diff --git a/examples/map.c b/examples/map.c
index 57f63ae..1d1813a 100644
--- a/examples/map.c
+++ b/examples/map.c
@@ -13,8 +13,8 @@ int main(int argc, char **argv) {
         return 1;
     }
 
-    skipstone_map_set(map, 0xdead, 0xdeadbeef);
-    skipstone_map_set(map, 0xbeef, 0xcafebabe);
+    skipstone_map_set(map, 0xdead, (void *)0xdeadbeef);
+    skipstone_map_set(map, 0xbeef, (void *)0xcafebabe);
 
     printf("%p\n", skipstone_map_get(map, 0xdead));
     printf("%p\n", skipstone_map_get(map, 0xbeef));
diff --git a/examples/map.c-e b/examples/map.c-e
index 57f63ae..1d1813a 100644
--- a/examples/map.c-e
+++ b/examples/map.c-e
@@ -13,8 +13,8 @@ int main(int argc, char **argv) {
         return 1;
     }
 
-    skipstone_map_set(map, 0xdead, 0xdeadbeef);
-    skipstone_map_set(map, 0xbeef, 0xcafebabe);
+    skipstone_map_set(map, 0xdead, (void *)0xdeadbeef);
+    skipstone_map_set(map, 0xbeef, (void *)0xcafebabe);
 
     printf("%p\n", skipstone_map_get(map, 0xdead));
     printf("%p\n", skipstone_map_get(map, 0xbeef));
diff --git a/examples/music.c b/examples/music.c
index 3c8d793..5ef4d5a 100644
--- a/examples/music.c
+++ b/examples/music.c
@@ -2,7 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <skipstone/skipstone.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
 static void usage(int argc, char **argv) {
     fprintf(stderr, "usage: %s /dev/rfcommX\n", argv[0]);
@@ -10,7 +11,7 @@ static void usage(int argc, char **argv) {
 }
 
 int main(int argc, char **argv) {
-    skipstone_watch_link *link;
+    skipstone_link *link;
     void *buf;
     uint16_t len, endpoint;
 
@@ -60,20 +61,20 @@ int main(int argc, char **argv) {
         goto error_malloc_buf;
     }
 
-    if ((link = skipstone_watch_link_open_serial(argv[1])) == NULL) {
+    if ((link = skipstone_link_open_serial(argv[1])) == NULL) {
         goto error_watch_link_open;
     }
 
-    while (skipstone_recv(link, buf, &len, &endpoint) >= 0) {
+    while (skipstone_link_recv(link, buf, &len, &endpoint) >= 0) {
         printf("Received message %hu bytes for endpoint %hu\n",
             len, endpoint);
 
-        skipstone_send(link, &play_track, sizeof(play_track), 0x20);
+        skipstone_link_send(link, &play_track, sizeof(play_track), 0x20);
     }
 
-    perror("skipstone_recv()");
+    perror("skipstone_link_recv()");
 
-    skipstone_watch_link_close(link);
+    skipstone_link_close(link);
 
     return 0;
 
diff --git a/examples/music.c-e b/examples/music.c-e
index 3c8d793..5ef4d5a 100644
--- a/examples/music.c-e
+++ b/examples/music.c-e
@@ -2,7 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <skipstone/skipstone.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
 static void usage(int argc, char **argv) {
     fprintf(stderr, "usage: %s /dev/rfcommX\n", argv[0]);
@@ -10,7 +11,7 @@ static void usage(int argc, char **argv) {
 }
 
 int main(int argc, char **argv) {
-    skipstone_watch_link *link;
+    skipstone_link *link;
     void *buf;
     uint16_t len, endpoint;
 
@@ -60,20 +61,20 @@ int main(int argc, char **argv) {
         goto error_malloc_buf;
     }
 
-    if ((link = skipstone_watch_link_open_serial(argv[1])) == NULL) {
+    if ((link = skipstone_link_open_serial(argv[1])) == NULL) {
         goto error_watch_link_open;
     }
 
-    while (skipstone_recv(link, buf, &len, &endpoint) >= 0) {
+    while (skipstone_link_recv(link, buf, &len, &endpoint) >= 0) {
         printf("Received message %hu bytes for endpoint %hu\n",
             len, endpoint);
 
