diff --git a/src/osax/common.h b/src/osax/common.h
index 1d827124..09120b33 100644
--- a/src/osax/common.h
+++ b/src/osax/common.h
@@ -1,7 +1,7 @@
 #ifndef SA_COMMON_H
 #define SA_COMMON_H
 
-#define OSAX_VERSION                "2.1.2"
+#define OSAX_VERSION                "2.1.3"
 
 #define OSAX_ATTRIB_DOCK_SPACES     0x01
 #define OSAX_ATTRIB_DPPM            0x02
diff --git a/src/osax/payload.m b/src/osax/payload.m
index 19c81756..2eeb0339 100644
--- a/src/osax/payload.m
+++ b/src/osax/payload.m
@@ -837,31 +837,32 @@ static void do_window_swap_proxy_out(char *message)
 
 static void do_window_blend(char *message)
 {
-    uint32_t a_wid;
-    unpack(message, a_wid);
-    if (!a_wid) return;
+    int count = 0;
+    unpack(message, count);
+    if (!count) return;
 
-    uint32_t b_wid;
-    unpack(message, b_wid);
-    if (!b_wid) return;
+    CFTypeRef transaction = SLSTransactionCreate(SLSMainConnectionID());
+    pthread_mutex_lock(&window_fade_lock);
 
-    float a_alpha, b_alpha;
-    unpack(message, a_alpha);
-    unpack(message, b_alpha);
+    for (int i = 0; i < count; ++i) {
+        uint32_t wid;
+        unpack(message, wid);
 
-    pthread_mutex_lock(&window_fade_lock);
-    struct window_fade_context *context = table_find(&window_fade_table, &a_wid);
-    if (context) {
-        context->alpha = a_alpha;
-        context->duration = 0.0f;
-        __asm__ __volatile__ ("" ::: "memory");
-        context->skip = true;
+        float alpha;
+        unpack(message, alpha);
+
+        struct window_fade_context *context = table_find(&window_fade_table, &wid);
+        if (context) {
+            context->alpha = alpha;
+            context->duration = 0.0f;
+            __asm__ __volatile__ ("" ::: "memory");
+            context->skip = true;
+        }
+
+        SLSTransactionSetWindowAlpha(transaction, wid, alpha);
     }
-    pthread_mutex_unlock(&window_fade_lock);
 
-    CFTypeRef transaction = SLSTransactionCreate(SLSMainConnectionID());
-    SLSTransactionSetWindowAlpha(transaction, a_wid, a_alpha);
-    SLSTransactionSetWindowAlpha(transaction, b_wid, b_alpha);
+    pthread_mutex_unlock(&window_fade_lock);
     SLSTransactionCommit(transaction, 0);
     CFRelease(transaction);
 }
@@ -970,7 +971,7 @@ static inline bool read_message(int sockfd, char *message)
     int bytes_read    = 0;
     int bytes_to_read = 0;
 
-    if (read(sockfd, &bytes_to_read, sizeof(char)) == sizeof(char)) {
+    if (read(sockfd, &bytes_to_read, sizeof(int)) == sizeof(int)) {
         do {
             int cur_read = read(sockfd, message+bytes_read, bytes_to_read-bytes_read);
             if (cur_read <= 0) break;
@@ -989,7 +990,7 @@ static inline bool read_message(int sockfd, char *message)
         int sockfd = accept(daemon_sockfd, NULL, 0);
         if (sockfd == -1) continue;
 
-        char message[0x100];
+        char message[0x1000];
         if (read_message(sockfd, message)) {
             handle_message(sockfd, message);
         }
diff --git a/src/sa.h b/src/sa.h
index a23d6d90..f51ebf24 100644
--- a/src/sa.h
+++ b/src/sa.h
@@ -24,6 +24,6 @@ bool scripting_addition_scale_window(uint32_t wid, float x, float y, float w, fl
 bool scripting_addition_swap_window_proxy_in(uint32_t wid, uint32_t proxy_wid);
 bool scripting_addition_swap_window_proxy_out(uint32_t wid, uint32_t proxy_wid, float wid_alpha);
 bool scripting_addition_order_window(uint32_t a_wid, int order, uint32_t b_wid);
-bool scripting_addition_blend_alpha(uint32_t a_wid, float a_alpha, uint32_t b_wid, float b_alpha);
+bool scripting_addition_blend_alpha(uint32_t *wid, float *alpha, int count);
 
