diff --git a/include/config.h b/include/config.h
index 6cf23fb..f2db461 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1,25 +1,20 @@
 /* Server */
 #define DEBUG 0
+
 #define PORT 20247
 #define MAX_NAME 32 /* Max username length */
 #define DATABASE_NAME "test.db"
-#define MAX_MESSAGE_LENGTH 8192
+#define MAX_DATA_LENGTH 8192
 
 /* Don't touch unless you know what you are doing */
-#define MAX_CONNECTION_QUEUE 128
 #define MAX_THREADS 8
-#define MAX_EVENTS 64 /* Max events can be returned simulataneouly by epoll */
 #define MAX_CLIENTS_PER_THREAD 1024
 
 /* Client */
 #define DOMAIN "127.0.0.1"
+/* #define USERNAME "night" */
 
 /* UI */
 #define PANEL_HEIGHT 1
-#define DRAW_PREVIEW 1
 
 #define CLIENT_DATA_DIR "~/.local/share/zsm/zen"
-
-/* Keybindings */
-#define DOWN 0x102
-#define UP 0x103
diff --git a/include/notification.h b/include/notification.h
index 8a81a50..448404e 100644
--- a/include/notification.h
+++ b/include/notification.h
@@ -4,6 +4,6 @@
 #include <stdint.h>
 #include <libnotify/notify.h>
 
-void send_notification(uint8_t *content);
+void send_notification(uint8_t *author, uint8_t *content);
 
 #endif
diff --git a/include/packet.h b/include/packet.h
index eba22ac..40ad798 100644
--- a/include/packet.h
+++ b/include/packet.h
@@ -26,8 +26,6 @@
 
 #include "config.h"
 
-#define ERROR_LENGTH 26
-
 #define ZSM_TYP_AUTH 0x1
 #define ZSM_TYP_MESSAGE 0x2
 #define ZSM_TYP_UPDATE_MESSAGE 0x3
@@ -51,32 +49,35 @@
 #define ZSM_STA_AUTHORISED 0xE
 
 #define ADDRESS_SIZE MAX_NAME + 1 + 255 /* 1 for @, 255 for domain, defined in RFC 5321, Section 4.5.3.1.2 */
-#define CHALLENGE_SIZE 32
 #define HASH_SIZE crypto_generichash_BYTES
 #define NONCE_SIZE crypto_aead_xchacha20poly1305_ietf_NPUBBYTES
 #define ADDITIONAL_SIZE crypto_aead_xchacha20poly1305_ietf_ABYTES
+#define MAX_MESSAGE_LENGTH MAX_DATA_LENGTH - MAX_NAME * 2 - NONCE_SIZE
 
-typedef struct packet {
+typedef struct packet_t {
     uint8_t status;
     uint8_t type;
     uint32_t length;
     uint8_t *data;
     uint8_t *signature;
-} packet;
+} packet_t;
+
+typedef struct message_t {
+	uint8_t author[MAX_NAME];
+	uint8_t recipient[MAX_NAME];
+	uint8_t *content;
+	time_t creation;
+} message_t;
 
 #include "key.h"
 
 /* Utilities functions */
-void print_packet(packet *msg);
-int recv_packet(packet *pkt, int fd, uint8_t required_type);
-packet *create_packet(uint8_t option, uint8_t type, uint32_t length, uint8_t *data, uint8_t *signature);
-int send_packet(packet *msg, int fd);
-void free_packet(packet *msg);
-int encrypt_packet(int sockfd, key_pair *kp);
-packet *verify_packet(packet *pkt, int fd);
-uint8_t *encrypt_data(uint8_t *from, uint8_t *to, uint8_t *raw, uint32_t raw_length, uint32_t *length);
-uint8_t *decrypt_data(packet *pkt);
-int verify_integrity(packet *pkt, public_key *pk);
+void print_packet(packet_t *msg);
+int recv_packet(packet_t *pkt, int fd, uint8_t required_type);
+packet_t *create_packet(uint8_t option, uint8_t type, uint32_t length, uint8_t *data, uint8_t *signature);
+int send_packet(packet_t *msg, int fd);
+void free_packet(packet_t *msg);
+int verify_packet(packet_t *pkt, int fd);
 uint8_t *create_signature(uint8_t *data, uint32_t length, secret_key *sk);
 
 #endif
diff --git a/include/server/server.h b/include/server/server.h
new file mode 100644
index 0000000..03cf135
--- /dev/null
+++ b/include/server/server.h
@@ -0,0 +1,8 @@
+#ifndef SERVER_H_
+#define SERVER_H_
+
+#define CHALLENGE_SIZE 32
+#define MAX_CONNECTION_QUEUE 128 /* for listen() */
+#define MAX_EVENTS 64 /* Max events can be returned simulataneouly by epoll */
+
+#endif
diff --git a/include/util.h b/include/util.h
index c4defb2..54e28e9 100644
--- a/include/util.h
+++ b/include/util.h
@@ -9,7 +9,6 @@
 void error(int fatal, const char *fmt, ...);
 void *memalloc(size_t size);
 void *estrdup(void *str);
-int set_nonblocking(int fd);
 char *replace_home(char *str);
 void mkdir_p(const char *destdir);
 void write_log(int type, const char *fmt, ...);