Keep queueing video extensions while a clip is already generating.

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

pages/index.vue

@@ -261,7 +261,6 @@
             :scripts="directorScripts"
             v-model:selected-id="directorScriptId"
             v-model:name="directorScriptName"
-            :disabled="videoBusy"
             @load="loadDirectorScript"
             @save="saveDirectorScript"
             @remove="deleteDirectorScript"
@@ -402,7 +401,6 @@
                 <button
                   type="button"
                   class="text-xs text-red-300 hover:text-red-200"
-                  :disabled="editBusy"
                   @click="removeEditPass(item.id)"
                 >
                   Remove
@@ -415,13 +413,11 @@
                 :placeholder="extraPassPlaceholder"
                 :keep-items="activeKeepPrompts"
                 :keep-heading="keepPromptHeading"
-                :disabled="editBusy"
               />
             </div>
             <button
               type="button"
               class="w-full rounded-2xl border border-dashed border-white/15 px-4 py-2.5 text-sm text-zinc-300 transition hover:border-amber-300/40 hover:text-amber-100 disabled:cursor-not-allowed disabled:opacity-50"
-              :disabled="editBusy"
               @click="queueEditPass"
             >
               {{ extraPassButtonLabel }}
@@ -521,7 +517,6 @@
               <button
                 type="button"
                 class="text-xs text-red-300 hover:text-red-200"
-                :disabled="videoBusy"
                 @click="removeQueuedExtension(item.id)"
               >
                 Remove
@@ -569,7 +564,6 @@
           <button
             type="button"
             class="w-full rounded-2xl border border-dashed border-white/15 px-4 py-2.5 text-sm text-zinc-300 transition hover:border-amber-300/40 hover:text-amber-100 disabled:cursor-not-allowed disabled:opacity-50"
-            :disabled="videoBusy"
             @click="queueExtension"
           >
             + Queue Extension
@@ -1443,11 +1437,12 @@
             <button
               type="button"
               class="w-full rounded-2xl bg-amber-400 px-4 py-2.5 text-sm font-semibold text-zinc-950 transition hover:bg-amber-300 disabled:cursor-not-allowed disabled:opacity-50"
-              :disabled="!extendPrompt.trim() || lastFrameLoading || videoBusy"
+              :disabled="!extendPrompt.trim()"
               @click="generateExtension"
             >
-              Generate Extension
+              {{ videoBusy ? 'Queue extension' : 'Generate Extension' }}
             </button>
+            <p v-if="videoBusy" class="text-xs text-zinc-500">The current job keeps running in Output. This extension waits in the job queue.</p>
           </div>
           </div>
 