 #endif
diff --git a/src/sa.m b/src/sa.m
index 81594f6d..e4a189eb 100644
--- a/src/sa.m
+++ b/src/sa.m
@@ -242,11 +242,11 @@ static bool scripting_addition_request_handshake(char *version, uint32_t *attrib
     int sockfd;
     bool result = false;
     char rsp[BUFSIZ] = {};
-    char bytes[0x100] = { 0x01, SA_OPCODE_HANDSHAKE };
+    char bytes[0x1000] = { 0x01, 0x00, 0x00, 0x00, SA_OPCODE_HANDSHAKE };
 
     if (socket_open(&sockfd)) {
         if (socket_connect(sockfd, g_sa_socket_file)) {
-            if (send(sockfd, bytes, 2, 0) != -1) {
+            if (send(sockfd, bytes, 5, 0) != -1) {
                 int length = recv(sockfd, rsp, sizeof(rsp)-1, 0);
                 if (length <= 0) goto out;
 
@@ -271,7 +271,7 @@ static bool scripting_addition_request_handshake(char *version, uint32_t *attrib
 static int scripting_addition_perform_validation(void)
 {
     uint32_t attrib = 0;
-    char version[0x100] = {};
+    char version[0x1000] = {};
     bool is_latest_version_installed = scripting_addition_check() == 0;
 
     if (!scripting_addition_request_handshake(version, &attrib)) {
@@ -416,7 +416,10 @@ int scripting_addition_load(void)
     return result;
 }
 
-#define pack(b,v,l) memcpy(b+l, &v, sizeof(v)); l += sizeof(v)
+#define sa_payload_init() char bytes[0x1000]; int length = 1+sizeof(length)
+#define pack(v) memcpy(bytes+length, &v, sizeof(v)); length += sizeof(v)
+#define pack_header(op) *(int*)bytes = length-sizeof(length); bytes[sizeof(length)] = op
+#define sa_payload_send() scripting_addition_send_bytes(bytes, length)
 
 static bool scripting_addition_send_bytes(char *bytes, int length)
 {
@@ -440,218 +443,160 @@ static bool scripting_addition_send_bytes(char *bytes, int length)
 
 bool scripting_addition_focus_space(uint64_t sid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, sid, length);
-    bytes[1] = SA_OPCODE_SPACE_FOCUS;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(sid);
+    pack_header(SA_OPCODE_SPACE_FOCUS);
+    return sa_payload_send();
 }
 
 bool scripting_addition_create_space(uint64_t sid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, sid, length);
-    bytes[1] = SA_OPCODE_SPACE_CREATE;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(sid);
+    pack_header(SA_OPCODE_SPACE_CREATE);
+    return sa_payload_send();
 }
 
 bool scripting_addition_destroy_space(uint64_t sid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, sid, length);
-    bytes[1] = SA_OPCODE_SPACE_DESTROY;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(sid);
+    pack_header(SA_OPCODE_SPACE_DESTROY);
+    return sa_payload_send();
 }
 
 bool scripting_addition_move_space_to_display(uint64_t src_sid, uint64_t dst_sid, uint64_t src_prev_sid, bool focus)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, src_sid, length);
-    pack(bytes, dst_sid, length);
-    pack(bytes, src_prev_sid, length);
-    pack(bytes, focus, length);
-    bytes[1] = SA_OPCODE_SPACE_MOVE;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(src_sid);
+    pack(dst_sid);
+    pack(src_prev_sid);
+    pack(focus);
+    pack_header(SA_OPCODE_SPACE_MOVE);
+    return sa_payload_send();
 }
 