-        skipstone_send(link, &play_track, sizeof(play_track), 0x20);
+        skipstone_link_send(link, &play_track, sizeof(play_track), 0x20);
     }
 
-    perror("skipstone_recv()");
+    perror("skipstone_link_recv()");
 
-    skipstone_watch_link_close(link);
+    skipstone_link_close(link);
 
     return 0;
 
diff --git a/examples/read.c b/examples/read.c
index 207d23e..e5ef18e 100644
--- a/examples/read.c
+++ b/examples/read.c
@@ -2,7 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <skipstone/skipstone.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
 static void usage(int argc, char **argv) {
     fprintf(stderr, "usage: %s /dev/rfcommX\n", argv[0]);
@@ -10,7 +11,7 @@ static void usage(int argc, char **argv) {
 }
 
 int main(int argc, char **argv) {
-    skipstone_watch_link *link;
+    skipstone_link *link;
     void *buf;
     uint16_t len, endpoint;
 
@@ -22,22 +23,22 @@ int main(int argc, char **argv) {
         goto error_malloc_buf;
     }
 
-    if ((link = skipstone_watch_link_open_serial(argv[1])) == NULL) {
-        goto error_watch_link_open;
+    if ((link = skipstone_link_open_serial(argv[1])) == NULL) {
+        goto error_link_open;
     }
 
-    while (skipstone_recv(link, buf, &len, &endpoint) >= 0) {
+    while (skipstone_link_recv(link, buf, &len, &endpoint) >= 0) {
         printf("Received message %hu bytes for endpoint %hu\n",
             len, endpoint);
     }
 
-    perror("skipstone_recv()");
+    perror("skipstone_link_recv()");
 
-    skipstone_watch_link_close(link);
+    skipstone_link_close(link);
 
     return 0;
 
-error_watch_link_open:
+error_link_open:
     free(buf);
 
 error_malloc_buf:
diff --git a/examples/read.c-e b/examples/read.c-e
index 207d23e..e5ef18e 100644
--- a/examples/read.c-e
+++ b/examples/read.c-e
@@ -2,7 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <skipstone/skipstone.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
 static void usage(int argc, char **argv) {
     fprintf(stderr, "usage: %s /dev/rfcommX\n", argv[0]);
@@ -10,7 +11,7 @@ static void usage(int argc, char **argv) {
 }
 
 int main(int argc, char **argv) {
-    skipstone_watch_link *link;
+    skipstone_link *link;
     void *buf;
     uint16_t len, endpoint;
 
@@ -22,22 +23,22 @@ int main(int argc, char **argv) {
         goto error_malloc_buf;
     }
 
-    if ((link = skipstone_watch_link_open_serial(argv[1])) == NULL) {
-        goto error_watch_link_open;
+    if ((link = skipstone_link_open_serial(argv[1])) == NULL) {
+        goto error_link_open;
     }
 
-    while (skipstone_recv(link, buf, &len, &endpoint) >= 0) {
+    while (skipstone_link_recv(link, buf, &len, &endpoint) >= 0) {
         printf("Received message %hu bytes for endpoint %hu\n",
             len, endpoint);
     }
 
-    perror("skipstone_recv()");
+    perror("skipstone_link_recv()");
 
-    skipstone_watch_link_close(link);
+    skipstone_link_close(link);
 
     return 0;
 
-error_watch_link_open:
+error_link_open:
     free(buf);
 
 error_malloc_buf:
diff --git a/include/skipstone/link.h b/include/skipstone/link.h
new file mode 100644
index 0000000..5361749
--- /dev/null
+++ b/include/skipstone/link.h
@@ -0,0 +1,18 @@
+#ifndef _SKIPSTONE_LINK_H
+#define _SKIPSTONE_LINK_H
+
+#include <stdint.h>
+
+typedef struct _skipstone_link skipstone_link;
+
+skipstone_link *skipstone_link_open_serial(const char *device);
+
+int skipstone_link_close(skipstone_link *link);
+
+int skipstone_link_send(skipstone_link *link,
+    void *buf, uint16_t size, uint16_t endpoint);
+
+int skipstone_link_recv(skipstone_link *link,
+    void *buf, uint16_t *size, uint16_t *endpoint);
+
+#endif /* _SKIPSTONE_LINK_H */
diff --git a/include/skipstone/map.h b/include/skipstone/map.h
index cba2b85..4b44577 100644
--- a/include/skipstone/map.h
+++ b/include/skipstone/map.h
@@ -19,6 +19,6 @@ void skipstone_map_destroy(skipstone_map *map);
 
 void *skipstone_map_get(skipstone_map *map, uint16_t index);
 
