Fix generation progress getting stuck at 1% after Comfy finishes.

Poll Comfy history and the job snapshot so the browser still gets the video when the live stream is buffered or the websocket misses completion.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/utils/comfy.ts

@@ -68,28 +68,63 @@ export async function fetchHistory(promptId: string) {
   return (await res.json()) as Record<string, unknown>
 }
 
-export function extractVideo(history: Record<string, unknown> | null, promptId: string) {
-  if (!history) return null
-  const entry = (history[promptId] || Object.values(history)[0]) as { outputs?: Record<string, Record<string, unknown>> } | undefined
-  const outputs = entry?.outputs || {}
-  for (const node of Object.values(outputs)) {
-    for (const key of ['videos', 'gifs', 'images', 'files']) {
-      const items = node[key]
-      if (!Array.isArray(items)) continue
-      const match = items.find((item: { filename?: string }) => String(item.filename || '').toLowerCase().endsWith('.mp4'))
-        || items[0]
-      if (match?.filename) {
-        return {
-          filename: String(match.filename),
-          subfolder: String(match.subfolder || 'video'),
-          type: String(match.type || 'output')
-        }
-      }
+function isVideoFile(item: { filename?: string; format?: string } | null | undefined) {
+  if (!item) return false
+  const name = String(item.filename || '').toLowerCase()
+  const format = String(item.format || '').toLowerCase()
+  return name.endsWith('.mp4') || name.endsWith('.webm') || format.includes('video') || format.includes('mp4')
+}
+
+function normalizeVideo(item: { filename?: string; subfolder?: string; type?: string }) {
+  return {
+    filename: String(item.filename),
+    subfolder: String(item.subfolder || ''),
+    type: String(item.type || 'output')
+  }
+}
+
+function findVideo(value: unknown, depth = 0): { filename: string; subfolder: string; type: string } | null {
+  if (!value || typeof value !== 'object' || depth > 8) return null
+  if (Array.isArray(value)) {
+    const files = value.filter((item): item is { filename?: string; format?: string; subfolder?: string; type?: string } => Boolean(item && typeof item === 'object'))
+    const match = files.find(item => String(item.filename || '').toLowerCase().endsWith('.mp4'))
+      || files.find(isVideoFile)
+    if (match?.filename) return normalizeVideo(match)
+    for (const item of value) {
+      const nested = findVideo(item, depth + 1)
+      if (nested) return nested
     }
+    return null
+  }
+  const record = value as { filename?: string; format?: string; subfolder?: string; type?: string }
+  if (record.filename && isVideoFile(record)) return normalizeVideo(record)
+  for (const nested of Object.values(value as Record<string, unknown>)) {
+    const found = findVideo(nested, depth + 1)
+    if (found) return found
   }
   return null
 }
 
+export function extractVideo(history: Record<string, unknown> | null, promptId: string) {
+  if (!history) return null
+  const entry = (history[promptId] || Object.values(history)[0]) as { outputs?: Record<string, unknown> } | undefined
+  return findVideo(entry?.outputs || {})
+}
+
+export function inspectHistory(history: Record<string, unknown> | null, promptId: string) {
+  const video = extractVideo(history, promptId)
+  if (!history) return { video: null, completed: false, error: null as string | null }
+  const entry = (history[promptId] || Object.values(history)[0]) as {
+    status?: { status_str?: string; completed?: boolean; messages?: unknown[] }
+  } | undefined
+  const status = entry?.status
+  const error = status?.status_str === 'error'
+    ? 'ComfyUI reported an execution error'
+    : null
+  const completed = Boolean(video) || status?.completed === true || status?.status_str === 'success'
+  return { video, completed, error }
+}
+
 export async function probeComfy() {
   try {
     const res = await fetch(`${comfyBase()}/system_stats`, { signal: AbortSignal.timeout(2500) })