 bool scripting_addition_move_space_after_space(uint64_t src_sid, uint64_t dst_sid, bool focus)
 {
-    char bytes[0x100];
-
-    char length = 2;
     uint64_t dummy_sid = 0;
-    pack(bytes, src_sid, length);
-    pack(bytes, dst_sid, length);
-    pack(bytes, dummy_sid, length);
-    pack(bytes, focus, length);
-    bytes[1] = SA_OPCODE_SPACE_MOVE;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(src_sid);
+    pack(dst_sid);
+    pack(dummy_sid);
+    pack(focus);
+    pack_header(SA_OPCODE_SPACE_MOVE);
+    return sa_payload_send();
 }
 
 bool scripting_addition_move_window(uint32_t wid, int x, int y)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, x, length);
-    pack(bytes, y, length);
-    bytes[1] = SA_OPCODE_WINDOW_MOVE;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(x);
+    pack(y);
+    pack_header(SA_OPCODE_WINDOW_MOVE);
+    return sa_payload_send();
 }
 
 bool scripting_addition_set_opacity(uint32_t wid, float opacity, float duration)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, opacity, length);
-    pack(bytes, duration, length);
-    bytes[1] = duration > 0 ? SA_OPCODE_WINDOW_OPACITY_FADE : SA_OPCODE_WINDOW_OPACITY;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(opacity);
+    pack(duration);
+    pack_header(duration > 0.0f ? SA_OPCODE_WINDOW_OPACITY_FADE : SA_OPCODE_WINDOW_OPACITY);
+    return sa_payload_send();
 }
 
 bool scripting_addition_set_layer(uint32_t wid, int layer)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, layer, length);
-    bytes[1] = SA_OPCODE_WINDOW_LAYER;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(layer);
+    pack_header(SA_OPCODE_WINDOW_LAYER);
+    return sa_payload_send();
 }
 
 bool scripting_addition_set_sticky(uint32_t wid, bool sticky)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, sticky, length);
-    bytes[1] = SA_OPCODE_WINDOW_STICKY;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(sticky);
+    pack_header(SA_OPCODE_WINDOW_STICKY);
+    return sa_payload_send();
 }
 
 bool scripting_addition_set_shadow(uint32_t wid, bool shadow)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, shadow, length);
-    bytes[1] = SA_OPCODE_WINDOW_SHADOW;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(shadow);
+    pack_header(SA_OPCODE_WINDOW_SHADOW);
+    return sa_payload_send();
 }
 
 bool scripting_addition_focus_window(uint32_t wid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    bytes[1] = SA_OPCODE_WINDOW_FOCUS;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack_header(SA_OPCODE_WINDOW_FOCUS);
+    return sa_payload_send();
 }
 
 bool scripting_addition_scale_window(uint32_t wid, float x, float y, float w, float h)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, x, length);
-    pack(bytes, y, length);
-    pack(bytes, w, length);
-    pack(bytes, h, length);
-    bytes[1] = SA_OPCODE_WINDOW_SCALE;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(x);
+    pack(y);
+    pack(w);
+    pack(h);
+    pack_header(SA_OPCODE_WINDOW_SCALE);
+    return sa_payload_send();
 }
 
 bool scripting_addition_swap_window_proxy_in(uint32_t wid, uint32_t proxy_wid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, proxy_wid, length);
-    bytes[1] = SA_OPCODE_WINDOW_SWAP_PROXY_IN;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(proxy_wid);
+    pack_header(SA_OPCODE_WINDOW_SWAP_PROXY_IN);
+    return sa_payload_send();
 }
 
 bool scripting_addition_swap_window_proxy_out(uint32_t wid, uint32_t proxy_wid, float wid_alpha)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, wid, length);
-    pack(bytes, proxy_wid, length);
-    pack(bytes, wid_alpha, length);
-    bytes[1] = SA_OPCODE_WINDOW_SWAP_PROXY_OUT;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(wid);
+    pack(proxy_wid);
+    pack(wid_alpha);
+    pack_header(SA_OPCODE_WINDOW_SWAP_PROXY_OUT);
+    return sa_payload_send();
 }
 