-void *skipstone_map_set(skipstone_map *map, uint16_t index, void *value);
+int skipstone_map_set(skipstone_map *map, uint16_t index, void *value);
 
 #endif /* _SKIPSTONE_MAP_H */
diff --git a/include/skipstone/message.h b/include/skipstone/message.h
new file mode 100644
index 0000000..261c0d0
--- /dev/null
+++ b/include/skipstone/message.h
@@ -0,0 +1,38 @@
+#ifndef _SKIPSTONE_MESSAGE_H
+#define _SKIPSTONE_MESSAGE_H
+
+#include <stdint.h>
+
+#include <skipstone/link.h>
+#include <skipstone/map.h>
+
+#define SKIPSTONE_MESSAGE_MAX_PAYLOAD 4096
+
+enum {
+    SKIPSTONE_MESSAGE_ENDPOINT_NONE           =  0,
+    SKIPSTONE_MESSAGE_ENDPOINT_FIRMWARE       =  1,
+    SKIPSTONE_MESSAGE_ENDPOINT_TIME           = 11,
+    SKIPSTONE_MESSAGE_ENDPOINT_VERSIONS       = 16,
+    SKIPSTONE_MESSAGE_ENDPOINT_PHONE_VERSION  = 17,
+    SKIPSTONE_MESSAGE_ENDPOINT_SYSTEM_MESSAGE = 18,
+    SKIPSTONE_MESSAGE_ENDPOINT_MUSIC_CONTROL  = 32,
+    SKIPSTONE_MESSAGE_ENDPOINT_PHONE_CONTROL  = 33
+};
+
+typedef struct _skipstone_message_service skipstone_message_service;
+
+typedef int (*skipstone_message_handler)(skipstone_message_service *service,
+    void *buf, uint16_t size, uint16_t endpoint);
+
+skipstone_message_service *skipstone_message_service_new();
+
+int skipstone_message_service_register(skipstone_message_service *service,
+        uint16_t endpoint, skipstone_message_handler *handler, void *context);
+
+int skipstone_message_service_deregister(skipstone_message_service *service,
+        uint16_t endpoint);
+
+int skipstone_message_service_run(skipstone_message_service *service,
+        skipstone_link *link);
+
+#endif /* _SKIPSTONE_MESSAGE_H */
diff --git a/include/skipstone/queue.h b/include/skipstone/queue.h
new file mode 100644
index 0000000..825067f
--- /dev/null
+++ b/include/skipstone/queue.h
@@ -0,0 +1,16 @@
+#ifndef _SKIPSTONE_QUEUE_H
+#define _SKIPSTONE_QUEUE_H
+
+#include <sys/types.h>
+
+typedef struct _skipstone_queue skipstone_queue;
+
+skipstone_queue *skipstone_queue_new();
+
+size_t skipstone_queue_count(skipstone_queue *queue);
+
+int skipstone_queue_push(skipstone_queue *queue, void *value);
+
+int skipstone_queue_pop(skipstone_queue *queue, void **value);
+
+#endif /* _SKIPSTONE_QUEUE_H */
diff --git a/include/skipstone/skipstone.h b/include/skipstone/skipstone.h
deleted file mode 100644
index a33fefd..0000000
--- a/include/skipstone/skipstone.h
+++ /dev/null
