diff --git a/src/power/p-http-api.c b/src/power/p-http-api.c
index ce294df..fc58279 100644
--- a/src/power/p-http-api.c
+++ b/src/power/p-http-api.c
@@ -183,6 +183,9 @@ LWS_SS_USER_TYPEDEF
         char                    payload[200];
         size_t                  size;
         size_t                  pos;
+	struct lws_struct_args	a;
+	struct lejp_ctx		ctx;
+	saip_builder_t		*b;
 } local_srv_t;
 
 static lws_ss_state_return_t
@@ -216,6 +219,100 @@ local_srv_tx(void *userobj, lws_ss_tx_ordinal_t ord, uint8_t *buf, size_t *len,
 }
 
 static lws_ss_state_return_t
+local_srv_rx(void *userobj, const uint8_t *buf, size_t len, int flags)
+{
+	local_srv_t *g = (local_srv_t *)userobj;
+	struct lws_ss_handle *h = lws_ss_from_user(g);
+	saip_pcon_t *pc;
+	saip_builder_t *b;
+
+	if (!g->ctx.user) { /* first time */
+		memset(&g->a, 0, sizeof(g->a));
+		g->a.map_st[0] = lsm_schema_builder_registration;
+		g->a.map_entries_st[0] = LWS_ARRAY_SIZE(lsm_schema_builder_registration);
+		g->a.ac_block_size = 2048;
+		lws_struct_json_init_parse(&g->ctx, NULL, &g->a);
+	}
+
+	if (lejp_parse(&g->ctx, buf, (int)len) < 0 || !g->a.dest) {
+		lwsl_ss_warn(h, "JSON decode failed");
+		lwsac_free(&g->a.ac);
+		return LWSSSSRET_DISCONNECT_ME;
+	}
+
+	if (g->a.top_schema_index == 0) {
+		sai_builder_registration_t *r = (sai_builder_registration_t *)g->a.dest;
+
+		lwsl_ss_notice(h, "Registered builder '%s' on pcon '%s'",
+			    r->builder_name, r->power_controller_name);
+
+		/* Find the PCON */
+		pc = saip_pcon_by_name(&power, r->power_controller_name);
+		if (!pc) {
+			lwsl_ss_warn(h, "Unknown PCON '%s', creating it", r->power_controller_name);
+			/* Dynamically create PCON if missing */
+			pc = saip_pcon_create(&power, r->power_controller_name);
+		}
+
+		if (pc) {
+			/* Check if builder already exists */
+			int found = 0;
+			lws_start_foreach_dll(struct lws_dll2 *, b_node, pc->registered_builders_owner.head) {
+				saip_builder_t *sb = lws_container_of(b_node, saip_builder_t, list);
+				if (!strcmp(sb->name, r->builder_name)) {
+					lwsl_ss_notice(h, "Builder '%s' re-connected to PCON '%s'", r->builder_name, pc->name);
+					/* sb->wsi = ...; */ /* We don't have wsi here easily, but we have SS handle? Not needed for logic. */
+					g->b = sb; /* Link user object to builder */
+					found = 1;
+					break;
+				}
+			} lws_end_foreach_dll(b_node);
+
+			if (!found) {
+				lwsl_ss_notice(h, "Adding builder '%s' to PCON '%s'", r->builder_name, pc->name);
+				b = malloc(sizeof(*b));
+				if (b) {
+					memset(b, 0, sizeof(*b));
+					lws_strncpy(b->name, r->builder_name, sizeof(b->name));
+					/* b->wsi = ...; */
+					g->b = b;
+					lws_dll2_add_tail(&b->list, &pc->registered_builders_owner);
+				} else {
+					lwsl_ss_err(h, "OOM allocating builder");
+				}
+			}
+
+			/* Store platforms */
+			if (g->b) {
+				/* Clear existing platforms first? Or just append? */
+				lws_dll2_owner_clear(&g->b->platforms_owner); /* Assuming we have a way to free items, but lwsac managed? No, these are manual. */
+				/* Actually we used lwsac for deserialization, but we need to PERSIST this data. */
+				/* We need to copy from 'r->platforms_owner' to 'g->b->platforms_owner' */
+
+				lws_start_foreach_dll(struct lws_dll2 *, p, r->platforms_owner.head) {
+					sai_builder_platform_t *bp = lws_container_of(p, sai_builder_platform_t, list);
+					saip_builder_platform_t *sbp = malloc(sizeof(*sbp));
+					if (sbp) {
+						memset(sbp, 0, sizeof(*sbp));
+						lws_strncpy(sbp->name, bp->name, sizeof(sbp->name));
+						lws_dll2_add_tail(&sbp->list, &g->b->platforms_owner);
+					}
+				} lws_end_foreach_dll(p);
+			}
+
+			/* Trigger a check since we have a new builder (it's alive!) */
+			saip_pcon_start_check();
+
+			/* Send update to sai-server */
+			saip_queue_stay_info(lws_container_of(power.sai_server_owner.head, saip_server_t, list));
+		}
+	}
+
+	lwsac_free(&g->a.ac);
+	return LWSSSSRET_OK;
+}
+
+static lws_ss_state_return_t
 local_srv_state(void *userobj, void *sh, lws_ss_constate_t state,
                lws_ss_tx_ordinal_t ack)
 {
@@ -232,6 +329,16 @@ local_srv_state(void *userobj, void *sh, lws_ss_constate_t state,
         case LWSSSCS_CREATING:
                 return lws_ss_request_tx(lws_ss_from_user(g));
 