@@ -5744,27 +5739,19 @@ async function openExtend(item?: LibraryClip) {
 async function generateExtension() {
   const id = clipIdFromPlayer()
   if (!id || !extendPrompt.value.trim()) return
-  const switching = videoBusy.value
+  const hideOut = hideThumbnail.value
-  statusBusy.value = false
-  videoBusy.value = true
-  watchingLibrary.value = false
-  stopListen('video')
-  videoSettledUi = false
-  progress.value = 1
-  awaitingReveal.value = false
-  concealOutput.value = hideThumbnail.value || currentClip.value?.hideThumbnail === true
-  lockedSave.value = false
-  chainStep.value = 1
-  chainTotal.value = 1
-  chainLabel.value = ''
-  overallProgress.value = 0
-  completedChainStep.value = 0
-  activeChainPlan.value = []
-  statusMessage.value = 'Extracting last frame & stitching extension...'
-  startTimer('video')
   try {
     await ensureGenerationNotifyPermission()
-    const started = await $fetch<{ jobId: string; steps: number; hideThumbnail?: boolean; folderLocked?: boolean }>('/api/extend', {
+    const started = await $fetch<{
+      jobId: string
+      studioJobId?: string
+      queued?: boolean
+      steps: number
+      hideThumbnail?: boolean
+      folderLocked?: boolean
+      width?: number
+      height?: number
+    }>('/api/extend', {
       method: 'POST',
       body: {
         clipId: id,
@@ -5776,13 +5763,40 @@ async function generateExtension() {
       }
     })
     closeExtend()
-    if (switching) toast('Switched to this extension. The other job will keep saving to the library.')
+    if (started.queued) {
-    videoJobId.value = started.jobId
+      outputStudioJobId.value = started.studioJobId || ''
-    maxStep.value = started.steps
+      outputFocus.value = 'video'
+      videoAwaitingBeast.value = true
+      statusMessage.value = 'Queued. Waiting for Beast to be free.'
+      toast('Queued behind the current job.')
+      await refreshStudioQueue()
+      return
+    }
+    statusBusy.value = false
+    videoBusy.value = true
+    watchingLibrary.value = false
+    stopListen('video')
     videoSettledUi = false
+    progress.value = 1
+    awaitingReveal.value = false
+    concealOutput.value = started.hideThumbnail === true || hideOut
+    lockedSave.value = false
+    chainStep.value = 1
+    chainTotal.value = 1
+    chainLabel.value = ''
+    overallProgress.value = 0
+    completedChainStep.value = 0
+    activeChainPlan.value = []
+    statusMessage.value = 'Extracting last frame & stitching extension...'
+    startTimer('video')
+    if (started.width && started.height) playerSize.value = { width: started.width, height: started.height }
+    videoJobId.value = started.jobId
+    outputStudioJobId.value = started.studioJobId || ''
+    maxStep.value = started.steps
     persistActiveJob('video', started.jobId, started.hideThumbnail === true || concealOutput.value, started.folderLocked === true)
     listen('video', started.jobId, started.hideThumbnail === true || concealOutput.value, started.folderLocked === true)
     void pollComfyHealth()
+    void refreshStudioQueue()
   } catch (error: any) {
     videoBusy.value = false
     statusBusy.value = false

server/api/extend.post.ts

@@ -1,44 +1,10 @@
-import { copyFileSync, existsSync, readFileSync } from 'node:fs'
+import { existsSync } from 'node:fs'
-import { join } from 'node:path'
+import { addStudioJob, kickStudioQueue, listStudioJobs, videoJobsBusy } from '~/server/utils/studioQueue'
-import { composeShotPrompt } from '~/utils/globalLocks'
+import { persistLoraFields, parsePostedLoraStack, listStudioLoras } from '~/server/utils/loras'
-import { composePromptParts } from '~/utils/promptParts'
-import { parsePostedLoraStack, listStudioLoras, persistLoraFields, ensureComfyLoraNames } from '~/server/utils/loras'
 import { readLoraStack } from '~/utils/loras'
-import { clampVideoCfg } from '~/utils/generationPresets'
+import { parseExtendDuration } from '~/server/utils/extendChain'
 import { defaultVideoSteps, isLtxWorkflow, LTX_DISABLED_MESSAGE, ltxWorkflowEnabled, parseVideoWorkflow } from '~/utils/videoModels'
 
