diff --git a/scripts/recook.sh b/scripts/recook.sh
new file mode 100755
index 0000000..e7f9827
--- /dev/null
+++ b/scripts/recook.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+set -e
+
+if [ -z "$1" ] ; then
+	echo "Usage $0 username"
+	exit 1
+fi
+
+if [ "`whoami`" != "root" ] ; then
+	echo "Run as root"
+	exit 1
+fi
+
+USERNAME="$1"
+# Robust way to get the user's home directory on both Linux and macOS
+export BD="$(sudo -H -u "$USERNAME" sh -c 'cd && pwd')"
+
+# change to $1 user
+sudo -u "$USERNAME" sh -c "
+set -e
+
+echo sanity=2 basedir=${BD}
+
+mkdir -p \"${BD}/libwebsockets/build\" && \
+cd \"${BD}/libwebsockets/build\" && \
+git fetch https://libwebsockets.org/repo/libwebsockets +_temp:m && \
+git reset --hard m && \
+make -j12
+"
+
+# return back to root
+cd "${BD}/libwebsockets/build"
+make -j12 install
+
+# change back to $1 user
+sudo -u "$USERNAME" sh -c "
+set -e
+
+cd \"${BD}/sai/build\" && \
+git fetch https://warmcat.com/repo/sai +_temp:m && \
+git reset --hard m && \
+make -j12
+"
+
+# return back to root
+cd "${BD}/sai/build"
+make -j12 install
+
+OS=$(uname -s)
+if [ "$OS" = "Linux" ]; then
+	systemctl restart sai-builder
+elif [ "$OS" = "Darwin" ]; then
+	launchctl unload /Library/LaunchDaemons/com.warmcat.sai-builder.plist
+	launchctl load /Library/LaunchDaemons/com.warmcat.sai-builder.plist
+else
+	echo "Unknown OS: $OS. Cannot restart sai-builder."
+fi
+
+exit 0
diff --git a/src/builder/b-power.c b/src/builder/b-power.c
index d77bc1c..086f87e 100644
--- a/src/builder/b-power.c
+++ b/src/builder/b-power.c
@@ -256,8 +256,19 @@ saib_power_stay_rx(void *userobj, const uint8_t *buf, size_t len, int flags)
 	return 0;
 }
 
+static lws_ss_state_return_t
+saib_power_stay_tx(void *userobj, lws_ss_tx_ordinal_t ord, uint8_t *buf,
+		   size_t *len, int *flags)
+{
+	*len = 0;
+	*flags = LWSSS_FLAG_SOM | LWSSS_FLAG_EOM;
+
+	return LWSSSSRET_OK;
+}
+
 LWS_SS_INFO("sai_power", saib_power_stay_t)
 	.rx				= saib_power_stay_rx,
+	.tx				= saib_power_stay_tx,
 };
 
 
@@ -274,6 +285,9 @@ sul_stay_cb(lws_sorted_usec_list_t *sul)
 	if (r)
 		lwsl_ss_err(builder.ss_stay, "Unable to start stay connection (%d)", (int)r);
 
+	if (lws_ss_request_tx(builder.ss_stay))
+		lwsl_ss_warn(builder.ss_stay, "Unable to request tx");
+
 	lws_sul_schedule(builder.context, 0, &builder.sul_stay,
 			 sul_stay_cb, SAI_STAY_POLL_US);
 }
diff --git a/src/builder/b-refproxy.c b/src/builder/b-refproxy.c
index b4b6024..11bb82d 100644
--- a/src/builder/b-refproxy.c
+++ b/src/builder/b-refproxy.c
@@ -74,17 +74,17 @@ resproxy_find_by_cookie(struct sai_plat_server *spm, const char *c, size_t clen)
 static int
 saib_queue_yield_message(struct sai_plat_server *spm, const char *c, size_t len)
 {
-	char msg[256];
+	char msg[LWS_PRE + 256];
 	size_t jl;
 
 	/*
 	 * We just send the cookie to relinquish the leased resources
 	 */
-	jl = (size_t)lws_snprintf(msg, sizeof(msg),
+	jl = (size_t)lws_snprintf(msg + LWS_PRE, sizeof(msg) - LWS_PRE,
 			      "{\"schema\":\"com-warmcat-sai-resource\","
 			      "\"cookie\":\"%.*s\"}", (int)len, c);
 
-	return saib_srv_queue_tx(spm->ss, msg, jl, LWSSS_FLAG_SOM | LWSSS_FLAG_EOM);
+	return saib_srv_queue_tx(spm->ss, msg + LWS_PRE, jl, LWSSS_FLAG_SOM | LWSSS_FLAG_EOM);
 }
 
 int
@@ -205,7 +205,16 @@ callback_resproxy(struct lws *wsi, enum lws_callback_reasons reason,
 		lws_strnncpy(pss->cookie, p, al, sizeof(pss->cookie));
 		lws_dll2_add_tail(&pss->list, &spm->resource_pss_list);
 