+        case LWSSSCS_DISCONNECTED:
+		if (g->b) {
+			/* Mark as offline but don't delete */
+			/* g->b->wsi = NULL; */
+			g->b = NULL;
+		}
+		/* Clean up lejp if pending? */
+		lws_struct_json_init_parse(&g->ctx, NULL, NULL); /* Reset */
+		break;
+
         case LWSSSCS_SERVER_TXN:
 
 		lws_ss_get_metadata(lws_ss_from_user(g), "path", (const void **)&path, &len);
@@ -410,7 +517,7 @@ power_off:
 			/*
 			 * OK this is it, schedule it to happen
 			 */
-			lws_sul_schedule(lws_ss_cx_from_user(g), 0,
+			lws_sul_schedule(lws_ss_from_user(g), 0,
 						&pc->sul_delay_off,
 						saip_sul_action_power_off,
 						SAI_POWERDOWN_HOLDOFF_US);
@@ -438,5 +545,6 @@ bail:
 
 LWS_SS_INFO("local", local_srv_t)
         .tx                             = local_srv_tx,
+        .rx                             = local_srv_rx,
         .state                          = local_srv_state,
 };
diff --git a/src/power/p-private.h b/src/power/p-private.h
index fc94cc5..63013bc 100644
--- a/src/power/p-private.h
+++ b/src/power/p-private.h
@@ -93,6 +93,7 @@ typedef struct saip_pcon {
 /* Represents a builder connected to us */
 typedef struct saip_builder {
 	struct lws_dll2		list; /* in saip_pcon.registered_builders_owner */
+	lws_dll2_owner_t	platforms_owner; /* saip_builder_platform_t */
 
 	char			name[64];
 
@@ -100,6 +101,11 @@ typedef struct saip_builder {
 	struct lws		*wsi;
 } saip_builder_t;
 
+typedef struct saip_builder_platform {
+	lws_dll2_t		list;
+	char			name[64];
+} saip_builder_platform_t;
+
 
 struct saip_ws_pss;
 
diff --git a/src/power/p-sai.c b/src/power/p-sai.c
index 451a2ac..2ee1855 100644
--- a/src/power/p-sai.c
+++ b/src/power/p-sai.c
@@ -180,120 +180,8 @@ callback_std(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 static const struct lws_protocols protocol_std =
         { "protocol_std", callback_std, 0, 0 };
 