-const SAMPLERS = new Set(['res_multistep', 'euler', 'dpmpp_2m'])
-const SCHEDULERS = new Set(['simple', 'ddim_uniform', 'sgm_uniform'])
-
-function parseExtendDuration(raw: unknown) {
-  const seconds = Number(raw)
-  if (!Number.isFinite(seconds)) return 5
-  return Math.min(120, Math.max(0.5, Math.round(seconds * 10) / 10))
-}
-
-function frameLength(seconds: number, fps: number) {
-  return Math.max(5, Math.floor(seconds * fps))
-}
-
-function parseFps(raw: unknown) {
-  const fps = Number(raw)
-  return fps === 12 || fps === 30 || fps === 24 ? fps : 24
-}
-
-function parseCfg(raw: unknown, turbo: boolean) {
-  return clampVideoCfg(raw, turbo ? 1.5 : 4)
-}
-
-function parseSampler(raw: unknown) {
-  const value = String(raw || '')
-  return SAMPLERS.has(value) ? value : 'res_multistep'
-}
-
-function parseScheduler(raw: unknown) {
-  const value = String(raw || '')
-  return SCHEDULERS.has(value) ? value : 'simple'
-}
-
 export default defineEventHandler(async (event) => {
   const body = await readBody<{ clipId?: string; prompt?: string; promptPre?: string; promptPost?: string; duration?: number; lora?: unknown; loraStack?: unknown }>(event).catch(() => ({}))
   const clipId = String(body?.clipId || '').trim()
@@ -63,222 +29,72 @@ export default defineEventHandler(async (event) => {
   const durationSeconds = parseExtendDuration(body?.duration)
   const promptPre = String(body?.promptPre ?? source.promptPre ?? '').trim()
   const promptPost = String(body?.promptPost ?? source.promptPost ?? '').trim()
-  const composedPrompt = composeShotPrompt({
-    globalLocks: source.globalLocks,
-    prompt: composePromptParts(promptPre, prompt, promptPost),
-    shotIndex: (source.chainIndex || 0) + 1,
-    familyRefs: source.permanenceRefs
-  })
   const workflow = parseVideoWorkflow(source.workflow)
   if (isLtxWorkflow(workflow) && !ltxWorkflowEnabled()) {
     throw createError({ statusCode: 400, statusMessage: LTX_DISABLED_MESSAGE })
   }
-  const turbo = source.turbo !== false
-  const fps = parseFps(source.fps)
-  const cfg = parseCfg(source.cfg, turbo)
-  const samplerName = parseSampler(source.samplerName)
-  const scheduler = parseScheduler(source.scheduler)
-  const steps = Number(source.steps || defaultVideoSteps(turbo, workflow))
-  const seed = Math.floor(Math.random() * 2_147_483_647)
   await listStudioLoras()
   const postedStack = parsePostedLoraStack(body?.loraStack ?? body?.lora, 'video')
   const loraStack = postedStack.length ? postedStack : parsePostedLoraStack(readLoraStack(source), 'video')
-  const loraFields = persistLoraFields(loraStack)
+  const familyId = source.familyId || crypto.randomUUID()
-  const length = frameLength(durationSeconds, fps)
+  const turbo = source.turbo !== false
-  const width = source.width || 1344
+  const steps = Number(source.steps || defaultVideoSteps(turbo, workflow))
-  const height = source.height || 768
+  const seed = Math.floor(Math.random() * 2_147_483_647)
-  const clipName = nextClipPartName(clipTitle(source))
 