@@ -1,49 +0,0 @@
-#ifndef _SKIPSTONE_H
-#define _SKIPSTONE_H
-
-#include <stdlib.h>
-#include <stdint.h>
-
-#define SKIPSTONE_MESSAGE_MAX_PAYLOAD 4096
-
-enum skipstone_message_endpoint {
-    SKIPSTONE_MESSAGE_ENDPOINT_NONE           =  0,
-    SKIPSTONE_MESSAGE_ENDPOINT_FIRMWARE       =  1,
-    SKIPSTONE_MESSAGE_ENDPOINT_TIME           = 11,
-    SKIPSTONE_MESSAGE_ENDPOINT_VERSIONS       = 16,
-    SKIPSTONE_MESSAGE_ENDPOINT_PHONE_VERSION  = 17,
-    SKIPSTONE_MESSAGE_ENDPOINT_SYSTEM_MESSAGE = 18,
-    SKIPSTONE_MESSAGE_ENDPOINT_MUSIC_CONTROL  = 32,
-    SKIPSTONE_MESSAGE_ENDPOINT_PHONE_CONTROL  = 33
-};
-
-typedef struct _skipstone_message_endpoint skipstone_message_endpoint;
-
-typedef struct _skipstone_watch_link skipstone_watch_link;
-
-typedef struct _skipstone_watch skipstone_watch;
-
-typedef int (*skipstone_message_handler)(skipstone_watch *watch,
-    void *buf, uint16_t size, uint16_t endpoint);
-
-skipstone_watch_link *skipstone_watch_link_open_serial(const char *device);
-
-int skipstone_watch_link_close(skipstone_watch_link *link);
-
-skipstone_watch *skipstone_watch_new(skipstone_watch_link *link);
-
-void skipstone_watch_destroy(skipstone_watch *watch);
-
-int skipstone_watch_main();
-
-void skipstone_watch_register_message_handler(skipstone_watch *watch,
-    uint16_t endpoint, skipstone_message_handler *handler, void *context);
-
-void skipstone_watch_deregister_message_handler(skipstone_watch *watch,
-    uint16_t endpoint);
-
-int skipstone_watch_link_send(skipstone_watch_link *link, void *buf, uint16_t size, uint16_t endpoint);
-
-int skipstone_watch_link_recv(skipstone_watch_link *link, void *buf, uint16_t *size, uint16_t *endpoint);
-
-#endif /* _SKIPSTONE_H */
diff --git a/include/skipstone/watch.h b/include/skipstone/watch.h
new file mode 100644
index 0000000..137c516
--- /dev/null
+++ b/include/skipstone/watch.h
@@ -0,0 +1,13 @@
+#ifndef _SKIPSTONE_WATCH_H
+#define _SKIPSTONE_WATCH_H
+
+#include <skipstone/link.h>
+#include <skipstone/message.h>
+
+typedef struct _skipstone_watch skipstone_watch;
+
+skipstone_watch *skipstone_watch_new(skipstone_link *link);
+
+void skipstone_watch_destroy(skipstone_watch *watch);
+
+#endif /* _SKIPSTONE_WATCH_H */
diff --git a/src/Makefile b/src/Makefile
index 2b673ce..f443df6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -7,9 +7,9 @@ CC		= $(CROSS)cc
 CFLAGS		+= -fPIC -I$(INCLUDE_PATH)
 LDFLAGS		=
 