-/*
- * Builder connection handling
- */
-
-int
-callback_builder(struct lws *wsi, enum lws_callback_reasons reason,
-		 void *user, void *in, size_t len)
-{
-	struct lejp_ctx ctx;
-	lws_struct_args_t a;
-	saip_builder_t *b, **pb = (saip_builder_t **)user;
-	saip_pcon_t *pc;
-
-	switch (reason) {
-	case LWS_CALLBACK_ESTABLISHED:
-		lwsl_user("%s: builder connected\n", __func__);
-		*pb = NULL; /* Ensure user data is clean */
-		break;
-
-	case LWS_CALLBACK_RECEIVE:
-		// lwsl_hexdump_notice(in, len);
-		memset(&a, 0, sizeof(a));
-		a.map_st[0] = lsm_schema_builder_registration;
-		a.map_entries_st[0] = LWS_ARRAY_SIZE(lsm_schema_builder_registration);
-		a.ac_block_size = 2048;
-
-		lws_struct_json_init_parse(&ctx, NULL, &a);
-		if (lejp_parse(&ctx, (uint8_t *)in, (int)len) < 0 || !a.dest) {
-			lwsl_warn("%s: JSON decode failed\n", __func__);
-			lwsac_free(&a.ac);
-			return -1;
-		}
-
-		if (a.top_schema_index == 0) {
-			sai_builder_registration_t *r = (sai_builder_registration_t *)a.dest;
-
-			lwsl_notice("%s: Registered builder '%s' on pcon '%s'\n",
-				    __func__, r->builder_name, r->power_controller_name);
-
-			/* Find the PCON */
-			pc = saip_pcon_by_name(&power, r->power_controller_name);
-			if (pc) {
-				/* Check if builder already exists */
-				int found = 0;
-				lws_start_foreach_dll(struct lws_dll2 *, b_node, pc->registered_builders_owner.head) {
-					saip_builder_t *sb = lws_container_of(b_node, saip_builder_t, list);
-					if (!strcmp(sb->name, r->builder_name)) {
-						lwsl_notice("%s: Builder '%s' re-connected to PCON '%s'\n", __func__, r->builder_name, pc->name);
-						sb->wsi = wsi;
-						*pb = sb;
-						found = 1;
-						break;
-					}
-				} lws_end_foreach_dll(b_node);
-
-				if (!found) {
-					lwsl_notice("%s: Adding builder '%s' to PCON '%s'\n", __func__, r->builder_name, pc->name);
-					/* Create/Update builder entry using malloc */
-					b = malloc(sizeof(*b));
-					if (b) {
-						memset(b, 0, sizeof(*b));
-						lws_strncpy(b->name, r->builder_name, sizeof(b->name));
-						b->wsi = wsi;
-
-						/* Store pointer in user data for cleanup */
-						*pb = b;
-
-						/* Add to list */
-						lws_dll2_add_tail(&b->list, &pc->registered_builders_owner);
-					} else
-						lwsl_err("%s: OOM allocating builder\n", __func__);
-				}
-
-				/* Trigger a check since we have a new builder (it's alive!) */
-				saip_pcon_start_check();
-
-				/* Send update to sai-server? */
-				saip_queue_stay_info(lws_container_of(power.sai_server_owner.head, saip_server_t, list));
-
-			} else {
-				lwsl_err("%s: Unknown PCON '%s' for builder '%s'\n",
-					 __func__, r->power_controller_name, r->builder_name);
-			}
-
-		}
-		lwsac_free(&a.ac);
-		break;
-
-	case LWS_CALLBACK_CLOSED:
-		lwsl_user("%s: builder disconnected\n", __func__);
-		b = *pb;
-		if (b) {
-			/* Just mark it as offline, don't remove or free */
-			b->wsi = NULL;
-			/* Don't free *pb, we want to keep the struct */
-			/* *pb = NULL; */
-
-			/* Update state */
-			saip_pcon_start_check();
-		}
-		break;
-
-	default:
-		break;
-	}
-	return 0;
-}
-
-static const struct lws_protocols protocol_builder =
-        { "com-warmcat-sai-builder", callback_builder, sizeof(saip_builder_t *), 0 };
-
 static const struct lws_protocols *pprotocols[] = {
 	&protocol_std,
-	&protocol_builder,
 	NULL
 };