-  const job = createJob()
+  const studio = await addStudioJob({
-  job.kind = 'video'
-  job.maxStep = steps
-  job.hideThumbnail = source.hideThumbnail
-  const tmpDir = extendTempDir(owner, job.id)
-  const part1Path = join(tmpDir, 'part1.mp4')
-  const framePath = join(tmpDir, 'last_frame.png')
-  job.library = {
     ownerKey: owner,
-    folderId: source.folderId,
+    familyId,
-    hideThumbnail: source.hideThumbnail,
+    payload: {
-    folderLocked,
+      prompt,
-    name: clipName,
+      promptMid: prompt,
-    prompt,
+      promptPre: promptPre || undefined,
-    promptMid: prompt,
+      promptPost: promptPost || undefined,
-    promptPre: promptPre || undefined,
+      name: nextClipPartName(clipTitle(source)),
-    promptPost: promptPost || undefined,
+      folderId: source.folderId,
-    aspect: source.aspect || '16:9',
+      aspect: source.aspect || '16:9',
-    width,
+      width: source.width || 1344,
-    height,
+      height: source.height || 768,
-    steps,
+      steps,
-    turbo,
+      turbo,
-    seed,
+      seed,
-    cfg,
+      cfg: Number(source.cfg || 0),
-    fps,
+      fps: Number(source.fps || 24),
-    samplerName,
+      samplerName: source.samplerName || 'res_multistep',
-    scheduler,
+      scheduler: source.scheduler || 'simple',
-    duration: durationSeconds,
+      duration: durationSeconds,
-    extendTmpDir: tmpDir,
+      sound: source.sound !== false,
-    extendPart1Path: part1Path,
+      workflow,
-    extendSourceClipId: source.id,
+      useIdentityRefs: false,
-    familyId: source.familyId || crypto.randomUUID(),
+      hideThumbnail: source.hideThumbnail,
-    parentClipId: source.id,
+      folderLocked,
-    chainIndex: (source.chainIndex || 0) + 1,
+      referenceStillIds: [null, null, null, null],
-    workflow,
+      extensions: [],
-    globalLocks: source.globalLocks,
+      queueAutoRun: false,
-    permanenceRefs: source.permanenceRefs,
+      extendFromClipId: clipId,
-    ...loraFields
+      globalLocks: source.globalLocks,
-  }
+      permanenceRefs: source.permanenceRefs,
-
+      ...persistLoraFields(loraStack)
-  emitJob(job, { type: 'status', message: 'Extracting last frame & stitching extension...', progress: 2 })
+    }
-
-  void runExtend(job, {
-    sourcePath,
-    part1Path,
-    framePath,
-    prompt: composedPrompt,
-    width,
-    height,
-    steps,
-    seed,
-    turbo,
-    length,
-    cfg,
-    fps,
-    samplerName,
-    scheduler,
-    ...loraFields
-  }).catch((error) => {
-    removeExtendTemp(job.library?.extendTmpDir)
-    const message = error instanceof Error ? error.message : String(error)
-    job.status = 'error'
-    job.error = message
-    emitJob(job, { type: 'error', error: message, message })
   })
+  await kickStudioQueue()
+  let latest = listStudioJobs(owner).find(item => item.id === studio.id)
+  if (!latest?.liveJobId && !(await videoJobsBusy())) {
+    await kickStudioQueue()
+    latest = listStudioJobs(owner).find(item => item.id === studio.id)
+  }
+  const liveJobId = latest?.liveJobId || ''
 
