fix(registry): handle compound subgraph node IDs, add proactive node push from graph hooks

- Handle compound node IDs (e.g. "252:0") from expanded group subgraphs
  to fix 400 Bad Request on workflows with group nodes
- Frontend proactively pushes node data via afterConfigureGraph and
  LiteGraph hooks (onNodeAdded/onNodeRemoved/graphChanged), eliminating
  WebSocket round-trip latency for most "Send to Workflow" operations
- Add content-fingerprint dedup to skip duplicate register-nodes POSTs
- Fast-path cache returns immediately when tabs are registered (including
  0-node registrations), avoiding unnecessary WS refresh cycles
- Distinguish "Empty Registry" from other errors in standalone UI toast
- Reduce WS refresh timeout 2s→0.5s, add cooldown and lock to prevent
  concurrent refresh storms
- All [LM:Registry] logs at DEBUG level

py/routes/handlers/misc_handlers.py

@@ -573,12 +573,18 @@ class NodeRegistry:
             tab_nodes[nd["unique_id"]] = nd
 
         async with self._lock:
+            prev_count = len(self._tab_nodes.get(sid, {}))
             self._tab_nodes[sid] = tab_nodes
             self._waiting_clients.discard(sid)
             if not self._waiting_clients:
                 self._ready.set()
+            total_tabs = len(self._tab_nodes)
 
-        logger.debug("Registered %s nodes from client %s", len(nodes), sid)
+        if len(nodes) != prev_count or len(nodes) > 0:
+            logger.debug(
+                "[LM:Registry] stored %s nodes (was %s) for client %s (total tabs: %s)",
+                len(nodes), prev_count, sid, total_tabs,
+            )
 
     def prepare_for_refresh(self, active_sids: list[str]) -> None:
         """Set the list of client IDs we expect to hear from during the next refresh cycle."""
@@ -601,10 +607,17 @@ class NodeRegistry:
         longer connected."""
         async with self._lock:
             # Garbage-collect stale entries (disconnected tabs)
+            stale_sids = []
             if active_sids is not None:
                 for sid in list(self._tab_nodes):
                     if sid not in active_sids:
+                        stale_sids.append(sid)
                         del self._tab_nodes[sid]
+            if stale_sids:
+                logger.debug(
+                    "[LM:Registry] GC pruned %s disconnected tabs: %s",
+                    len(stale_sids), stale_sids,
+                )
 
             merged: dict[str, dict] = {}
             tab_info: dict[str, dict] = {}
@@ -3116,6 +3129,8 @@ class NodeRegistryHandler:
         self._node_registry = node_registry
         self._prompt_server = prompt_server
         self._standalone_mode = standalone_mode
+        self._refresh_lock = asyncio.Lock()
+        self._last_slow_path_ts: float = 0.0
 
     async def register_nodes(self, request: web.Request) -> web.Response:
         try:
@@ -3162,7 +3177,12 @@ class NodeRegistryHandler:
                     )
                 graph_name = node.get("graph_name")
                 try:
-                    node["node_id"] = int(node_id)
+                    # Handle compound node IDs from expanded group subgraphs,
+                    # e.g. "252:0" → 0 (parent scope is already in graph_id)
+                    if isinstance(node_id, str) and ":" in node_id:
+                        node["node_id"] = int(node_id.rsplit(":", 1)[-1])
+                    else:
+                        node["node_id"] = int(node_id)
                 except (TypeError, ValueError):
                     return web.json_response(
                         {
@@ -3203,39 +3223,95 @@ class NodeRegistryHandler:
                     status=503,
                 )
 
