists.txt b/src/components/CMakeLists.txt
new file mode 100644
index 0000000..b57db15
--- /dev/null
+++ b/src/components/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_subdirectory(client)
+add_subdirectory(session)
\ No newline at end of file
diff --git a/src/components/client/CMakeLists.txt b/src/components/client/CMakeLists.txt
new file mode 100644
index 0000000..382b1d1
--- /dev/null
+++ b/src/components/client/CMakeLists.txt
@@ -0,0 +1,18 @@
+add_library(client STATIC)
+
+target_link_libraries(client 
+    PRIVATE
+        db
+        main
+        murmur3
+        OpenSSL::Crypto
+)
+
+target_sources(client
+    PRIVATE
+        client.c
+    PUBLIC
+        FILE_SET HEADERS
+        FILES
+            client.h
+)
diff --git a/src/client.c b/src/components/client/client.c
similarity index 99%
rename from src/client.c
rename to src/components/client/client.c
index 8cd7721..c78c1b3 100644
--- a/src/client.c
+++ b/src/components/client/client.c
@@ -3,7 +3,7 @@
 
 #include "client.h"
 #include "file_p.h"
-#include "main.h"
+#include <main.h>
 #include "session.h"
 #include "utils.h"
 #include <fcntl.h>
diff --git a/src/client.h b/src/components/client/client.h
similarity index 93%
rename from src/client.h
rename to src/components/client/client.h
index 711f93e..8a78960 100644
--- a/src/client.h
+++ b/src/components/client/client.h
@@ -4,7 +4,7 @@
 #ifndef CLIENT_H
 #define CLIENT_H
 
-#include "main.h"
+#include <main.h>
 void process_client_command(char *line, session *sess, server_data_t *s_d);
 void download_confirm(char *line, session *sess, server_data_t *s_d);
 #endif
\ No newline at end of file
diff --git a/src/components/session/CMakeLists.txt b/src/components/session/CMakeLists.txt
new file mode 100644
index 0000000..4fc88c6
--- /dev/null
+++ b/src/components/session/CMakeLists.txt
@@ -0,0 +1,18 @@
+add_library(session STATIC)
+
+target_link_libraries(session 
+    PRIVATE
+        client
+        db
+        murmur3
+        OpenSSL::Crypto
+)
+
+target_sources(session
+    PRIVATE
+        session.c
+    PUBLIC
+        FILE_SET HEADERS
+        FILES
+            session.h
+)
diff --git a/src/session.c b/src/components/session/session.c
similarity index 97%
rename from src/session.c
rename to src/components/session/session.c
index 24ce2ab..a46436a 100644
--- a/src/session.c
+++ b/src/components/session/session.c
@@ -2,11 +2,11 @@
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
 #include "session.h"
-#include "client.h"
-#include "file_p.h"
-#include "main.h"
-#include "user.h"
-#include "utils.h"
+#include "../../client.h"
+#include "../../file_p.h"
+#include "../../main.h"
+#include "../../user.h"
+#include "../../utils.h"
 #include <arpa/inet.h>
 #include <db.h>
 #include <fcntl.h>
diff --git a/src/session.h b/src/components/session/session.h
similarity index 96%
rename from src/session.h
rename to src/components/session/session.h
index a8e607c..3d992db 100644
--- a/src/session.h
+++ b/src/components/session/session.h
@@ -3,7 +3,7 @@
 
 #ifndef SESSION_H
 #define SESSION_H
-#include "main.h"
+#include "../../main.h"
 #include <stdio.h>
 int accept_client(int ls, session *connections[], char *wm);
 void session_send_string(struct session *sess, const char *str, ...);
diff --git a/src/user.c b/src/user.c
index 505c9af..9e4cc98 100644
--- a/src/user.c
+++ b/src/user.c
@@ -11,7 +11,6 @@
 
 int32_t create_user(session *sess, char *line) {
   i_db_user_create p;
-  int32_t privileges;
   int32_t res;
   if (sscanf(line, "register %s %s %s", p.uname, p.pass, p.email) == 3) {
     res = db_user_create(&p);
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 74826c6..a5cc086 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1 +1 @@
-add_subdirectory(file_p)
\ No newline at end of file
+add_subdirectory(session)
\ No newline at end of file
diff --git a/test/file_p/CMakeLists.txt b/test/file_p/CMakeLists.txt
deleted file mode 100644
index 0bd5e20..0000000
--- a/test/file_p/CMakeLists.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-add_executable(file_p_app
-    file_p.c
-)
-
-target_link_libraries(file_p_app
-    file_p
-    Unity
-)
-
-add_test(file_p_test file_p_app)
diff --git a/test/file_p/file_p.c b/test/file_p/file_p.c
deleted file mode 100644
index ba98c9f..0000000
--- a/test/file_p/file_p.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <unity.h>
\ No newline at end of file
diff --git a/test/session/CMakeLists.txt b/test/session/CMakeLists.txt
new file mode 100644
index 0000000..569a53a
--- /dev/null
+++ b/test/session/CMakeLists.txt
@@ -0,0 +1,12 @@
+add_executable(session_app
+    session.c
+)
+
+target_link_libraries(session_app
+    cmocka
+    session
+)
+
+target_link_options(session_app PRIVATE -Wl,--wrap=read)
+
+add_test(session_test session_app)
diff --git a/test/session/session.c b/test/session/session.c
new file mode 100644
index 0000000..a1bb0cf
--- /dev/null
+++ b/test/session/session.c
@@ -0,0 +1,35 @@
+#include <cmocka.h>
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <session.h>
+#include "../../src/main.h"
+
+#define TEST_BUF "Hello world!\n"
+
+int __wrap_read(int fd, void *buf, size_t nbytes) {
+    return sizeof TEST_BUF - 1;
+}
+ 
+void test_session_do_read(void** state) { 
+    session sess = {
+        .buf = TEST_BUF,
+        .buf_used = sizeof TEST_BUF,
+        .sd = 2,
+    };
+    char *str;
+    session_do_read(NULL, &str);
+    assert_memory_equal(str, TEST_BUF, sizeof (TEST_BUF)-1);
+}
+
+int setup(void **state) { return 0; }
+int tear_down(void **state) { return 0; }
+
+int main(int argc, char **argv) {
+  const struct CMUnitTest tests[] = {cmocka_unit_test(test_session_do_read)};
+
+  return cmocka_run_group_tests(tests, setup, tear_down);
+}