   return {
-    jobId: job.id,
+    jobId: liveJobId || studio.id,
-    clientId: job.clientId,
+    studioJobId: studio.id,
+    queued: !liveJobId,
+    clientId: '',
     seed,
-    width,
+    width: source.width || 1344,
-    height,
+    height: source.height || 768,
     steps,
     duration: durationSeconds,
     hideThumbnail: source.hideThumbnail,
     folderLocked
   }
 })
-
-async function runExtend(
-  job: ReturnType<typeof createJob>,
-  params: {
-    sourcePath: string
-    part1Path: string
-    framePath: string
-    prompt: string
-    width: number
-    height: number
-    steps: number
-    seed: number
-    turbo: boolean
-    length: number
-    cfg: number
-    fps: number
-    samplerName: string
-    scheduler: string
-    loraName?: string
-    loraStack?: import('~/utils/loras').LoraStackItem[]
-  }
-) {
-  copyFileSync(params.sourcePath, params.part1Path)
-  await extractLastFrame(params.sourcePath, params.framePath)
-  const frame = readFileSync(params.framePath)
-  if (!frame.length || frame.length < 64) {
-    throw new Error('Could not extract the last frame of the clip being extended')
-  }
-  if (job.library) job.library.thumb = undefined
-  const sound = await probeHasAudio(params.part1Path)
-
-  await ensureComfyReady((status) => {
-    emitJob(job, {
-      type: status.state === 'busy' ? 'busy' : 'status',
-      message: status.message,
-      progress: status.state === 'online' ? Math.max(job.progress, 3) : Math.max(job.progress, 2),
-      busy: status.state === 'busy',
-      queueRunning: status.queueRunning,
-      queuePending: status.queuePending
-    })
-  })
-
-  const done = watchComfyJob(job)
-  job.status = 'uploading'
-  emitJob(job, { type: 'status', message: 'Uploading last frame to ComfyUI...', progress: 4 })
-  const uploaded = await uploadImage({ filename: 'last_frame.png', data: frame, type: 'image/png' }, job.id)
-  if (job.library) {
-    job.library.imageName = uploaded.name
-    job.library.imageSubfolder = uploaded.subfolder
-  }
-  emitJob(job, { type: 'status', message: 'Queueing extension on MiniMax H3...', progress: 6 })
-  await waitForComfySocket(job, 4000)
-  await ensureComfyLoraNames('video')
-
-  const graph = buildWorkflow({
-    prompt: params.prompt,
-    imageName: uploaded.name,
-    width: params.width,
-    height: params.height,
-    steps: params.steps,
-    seed: params.seed,
-    turbo: params.turbo,
-    length: params.length,
-    cfg: params.cfg,
-    fps: params.fps,
-    samplerName: params.samplerName,
-    scheduler: params.scheduler,
-    filenamePrefix: comfyFilenamePrefix(),
-    sound,
-    workflow: job.library?.workflow,
-    duration: job.library?.duration,
-    loraStack: params.loraStack || job.library?.loraStack || params.loraName || job.library?.loraName
-  })
-
-  const queued = await queuePrompt(graph, job.clientId)
-  job.promptId = queued.prompt_id
-  job.status = 'running'
-  if (job.library && job.promptId) {
-    writePendingJob({
-      jobId: job.id,
-      promptId: job.promptId,
-      clientId: job.clientId,
-      ownerKey: job.library.ownerKey,
-      folderId: job.library.folderId,
-      hideThumbnail: job.library.hideThumbnail,
-      folderLocked: job.library.folderLocked,
-      name: job.library.name,
-      prompt: job.library.prompt,
-      aspect: job.library.aspect,
-      width: job.library.width,
-      height: job.library.height,
-      steps: job.library.steps,
-      turbo: job.library.turbo,
-      seed: job.library.seed,
-      startedAt: job.startedAt,
-      imageName: job.library.imageName,
-      imageSubfolder: job.library.imageSubfolder,
-      extendTmpDir: job.library.extendTmpDir,
-      extendPart1Path: job.library.extendPart1Path,
-      familyId: job.library.familyId,
-      parentClipId: job.library.parentClipId,
-      chainIndex: job.library.chainIndex,
-      stillId: job.library.stillId,
-      sound: job.library.sound,
-      workflow: job.library.workflow,
-      duration: job.library.duration,
-      globalLocks: job.library.globalLocks,
-      permanenceRefs: job.library.permanenceRefs,
-      loraName: job.library.loraName,
-      loraStack: job.library.loraStack
-    })
-  }
-  emitJob(job, { type: 'status', message: 'Job queued on ComfyUI', progress: 8 })
-  await done
-}