-HEADERS		= skipstone.h map.h
+HEADERS		= watch.h link.h map.h message.h
 
-OBJS		= skipstone.o map.o
+OBJS		= watch.o link.o map.o message.o
 
 VERSION_MAJOR	= 0
 VERSION_MINOR	= 0.1
diff --git a/src/skipstone.c b/src/link.c
similarity index 76%
rename from src/skipstone.c
rename to src/link.c
index c3a87c2..280043d 100644
--- a/src/skipstone.c
+++ b/src/link.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <termios.h>
@@ -7,21 +8,20 @@
 #include <sys/ioctl.h>
 #include <endian.h>
 
-#include <skipstone/skipstone.h>
-#include <skipstone/map.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
-enum skipstone_watch_link_type {
+enum skipstone_link_type {
     SKIPSTONE_WATCH_LINK_SERIAL = 1
 };
 
-struct _skipstone_message_endpoint {
-    uint16_t id;
-    skipstone_message_handler *handler;
-    void *context;
+struct message_header {
+    uint16_t size,
+             endpoint;
 };
 
-struct _skipstone_watch_link {
-    enum skipstone_watch_link_type type;
+struct _skipstone_link {
+    enum skipstone_link_type type;
 
     union {
         struct {
@@ -33,18 +33,8 @@ struct _skipstone_watch_link {
     };
 };
 
-struct _skipstone_watch {
-    skipstone_watch_link *link;
-    skipstone_map *endpoints;
-};
-
-typedef struct _skipstone_message_header {
-    uint16_t size,
-             endpoint;
-} skipstone_message_header;
-
-skipstone_watch_link *skipstone_watch_link_open_serial(const char *device) {
-    skipstone_watch_link *link;
+skipstone_link *skipstone_link_open_serial(const char *device) {
+    skipstone_link *link;
 
     if ((link = malloc(sizeof(*link))) == NULL) {
         goto error_malloc_link;
@@ -91,7 +81,7 @@ error_malloc_link:
     return NULL;
 }
 
-static int _watch_link_close_serial(skipstone_watch_link *link) {
+static int _watch_link_close_serial(skipstone_link *link) {
     if (tcsetattr(link->serial.fd, TCSANOW, &link->serial.attr_old) < 0) {
         goto error_io;
     }
@@ -102,7 +92,7 @@ error_io:
     return -1;
 }
 
-int skipstone_watch_link_close(skipstone_watch_link *link) {
+int skipstone_link_close(skipstone_link *link) {
     switch (link->type) {
         case SKIPSTONE_WATCH_LINK_SERIAL: {
             return _watch_link_close_serial(link);
@@ -114,8 +104,8 @@ int skipstone_watch_link_close(skipstone_watch_link *link) {
     return -1;
 }
 
-int skipstone_watch_link_send(skipstone_watch_link *link, void *buf, uint16_t size, uint16_t endpoint) {
-    skipstone_message_header header;
+int skipstone_link_send(skipstone_link *link, void *buf, uint16_t size, uint16_t endpoint) {
+    struct message_header header;
 
     ssize_t wrlen;
 
@@ -149,8 +139,8 @@ error_toobig:
     return -1;
 }
 
-int skipstone_watch_link_recv(skipstone_watch_link *link, void *buf, uint16_t *size, uint16_t *endpoint) {
-    skipstone_message_header header;
+int skipstone_link_recv(skipstone_link *link, void *buf, uint16_t *size, uint16_t *endpoint) {
+    struct message_header header;
 
     ssize_t len_read;
      size_t len_wanted, offset = 0;
diff --git a/src/skipstone.c-e b/src/link.c-e
similarity index 76%
rename from src/skipstone.c-e
rename to src/link.c-e
index c3a87c2..280043d 100644
--- a/src/skipstone.c-e
+++ b/src/link.c-e
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <termios.h>
@@ -7,21 +8,20 @@
 #include <sys/ioctl.h>
 #include <endian.h>
 
-#include <skipstone/skipstone.h>
-#include <skipstone/map.h>
+#include <skipstone/link.h>
+#include <skipstone/message.h>
 
-enum skipstone_watch_link_type {
+enum skipstone_link_type {
     SKIPSTONE_WATCH_LINK_SERIAL = 1
 };
 
-struct _skipstone_message_endpoint {
-    uint16_t id;
-    skipstone_message_handler *handler;
-    void *context;
+struct message_header {
+    uint16_t size,
+             endpoint;
 };
 
-struct _skipstone_watch_link {
-    enum skipstone_watch_link_type type;
+struct _skipstone_link {
+    enum skipstone_link_type type;
 
     union {
         struct {
@@ -33,18 +33,8 @@ struct _skipstone_watch_link {
     };
 };
 
-struct _skipstone_watch {
-    skipstone_watch_link *link;
-    skipstone_map *endpoints;
-};
-
-typedef struct _skipstone_message_header {
-    uint16_t size,
-             endpoint;
-} skipstone_message_header;
-
-skipstone_watch_link *skipstone_watch_link_open_serial(const char *device) {
-    skipstone_watch_link *link;
+skipstone_link *skipstone_link_open_serial(const char *device) {
+    skipstone_link *link;
 
     if ((link = malloc(sizeof(*link))) == NULL) {
         goto error_malloc_link;
@@ -91,7 +81,7 @@ error_malloc_link:
     return NULL;
 }
 