 bool scripting_addition_order_window(uint32_t a_wid, int order, uint32_t b_wid)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, a_wid, length);
-    pack(bytes, order, length);
-    pack(bytes, b_wid, length);
-    bytes[1] = SA_OPCODE_WINDOW_ORDER;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(a_wid);
+    pack(order);
+    pack(b_wid);
+    pack_header(SA_OPCODE_WINDOW_ORDER);
+    return sa_payload_send();
 }
 
-bool scripting_addition_blend_alpha(uint32_t a_wid, float a_alpha, uint32_t b_wid, float b_alpha)
+bool scripting_addition_blend_alpha(uint32_t *wid, float *alpha, int count)
 {
-    char bytes[0x100];
-
-    char length = 2;
-    pack(bytes, a_wid, length);
-    pack(bytes, b_wid, length);
-    pack(bytes, a_alpha, length);
-    pack(bytes, b_alpha, length);
-    bytes[1] = SA_OPCODE_WINDOW_BLEND;
-    bytes[0] = length-1;
-
-    return scripting_addition_send_bytes(bytes, length);
+    sa_payload_init();
+    pack(count);
+    for (int i = 0; i < count; ++i) {
+        pack(wid[i]);
+        pack(alpha[i]);
+    }
+    pack_header(SA_OPCODE_WINDOW_BLEND);
+    return sa_payload_send();
 }
+
+#undef sa_payload_init
+#undef pack
+#undef pack_header
+#undef sa_payload_send
diff --git a/src/window_manager.c b/src/window_manager.c
index 3a03bbfe..4f573530 100644
--- a/src/window_manager.c
+++ b/src/window_manager.c
@@ -584,19 +584,35 @@ static CVReturn window_manager_animate_window_list_thread_proc(CVDisplayLinkRef
         if (ft <= 0.0) ft = 0.0f;
         if (ft >= 1.0) ft = 1.0f;
 
+        int list_count = 0;
+        uint32_t wid_list[animation_count*2];
+        float  alpha_list[animation_count*2];
+
         for (int i = 0; i < animation_count; ++i) {
             if (__atomic_load_n(&context->animation_list[i].skip, __ATOMIC_RELAXED)) continue;
 
             float source_alpha = context->animation_list[i].proxy.tx;
             if (source_alpha <= 0.98f) {
-                float alpha_a = lerp(0.0f, ft, source_alpha);
-                float alpha_b = (source_alpha - alpha_a) / (1.0f - alpha_a);
-                scripting_addition_blend_alpha(context->animation_list[i].wid, alpha_a, context->animation_list[i].proxy.id, alpha_b);
+                float alpha_a            = lerp(0.0f, ft, source_alpha);
+                float alpha_b            = (source_alpha - alpha_a) / (1.0f - alpha_a);
+
+                wid_list[list_count]     = context->animation_list[i].wid;
+                alpha_list[list_count]   = alpha_a;
+
+                wid_list[list_count+1]   = context->animation_list[i].proxy.id;
+                alpha_list[list_count+1] = alpha_b;
+
+                list_count += 2;
             } else {
-                float alpha = lerp(source_alpha, ft, 0.0f);
-                scripting_addition_set_opacity(context->animation_list[i].proxy.id, alpha, 0.0f);
+                float alpha            = lerp(source_alpha, ft, 0.0f);
+
+                wid_list[list_count]   = context->animation_list[i].proxy.id;
+                alpha_list[list_count] = alpha;
+
+                ++list_count;
             }
         }
+        if (list_count) scripting_addition_blend_alpha(wid_list, alpha_list, list_count);
         if (ft != 1.0f) goto out;
 
         for (int i = 0; i < animation_count; ++i) {