-		return saib_srv_queue_tx(spm->ss, in, len, LWSSS_FLAG_SOM | LWSSS_FLAG_EOM);
+		{
+			int n;
+			char *buf = malloc(LWS_PRE + len);
+			if (!buf)
+				return -1;
+			memcpy(buf + LWS_PRE, in, len);
+			n = saib_srv_queue_tx(spm->ss, buf + LWS_PRE, len, LWSSS_FLAG_SOM | LWSSS_FLAG_EOM);
+			free(buf);
+			return n;
+		}
 
 	case LWS_CALLBACK_RAW_WRITEABLE:
 		if (pss->response) {
diff --git a/src/builder/b-ws-server.c b/src/builder/b-ws-server.c
index 0735e92..210ca28 100644
--- a/src/builder/b-ws-server.c
+++ b/src/builder/b-ws-server.c
@@ -121,7 +121,7 @@ saib_srv_queue_json_fragments_helper(struct lws_ss_handle *h,
 			return -1;
 		}
 
-		if (saib_srv_queue_tx(h, buf + LWS_PRE, w, ssf))
+		if (saib_srv_queue_tx(h, buf + LWS_PRE, w, ssf) < 0)
 			return -1;
 
 		ssf &= ~((unsigned int)LWSSS_FLAG_SOM);
@@ -316,48 +316,50 @@ saib_m_tx(void *userobj, lws_ss_tx_ordinal_t ord, uint8_t *buf, size_t *len,
 	  int *flags)
 {
 	struct sai_plat_server *spm = (struct sai_plat_server *)userobj;
-	int *pi = (int *)lws_buflist_get_frag_start_or_NULL(&spm->bl_to_srv), depi;
+	unsigned int *pi = (unsigned int *)lws_buflist_get_frag_start_or_NULL(&spm->bl_to_srv);
 	char som, som1, eom, final = 1;
 	size_t fsl, used;
 
 	if (!spm->bl_to_srv)
 		return LWSSSSRET_TX_DONT_SEND;
 
-	depi = *pi;
-	*pi = (*pi) & (~(LWSSS_FLAG_SOM)); /* no SOM twice even on partial */
-
-	/*
-	 * We can only issue *len at a time.
-	 *
-	 * Notice we are getting the stored flags from the START of the fragment each time.
-	 * that means we can still see the right flags stored with the fragment, even if we
-	 * have partially used the buflist frag and are partway through it.
-	 *
-	 * Ergo, only something to skip if we are at som=1.  And also notice that although
-	 * *pi will be right, after the lws_buflist..._use() api, what it points to has been
-	 * destroyed.  So we also dereference *pi into depi for use below.
-	 */
-
 	fsl = lws_buflist_next_segment_len(&spm->bl_to_srv, NULL);
 
 	lws_buflist_fragment_use(&spm->bl_to_srv, NULL, 0, &som, &eom);
 	if (som) {
+		spm->tx_flags = *pi;
 		fsl -= sizeof(int);
 		lws_buflist_fragment_use(&spm->bl_to_srv, buf, sizeof(int), &som1, &eom);
 	}
-	if (!(depi & LWSSS_FLAG_SOM))
+	if (!(spm->tx_flags & LWSSS_FLAG_SOM))
 		som = 0;
 
-	used = (size_t)lws_buflist_fragment_use(&spm->bl_to_srv, (uint8_t *)buf, *len, &som1, &eom);
-	if (!used)
-		return LWSSSSRET_TX_DONT_SEND;
+	if (fsl == 0)
+		used = 0;
+	else
+		used = (size_t)lws_buflist_fragment_use(&spm->bl_to_srv, (uint8_t *)buf, *len, &som1, &eom);
 
-	if (used < fsl || !(depi & LWSSS_FLAG_EOM))
+	if (used < fsl || !(spm->tx_flags & LWSSS_FLAG_EOM))
 		final = 0;
 
+	if (!used && !som && !final && fsl > 0)
+		return LWSSSSRET_TX_DONT_SEND;
+
 	*len = used;
 	*flags = (som ? LWSSS_FLAG_SOM : 0) | (final ? LWSSS_FLAG_EOM : 0);
 
+	if (*flags & LWSSS_FLAG_SOM) {
+		if (spm->inside_msg) {
+			lwsl_err("%s: ILLEGAL SOM! Interrupted previous message starting with: %s\n",
+				 __func__, spm->last_msg_start);
+			lwsl_hexdump_err(buf, *len);
+		}
+		lws_strnncpy(spm->last_msg_start, (const char *)buf, *len, sizeof(spm->last_msg_start));
+		spm->inside_msg = 1;
+	}
+	if (*flags & LWSSS_FLAG_EOM)
+		spm->inside_msg = 0;
+
 //	lwsl_ss_notice(spm->ss, "Sending %d builder->srv: ssflags %d", (int)*len, (int)*flags);
 //	lwsl_hexdump_notice(buf, *len);
 
diff --git a/src/common/include/private.h b/src/common/include/private.h
index 094d194..2bd1d07 100644
--- a/src/common/include/private.h
+++ b/src/common/include/private.h
@@ -493,6 +493,10 @@ typedef struct sai_plat_server {
 	int				index;  /* used to create unique build dir path */
 
 	uint16_t			retries;
+	unsigned int			tx_flags;
+
+	char				last_msg_start[128];
+	uint8_t				inside_msg;
 } sai_plat_server_t;
 
 struct sai_env {