-static int _watch_link_close_serial(skipstone_watch_link *link) {
+static int _watch_link_close_serial(skipstone_link *link) {
     if (tcsetattr(link->serial.fd, TCSANOW, &link->serial.attr_old) < 0) {
         goto error_io;
     }
@@ -102,7 +92,7 @@ error_io:
     return -1;
 }
 
-int skipstone_watch_link_close(skipstone_watch_link *link) {
+int skipstone_link_close(skipstone_link *link) {
     switch (link->type) {
         case SKIPSTONE_WATCH_LINK_SERIAL: {
             return _watch_link_close_serial(link);
@@ -114,8 +104,8 @@ int skipstone_watch_link_close(skipstone_watch_link *link) {
     return -1;
 }
 
-int skipstone_watch_link_send(skipstone_watch_link *link, void *buf, uint16_t size, uint16_t endpoint) {
-    skipstone_message_header header;
+int skipstone_link_send(skipstone_link *link, void *buf, uint16_t size, uint16_t endpoint) {
+    struct message_header header;
 
     ssize_t wrlen;
 
@@ -149,8 +139,8 @@ error_toobig:
     return -1;
 }
 
-int skipstone_watch_link_recv(skipstone_watch_link *link, void *buf, uint16_t *size, uint16_t *endpoint) {
-    skipstone_message_header header;
+int skipstone_link_recv(skipstone_link *link, void *buf, uint16_t *size, uint16_t *endpoint) {
+    struct message_header header;
 
     ssize_t len_read;
      size_t len_wanted, offset = 0;
diff --git a/src/map.c b/src/map.c
index f005250..3d0ce2d 100644
--- a/src/map.c
+++ b/src/map.c
@@ -54,7 +54,7 @@ void *skipstone_map_get(skipstone_map *map, uint16_t index) {
     return map[index & 0x0f].value;
 }
 
-void *skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
+int skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
     uint16_t i;
 
     for (i=0; i<SKIPSTONE_MAP_DEPTH; i++) {
@@ -72,8 +72,10 @@ void *skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
         index >>= 4;
     }
 
-    return map[index & 0x0f].value = value;
+    map[index & 0x0f].value = value;
+
+    return 0;
 
 error_new:
-    return NULL;
+    return -1;
 }
diff --git a/src/map.c-e b/src/map.c-e
index f005250..3d0ce2d 100644
--- a/src/map.c-e
+++ b/src/map.c-e
@@ -54,7 +54,7 @@ void *skipstone_map_get(skipstone_map *map, uint16_t index) {
     return map[index & 0x0f].value;
 }
 
-void *skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
+int skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
     uint16_t i;
 
     for (i=0; i<SKIPSTONE_MAP_DEPTH; i++) {
@@ -72,8 +72,10 @@ void *skipstone_map_set(skipstone_map *map, uint16_t index, void *value) {
         index >>= 4;
     }
 
-    return map[index & 0x0f].value = value;
+    map[index & 0x0f].value = value;
+
+    return 0;
 