-            # Snapshot of currently-connected ComfyUI tabs
-            active_sids = list(self._prompt_server.instance.sockets.keys())
-            self._node_registry.prepare_for_refresh(active_sids)
-
-            try:
-                self._prompt_server.instance.send_sync("lora_registry_refresh", {})
-                logger.debug(
-                    "Sent registry refresh request (expecting %s clients)", len(active_sids)
-                )
-            except Exception as exc:
-                logger.error("Failed to send registry refresh message: %s", exc)
-                return web.json_response(
-                    {
-                        "success": False,
-                        "error": "Communication Error",
-                        "message": f"Failed to communicate with ComfyUI frontend: {exc}",
-                    },
-                    status=500,
-                )
-
-            if not await self._node_registry.wait_for_all(timeout=2.0):
-                logger.warning(
-                    "Registry refresh timeout after 2s (%s/%s clients responded)",
-                    len(active_sids) - self._node_registry.pending_client_count,
-                    len(active_sids),
-                )
-
-            # Re-read current sockets after the wait: a tab may have connected
-            # while we were waiting, and we don't want to garbage-collect it.
             current_sids = set(self._prompt_server.instance.sockets.keys())
+
+            # Fast path: if the frontend has already pushed node data (via
+            # afterConfigureGraph / graphChanged hooks), return it immediately
+            # without triggering a WebSocket round-trip.
             registry_info = await self._node_registry.get_merged_registry(
                 active_sids=current_sids
             )
+            if registry_info["tab_count"] > 0:
+                logger.debug(
+                    "[LM:Registry] fast path: %s nodes across %s tabs %s",
+                    registry_info["node_count"],
+                    registry_info["tab_count"],
+                    dict(registry_info.get("tabs", {})),
+                )
+                return web.json_response({"success": True, "data": registry_info})
+
+            # Slow path: registry is empty — trigger refresh via WebSocket.
+            # Serialize with an async lock so concurrent callers don't all
+            # trigger separate WS refresh cycles.  The second caller will
+            # re-check the fast path and (usually) find populated data.
+            async with self._refresh_lock:
+                # Re-check after acquiring the lock — another concurrent call
+                # may have populated the cache while we were waiting.
+                registry_info = await self._node_registry.get_merged_registry(
+                    active_sids=current_sids
+                )
+                if registry_info["tab_count"] > 0:
+                    logger.debug(
+                        "[LM:Registry] fast path after lock wait: %s nodes across %s tabs",
+                        registry_info["node_count"],
+                        registry_info["tab_count"],
+                    )
+                    return web.json_response({"success": True, "data": registry_info})
+
+                # Cooldown: if the slow path ran recently (< 2 s) and
+                # returned empty, skip another WS round-trip.
+                elapsed = time.monotonic() - self._last_slow_path_ts
+                if elapsed < 2.0:
+                    logger.debug(
+                        "[LM:Registry] slow path cooldown (%.1fs since last refresh), returning empty",
+                        elapsed,
+                    )
+                    return web.json_response(
+                        {
+                            "success": False,
+                            "error": "Empty Registry",
+                            "message": "No workflow nodes found — ensure ComfyUI is open and the extension is loaded.",
+                        },
+                        status=408,
+                    )
+
+                logger.debug(
+                    "[LM:Registry] slow path: cache empty, triggering WS refresh (%s connected tabs: %s)",
+                    len(current_sids), list(current_sids)[:5],
+                )
+                active_sids = list(current_sids)
+                self._node_registry.prepare_for_refresh(active_sids)
+
+                try:
+                    self._prompt_server.instance.send_sync("lora_registry_refresh", {})
+                    logger.debug(
+                        "Sent registry refresh request (expecting %s clients)", len(active_sids)
+                    )
+                except Exception as exc:
+                    logger.error("Failed to send registry refresh message: %s", exc)
+                    return web.json_response(
+                        {
+                            "success": False,
+                            "error": "Communication Error",
+                            "message": f"Failed to communicate with ComfyUI frontend: {exc}",
+                        },
+                        status=500,
+                    )
+
+                if not await self._node_registry.wait_for_all(timeout=0.5):
+                    logger.warning(
+                        "Registry refresh timeout after 0.5s (%s/%s clients responded)",
+                        len(active_sids) - self._node_registry.pending_client_count,
+                        len(active_sids),
+                    )
+
+                # Re-read current sockets after the wait: a tab may have connected
+                # while we were waiting, and we don't want to garbage-collect it.
+                current_sids = set(self._prompt_server.instance.sockets.keys())
+                registry_info = await self._node_registry.get_merged_registry(
+                    active_sids=current_sids
+                )
+                self._last_slow_path_ts = time.monotonic()
 
             if registry_info["node_count"] == 0:
                 logger.warning("No nodes registered after refresh")

static/js/utils/uiHelpers.js

@@ -552,6 +552,8 @@ async function fetchWorkflowRegistry() {
     if (!registryData.success) {
       if (registryData.error === 'Standalone Mode Active') {
         showToast('toast.general.cannotInteractStandalone', {}, 'warning');
+      } else if (registryData.error === 'Empty Registry') {
+        showToast('uiHelpers.workflow.noSupportedNodes', {}, 'warning');
       } else {
         showToast('toast.general.failedWorkflowInfo', {}, 'error');
       }

tests/routes/test_misc_routes.py

@@ -728,6 +728,54 @@ async def test_register_nodes_includes_capabilities():
     assert stored_node["widget_names"] == ["ckpt_name"]
 
 
+@pytest.mark.asyncio
+async def test_register_nodes_accepts_compound_node_ids():
+    """Subgraph nodes from expanded group nodes have compound IDs like '252:0'."""
+    node_registry = NodeRegistry()
+    handler = NodeRegistryHandler(
+        node_registry=node_registry,
+        prompt_server=FakePromptServer,
+        standalone_mode=False,
+    )
+
+    request = FakeRequest(
+        json_data={
+            "nodes": [
+                {
+                    "node_id": "252:0",
+                    "graph_id": "252",
+                    "type": "CheckpointLoaderSimple",
+                    "title": "Checkpoint Loader (subgraph)",
+                },
+                {
+                    "node_id": "252:1",
+                    "graph_id": "252",
+                    "type": "CLIPLoader",
+                    "title": "CLIP Loader (subgraph)",
+                },
+            ],
+            "client_id": "test-client-1",
+        }
+    )
+
+    response = await handler.register_nodes(request)
+    payload = json.loads(response.text)
+
+    assert response.status == 200
+    assert payload["success"] is True
+    assert "2 nodes registered" in payload["message"]
+
+    registry = await node_registry.get_merged_registry()
+    assert registry["node_count"] == 2
+
+    nodes_map = registry["nodes"]
+    assert "252:0" in nodes_map
+    assert "252:1" in nodes_map
+    assert nodes_map["252:0"]["id"] == 0
+    assert nodes_map["252:0"]["graph_id"] == "252"
+    assert nodes_map["252:1"]["id"] == 1
+
+
 @pytest.mark.asyncio
 async def test_update_node_widget_sends_payload():
     send_calls: list[tuple[str, dict]] = []