server/utils/extendChain.ts

@@ -0,0 +1,287 @@
+import { copyFileSync, existsSync, readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { composeShotPrompt } from '~/utils/globalLocks'
+import { composePromptParts } from '~/utils/promptParts'
+import { parsePostedLoraStack, listStudioLoras, persistLoraFields, ensureComfyLoraNames } from '~/server/utils/loras'
+import { readLoraStack } from '~/utils/loras'
+import { clampVideoCfg } from '~/utils/generationPresets'
+import { defaultVideoSteps, isLtxWorkflow, LTX_DISABLED_MESSAGE, ltxWorkflowEnabled, parseVideoWorkflow } from '~/utils/videoModels'
+import { createJob, emitJob, type Job } from '~/server/utils/jobs'
+import {
+  clipTitle,
+  clipVideoPath,
+  extendTempDir,
+  getClip,
+  nextClipPartName,
+  removeExtendTemp
+} from '~/server/utils/library'
+import { extractLastFrame, probeHasAudio } from '~/server/utils/ffmpeg'
+import { ensureComfyReady, waitForComfySocket, watchComfyJob } from '~/server/utils/comfyLifecycle'
+import { comfyFilenamePrefix, queuePrompt, uploadImage } from '~/server/utils/comfy'
+import { buildWorkflow } from '~/server/utils/workflow'
+import { writePendingJob } from '~/server/utils/pending'
+
+const SAMPLERS = new Set(['res_multistep', 'euler', 'dpmpp_2m'])
+const SCHEDULERS = new Set(['simple', 'ddim_uniform', 'sgm_uniform'])
+
+export function parseExtendDuration(raw: unknown) {
+  const seconds = Number(raw)
+  if (!Number.isFinite(seconds)) return 5
+  return Math.min(120, Math.max(0.5, Math.round(seconds * 10) / 10))
+}
+
+function frameLength(seconds: number, fps: number) {
+  return Math.max(5, Math.floor(seconds * fps))
+}
+
+function parseFps(raw: unknown) {
+  const fps = Number(raw)
+  return fps === 12 || fps === 30 || fps === 24 ? fps : 24
+}
+
+function parseCfg(raw: unknown, turbo: boolean) {
+  return clampVideoCfg(raw, turbo ? 1.5 : 4)
+}
+
+function parseSampler(raw: unknown) {
+  const value = String(raw || '')
+  return SAMPLERS.has(value) ? value : 'res_multistep'
+}
+
+function parseScheduler(raw: unknown) {
+  const value = String(raw || '')
+  return SCHEDULERS.has(value) ? value : 'simple'
+}
+
+export async function beginExtendFromClip(params: {
+  ownerKey: string
+  clipId: string
+  prompt: string
+  promptPre?: string
+  promptPost?: string
+  duration?: number
+  loraStack?: unknown
+  folderLocked?: boolean
+}) {
+  const source = getClip(params.ownerKey, params.clipId)
+  const sourcePath = clipVideoPath(params.ownerKey, source.id)
+  if (!existsSync(sourcePath)) {
+    throw createError({ statusCode: 404, statusMessage: 'Source video is missing' })
+  }
+  const prompt = String(params.prompt || '').trim()
+  if (!prompt) {
+    throw createError({ statusCode: 400, statusMessage: 'An extension prompt is required' })
+  }
+
+  const durationSeconds = parseExtendDuration(params.duration)
+  const promptPre = String(params.promptPre ?? source.promptPre ?? '').trim()
+  const promptPost = String(params.promptPost ?? source.promptPost ?? '').trim()
+  const composedPrompt = composeShotPrompt({
+    globalLocks: source.globalLocks,
+    prompt: composePromptParts(promptPre, prompt, promptPost),
+    shotIndex: (source.chainIndex || 0) + 1,
+    familyRefs: source.permanenceRefs
+  })
+  const workflow = parseVideoWorkflow(source.workflow)
+  if (isLtxWorkflow(workflow) && !ltxWorkflowEnabled()) {
+    throw createError({ statusCode: 400, statusMessage: LTX_DISABLED_MESSAGE })
+  }
+  const turbo = source.turbo !== false
+  const fps = parseFps(source.fps)
+  const cfg = parseCfg(source.cfg, turbo)
+  const samplerName = parseSampler(source.samplerName)
+  const scheduler = parseScheduler(source.scheduler)
+  const steps = Number(source.steps || defaultVideoSteps(turbo, workflow))
+  const seed = Math.floor(Math.random() * 2_147_483_647)
+  await listStudioLoras()
+  const postedStack = parsePostedLoraStack(params.loraStack, 'video')
+  const loraStack = postedStack.length ? postedStack : parsePostedLoraStack(readLoraStack(source), 'video')
+  const loraFields = persistLoraFields(loraStack)
+  const length = frameLength(durationSeconds, fps)
+  const width = source.width || 1344
+  const height = source.height || 768
+  const clipName = nextClipPartName(clipTitle(source))
+
+  const job = createJob()
+  job.kind = 'video'
+  job.maxStep = steps
+  job.hideThumbnail = source.hideThumbnail
+  const tmpDir = extendTempDir(params.ownerKey, job.id)
+  const part1Path = join(tmpDir, 'part1.mp4')
+  const framePath = join(tmpDir, 'last_frame.png')
+  job.library = {
+    ownerKey: params.ownerKey,
+    folderId: source.folderId,
+    hideThumbnail: source.hideThumbnail,
+    folderLocked: params.folderLocked,
+    name: clipName,
+    prompt,
+    promptMid: prompt,
+    promptPre: promptPre || undefined,
+    promptPost: promptPost || undefined,
+    aspect: source.aspect || '16:9',
+    width,
+    height,
+    steps,
+    turbo,
+    seed,
+    cfg,
+    fps,