 error_new:
-    return NULL;
+    return -1;
 }
diff --git a/src/message.c b/src/message.c
new file mode 100644
index 0000000..8ee7372
--- /dev/null
+++ b/src/message.c
@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <skipstone/link.h>
+#include <skipstone/map.h>
+#include <skipstone/queue.h>
+#include <skipstone/message.h>
+
+struct endpoint {
+    uint16_t id;
+    skipstone_message_handler *handler;
+    void *context;
+};
+
+struct _skipstone_message_service {
+    skipstone_map *endpoints;
+    skipstone_queue *pending;
+};
+
+skipstone_message_service *skipstone_message_service_new() {
+    return (skipstone_message_service *)skipstone_map_new();
+}
+
+int skipstone_message_service_register(skipstone_message_service *service,
+        uint16_t id, skipstone_message_handler *handler, void *context) {
+    struct endpoint *endpoint;
+
+    if ((endpoint = malloc(sizeof(*endpoint))) == NULL) {
+        goto error_malloc_endpoint;
+    }
+
+    endpoint->id      = id;
+    endpoint->handler = handler;
+    endpoint->context = context;
+
+    return skipstone_map_set(service->endpoints, id, endpoint);
+
+error_malloc_endpoint:
+    return -1;
+}
+
+int skipstone_message_service_deregister(skipstone_message_service *service, uint16_t id) {
+    return skipstone_map_set((skipstone_map *)service, id, NULL);
+}
+
+int skipstone_message_service_run(skipstone_message_service *service,
+        skipstone_link *link) {
+    void *buf;
+    uint16_t len, id;
+
+    if ((buf = malloc(SKIPSTONE_MESSAGE_MAX_PAYLOAD)) == NULL) {
+        goto error_malloc_buf;
+    }
+
+    while (skipstone_link_recv(link, buf, &len, &id) >= 0) {
+        printf("Received message %hu bytes for endpoint %hu\n",
+            len, id);
+    }
+
+    return 0;
+
+error_malloc_buf:
+    return -1;
+}
diff --git a/src/message.c-e b/src/message.c-e
new file mode 100644
index 0000000..8ee7372
--- /dev/null
+++ b/src/message.c-e
@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <skipstone/link.h>
+#include <skipstone/map.h>
+#include <skipstone/queue.h>
+#include <skipstone/message.h>
+
+struct endpoint {
+    uint16_t id;
+    skipstone_message_handler *handler;
+    void *context;
+};
+
+struct _skipstone_message_service {
+    skipstone_map *endpoints;
+    skipstone_queue *pending;
+};
+
+skipstone_message_service *skipstone_message_service_new() {
+    return (skipstone_message_service *)skipstone_map_new();
+}
+
+int skipstone_message_service_register(skipstone_message_service *service,
+        uint16_t id, skipstone_message_handler *handler, void *context) {
+    struct endpoint *endpoint;
+
+    if ((endpoint = malloc(sizeof(*endpoint))) == NULL) {
+        goto error_malloc_endpoint;
+    }
+
+    endpoint->id      = id;
+    endpoint->handler = handler;
+    endpoint->context = context;
+
+    return skipstone_map_set(service->endpoints, id, endpoint);
+
+error_malloc_endpoint:
+    return -1;
+}
+
+int skipstone_message_service_deregister(skipstone_message_service *service, uint16_t id) {
+    return skipstone_map_set((skipstone_map *)service, id, NULL);
+}
+
+int skipstone_message_service_run(skipstone_message_service *service,
+        skipstone_link *link) {
+    void *buf;
+    uint16_t len, id;
+
+    if ((buf = malloc(SKIPSTONE_MESSAGE_MAX_PAYLOAD)) == NULL) {
+        goto error_malloc_buf;
+    }
+
+    while (skipstone_link_recv(link, buf, &len, &id) >= 0) {
+        printf("Received message %hu bytes for endpoint %hu\n",
+            len, id);
+    }
+
+    return 0;
+
+error_malloc_buf:
+    return -1;
+}
diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 0000000..6d98d51
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,67 @@
+#include <stdlib.h>
+
+#include <skipstone/queue.h>
+
+struct entry {
+    void *value;
+    struct entry *next, *prev;
+};
+
+struct _skipstone_queue {
+    size_t count;
+    struct entry *last;
+};
+
+skipstone_queue *skipstone_queue_new() {
+    skipstone_queue *queue;
+
+    if ((queue = malloc(sizeof(*queue))) == NULL) {