web/comfyui/workflow_registry.js

@@ -1,8 +1,10 @@
 import { app } from "../../scripts/app.js";
 import { api } from "../../scripts/api.js";
-import { getAllGraphNodes, getNodeReference, getNodeFromGraph } from "./utils.js";
+import { getAllGraphNodes, getNodeReference, getNodeFromGraph, chainCallback } from "./utils.js";
 import { ensureLmStyles } from "./lm_styles_loader.js";
 
+const DEBOUNCE_DELAY = 500;
+
 const LORA_NODE_CLASSES = new Set([
     "Lora Loader (LoraManager)",
     "Lora Stacker (LoraManager)",
@@ -79,6 +81,7 @@ app.registerExtension({
 
     setup() {
         ensureLmStyles();
+        this._log("extension initialized, clientId=%s", api.clientId ?? api.initialClientId ?? "(pending)");
 
         api.addEventListener("lora_registry_refresh", () => {
             this.refreshRegistry();
@@ -88,10 +91,64 @@ app.registerExtension({
             this.applyWidgetUpdate(event?.detail ?? {});
         });
 
-        // React to marker changes from the Node Marker extension
         window.addEventListener("lm_marker_changed", () => {
             this.refreshRegistry();
         });
+
+        this._hookGraphChanges();
+    },
+
+    async afterConfigureGraph(_missingNodeTypes, _app) {
+        this._log("afterConfigureGraph: workflow loaded (%s missing types)", _missingNodeTypes?.length ?? 0);
+        await this.refreshRegistry();
+    },
+
+    _hookGraphChanges() {
+        const graph = app.graph;
+        if (!graph) {
+            this._log("app.graph not available, skipping proactive hooks");
+            return;
+        }
+
+        let hooksInstalled = 0;
+
+        const scheduleRefresh = (source) => {
+            if (this._debounceTimer != null) {
+                clearTimeout(this._debounceTimer);
+            }
+            this._debounceTimer = setTimeout(() => {
+                this._debounceTimer = null;
+                this.refreshRegistry();
+            }, DEBOUNCE_DELAY);
+        };
+
+        try {
+            chainCallback(graph, "onNodeAdded", () => scheduleRefresh("onNodeAdded"));
+            chainCallback(graph, "onNodeRemoved", () => scheduleRefresh("onNodeRemoved"));
+            hooksInstalled += 2;
+        } catch (e) {
+            this._log("failed to chain LiteGraph hooks: %s", e.message);
+        }
+
+        if (typeof api.addEventListener === "function") {
+            try {
+                api.addEventListener("graphChanged", () => scheduleRefresh("graphChanged"));
+                hooksInstalled += 1;
+            } catch (_e) {
+                // graphChanged may not be available on older ComfyUI versions
+            }
+        }
+
+        this._log("%s proactive hooks installed on graph", hooksInstalled);
+    },
+
+    _log(format, ...args) {
+        const ts = new Date().toISOString().slice(11, 23);
+        let msg = format;
+        for (const arg of args) {
+            msg = msg.replace(/%s/g, String(arg));
+        }
+        console.debug(`[LM:Registry ${ts}] ${msg}`);
     },
 
     async refreshRegistry() {
@@ -115,7 +172,6 @@ app.registerExtension({
                 const hasTextWidget = TEXT_CAPABLE_CLASSES.has(node.comfyClass);
                 const markerRole = node.properties?.lm_marker_role ?? null;
 
-                // Skip nodes with no relevant capability UNLESS they are marked
                 if (!supportsLora && !hasTargetWidget && !hasTextWidget && !markerRole) {
                     continue;
                 }
@@ -146,6 +202,17 @@ app.registerExtension({
                 });
             }
 
+            const clientId = api.clientId ?? api.initialClientId ?? "";
+
+            // Content-based dedup: skip POST if identical to last sent payload.
+            const fingerprint = JSON.stringify(
+                workflowNodes.map(n => `${n.graph_id}:${n.node_id}|${n.marker_role ?? ""}|${n.mode ?? 0}`).sort()
+            );
+            if (fingerprint === this._lastFingerprint) {
+                return;
+            }
+            this._lastFingerprint = fingerprint;
+
             const response = await fetch("/api/lm/register-nodes", {
                 method: "POST",
                 headers: {
@@ -153,7 +220,7 @@ app.registerExtension({
                 },
                 body: JSON.stringify({
                     nodes: workflowNodes,
-                    client_id: api.clientId ?? api.initialClientId ?? "",
+                    client_id: clientId,
                 }),
             });