+    samplerName,
+    scheduler,
+    duration: durationSeconds,
+    extendTmpDir: tmpDir,
+    extendPart1Path: part1Path,
+    extendSourceClipId: source.id,
+    familyId: source.familyId || crypto.randomUUID(),
+    parentClipId: source.id,
+    chainIndex: (source.chainIndex || 0) + 1,
+    workflow,
+    globalLocks: source.globalLocks,
+    permanenceRefs: source.permanenceRefs,
+    ...loraFields
+  }
+
+  emitJob(job, { type: 'status', message: 'Extracting last frame & stitching extension...', progress: 2 })
+
+  void runExtend(job, {
+    sourcePath,
+    part1Path,
+    framePath,
+    prompt: composedPrompt,
+    width,
+    height,
+    steps,
+    seed,
+    turbo,
+    length,
+    cfg,
+    fps,
+    samplerName,
+    scheduler,
+    ...loraFields
+  }).catch((error) => {
+    removeExtendTemp(job.library?.extendTmpDir)
+    const message = error instanceof Error ? error.message : String(error)
+    job.status = 'error'
+    job.error = message
+    emitJob(job, { type: 'error', error: message, message })
+  })
+
+  return job
+}
+
+async function runExtend(
+  job: Job,
+  params: {
+    sourcePath: string
+    part1Path: string
+    framePath: string
+    prompt: string
+    width: number
+    height: number
+    steps: number
+    seed: number
+    turbo: boolean
+    length: number
+    cfg: number
+    fps: number
+    samplerName: string
+    scheduler: string
+    loraName?: string
+    loraStack?: import('~/utils/loras').LoraStackItem[]
+  }
+) {
+  copyFileSync(params.sourcePath, params.part1Path)
+  await extractLastFrame(params.sourcePath, params.framePath)
+  const frame = readFileSync(params.framePath)
+  if (!frame.length || frame.length < 64) {
+    throw new Error('Could not extract the last frame of the clip being extended')
+  }
+  if (job.library) job.library.thumb = undefined
+  const sound = await probeHasAudio(params.part1Path)
+
+  await ensureComfyReady((status) => {
+    emitJob(job, {
+      type: status.state === 'busy' ? 'busy' : 'status',
+      message: status.message,
+      progress: status.state === 'online' ? Math.max(job.progress, 3) : Math.max(job.progress, 2),
+      busy: status.state === 'busy',
+      queueRunning: status.queueRunning,
+      queuePending: status.queuePending
+    })
+  })
+
+  const done = watchComfyJob(job)
+  job.status = 'uploading'
+  emitJob(job, { type: 'status', message: 'Uploading last frame to ComfyUI...', progress: 4 })
+  const uploaded = await uploadImage({ filename: 'last_frame.png', data: frame, type: 'image/png' }, job.id)
+  if (job.library) {
+    job.library.imageName = uploaded.name
+    job.library.imageSubfolder = uploaded.subfolder
+  }
+  emitJob(job, { type: 'status', message: 'Queueing extension on MiniMax H3...', progress: 6 })
+  await waitForComfySocket(job, 4000)
+  await ensureComfyLoraNames('video')
+
+  const graph = buildWorkflow({
+    prompt: params.prompt,
+    imageName: uploaded.name,
+    width: params.width,
+    height: params.height,
+    steps: params.steps,
+    seed: params.seed,
+    turbo: params.turbo,
+    length: params.length,
+    cfg: params.cfg,
+    fps: params.fps,
+    samplerName: params.samplerName,
+    scheduler: params.scheduler,
+    filenamePrefix: comfyFilenamePrefix(),
+    sound,
+    workflow: job.library?.workflow,
+    duration: job.library?.duration,
+    loraStack: params.loraStack || job.library?.loraStack || params.loraName || job.library?.loraName
+  })
+
+  const queued = await queuePrompt(graph, job.clientId)
+  job.promptId = queued.prompt_id
+  job.status = 'running'
+  if (job.library && job.promptId) {
+    writePendingJob({
+      jobId: job.id,
+      promptId: job.promptId,
+      clientId: job.clientId,
+      ownerKey: job.library.ownerKey,
+      folderId: job.library.folderId,
+      hideThumbnail: job.library.hideThumbnail,
+      folderLocked: job.library.folderLocked,
+      name: job.library.name,
+      prompt: job.library.prompt,
+      aspect: job.library.aspect,
+      width: job.library.width,
+      height: job.library.height,
+      steps: job.library.steps,
+      turbo: job.library.turbo,
+      seed: job.library.seed,
+      startedAt: job.startedAt,
+      imageName: job.library.imageName,
+      imageSubfolder: job.library.imageSubfolder,
+      extendTmpDir: job.library.extendTmpDir,
+      extendPart1Path: job.library.extendPart1Path,
+      familyId: job.library.familyId,
+      parentClipId: job.library.parentClipId,
+      chainIndex: job.library.chainIndex,
+      stillId: job.library.stillId,
+      sound: job.library.sound,
+      workflow: job.library.workflow,
+      duration: job.library.duration,
+      globalLocks: job.library.globalLocks,
+      permanenceRefs: job.library.permanenceRefs,
+      loraName: job.library.loraName,
+      loraStack: job.library.loraStack
+    })
+  }
+  emitJob(job, { type: 'status', message: 'Job queued on ComfyUI', progress: 8 })
+  await done
+}