+        goto error_malloc_queue;
+    }
+
+    queue->count = 0;
+    queue->last  = NULL;
+
+    return queue;
+
+error_malloc_queue:
+    return NULL;
+}
+
+size_t skipstone_queue_count(skipstone_queue *queue) {
+    return queue->count;
+}
+
+int skipstone_queue_push(skipstone_queue *queue, void *value) {
+    struct entry *next;
+
+    if ((next = malloc(sizeof(*entry))) == NULL) {
+        goto error_malloc_next;
+    }
+
+    next->value = value;
+    next->next  = NULL;
+    next->prev  = NULL;
+
+    queue->last->next = next;
+    queue->last       = next;
+
+    return 0;
+
+error_malloc_next:
+    return -1;
+}
+
+int skipstone_queue_pop(skipstone_queue *queue, void **value) {
+    struct entry *last = queue->last;
+
+    if (last == NULL) {
+        return 0;
+    }
+
+    queue->last = last->prev;
+
+    free(last);
+
+    return 0;
+}
diff --git a/src/queue.c-e b/src/queue.c-e
new file mode 100644
index 0000000..6d98d51
--- /dev/null
+++ b/src/queue.c-e
@@ -0,0 +1,67 @@
+#include <stdlib.h>
+
+#include <skipstone/queue.h>
+
+struct entry {
+    void *value;
+    struct entry *next, *prev;
+};
+
+struct _skipstone_queue {
+    size_t count;
+    struct entry *last;
+};
+
+skipstone_queue *skipstone_queue_new() {
+    skipstone_queue *queue;
+
+    if ((queue = malloc(sizeof(*queue))) == NULL) {
+        goto error_malloc_queue;
+    }
+
+    queue->count = 0;
+    queue->last  = NULL;
+
+    return queue;
+
+error_malloc_queue:
+    return NULL;
+}
+
+size_t skipstone_queue_count(skipstone_queue *queue) {
+    return queue->count;
+}
+
+int skipstone_queue_push(skipstone_queue *queue, void *value) {
+    struct entry *next;
+
+    if ((next = malloc(sizeof(*entry))) == NULL) {
+        goto error_malloc_next;
+    }
+
+    next->value = value;
+    next->next  = NULL;
+    next->prev  = NULL;
+
+    queue->last->next = next;
+    queue->last       = next;
+
+    return 0;
+
+error_malloc_next:
+    return -1;
+}
+
+int skipstone_queue_pop(skipstone_queue *queue, void **value) {
+    struct entry *last = queue->last;
+
+    if (last == NULL) {
+        return 0;
+    }
+
+    queue->last = last->prev;
+
+    free(last);
+
+    return 0;
+}
diff --git a/src/watch.c b/src/watch.c
new file mode 100644
index 0000000..6be21df
--- /dev/null
+++ b/src/watch.c
@@ -0,0 +1,41 @@
+#include <stdlib.h>
+
+#include <skipstone/watch.h>
+#include <skipstone/map.h>
+
+struct _skipstone_watch {
+    skipstone_link *link;
+    skipstone_map *endpoints;
+};
+
+struct endpoint {
+
+};
+
+skipstone_watch *skipstone_watch_new(skipstone_link *link) {
+    skipstone_watch *watch;
+
+    if ((watch = malloc(sizeof(*watch))) == NULL) {
+        goto error_malloc_watch;
+    }
+
+    if ((watch->endpoints = skipstone_map_new()) == NULL) {
+        goto error_map_new_endpoints;
+    }
+
+    watch->link = link;
+
+    return watch;
+
+error_map_new_endpoints:
+    free(watch);
+
+error_malloc_watch:
+    return NULL;
+}
+
+void skipstone_watch_destroy(skipstone_watch *watch) {
+    skipstone_map_destroy(watch->endpoints);
+
+    free(watch);
+}
diff --git a/src/watch.c-e b/src/watch.c-e
new file mode 100644
index 0000000..6be21df
--- /dev/null
+++ b/src/watch.c-e
@@ -0,0 +1,41 @@
+#include <stdlib.h>
+
+#include <skipstone/watch.h>
+#include <skipstone/map.h>
+
+struct _skipstone_watch {
+    skipstone_link *link;
+    skipstone_map *endpoints;
+};
+
+struct endpoint {
+
+};
+
+skipstone_watch *skipstone_watch_new(skipstone_link *link) {
+    skipstone_watch *watch;
+
+    if ((watch = malloc(sizeof(*watch))) == NULL) {
+        goto error_malloc_watch;
+    }
+
+    if ((watch->endpoints = skipstone_map_new()) == NULL) {
+        goto error_map_new_endpoints;
+    }
+
+    watch->link = link;
+
+    return watch;
+
+error_map_new_endpoints:
+    free(watch);
+
+error_malloc_watch:
+    return NULL;
+}
+
+void skipstone_watch_destroy(skipstone_watch *watch) {
+    skipstone_map_destroy(watch->endpoints);
+
+    free(watch);
+}