server/utils/studioQueue.ts

@@ -66,6 +66,7 @@ export interface StudioJobPayload {
   maskStillId?: string
   maskStillFilename?: string
   refineStrength?: number
+  extendFromClipId?: string
 }
 
 export interface StudioJob {
@@ -897,11 +898,44 @@ async function startStudioEditJob(item: StudioJob) {
   }
 }
 
+async function startStudioExtendJob(item: StudioJob) {
+  let live: Job | undefined
+  try {
+    const { beginExtendFromClip } = await import('~/server/utils/extendChain')
+    live = await beginExtendFromClip({
+      ownerKey: item.ownerKey,
+      clipId: String(item.payload.extendFromClipId || ''),
+      prompt: item.payload.prompt,
+      promptPre: item.payload.promptPre,
+      promptPost: item.payload.promptPost,
+      duration: item.payload.duration,
+      loraStack: item.payload.loraStack || item.payload.loraName,
+      folderLocked: item.payload.folderLocked
+    })
+    await markStudioLive(item.ownerKey, item.id, live.id)
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error)
+    if (live && (live.status === 'queued' || live.status === 'uploading' || live.status === 'running')) {
+      live.status = 'error'
+      live.error = message
+    }
+    await patchStudioJob(item.ownerKey, item.id, (job) => {
+      job.status = 'error'
+      job.lastError = message
+    }).catch(() => null)
+    kickStudioQueue()
+  }
+}
+
 export async function startStudioJob(item: StudioJob) {
   if (studioJobKind(item) === 'edit') {
     await startStudioEditJob(item)
     return
   }
+  if (item.payload.extendFromClipId) {
+    await startStudioExtendJob(item)
+    return
+  }
   let live: Job | undefined
   try {
   const { createJob } = await import('~/server/utils/jobs')