diff --git a/components/studio2/Bench.vue b/components/studio2/Bench.vue
index d650e63..5f55b0c 100644
--- a/components/studio2/Bench.vue
+++ b/components/studio2/Bench.vue
@@ -11,7 +11,7 @@
       <option v-for="f in library.folders" :key="f.id" :value="f.id">{{ f.name }}</option>
      </select>
     </label>
-    <div v-if="isClassic && form.mode!=='music'" class="flex flex-wrap items-center gap-3 text-sm text-zinc-300" aria-label="Identity locks">
+    <div v-if="isClassic && form.mode!=='music' && form.mode!=='caption'" class="flex flex-wrap items-center gap-3 text-sm text-zinc-300" aria-label="Identity locks">
      <label class="inline-flex items-center gap-1.5"><input v-model="form.lockFace" type="checkbox" class="accent-amber-400">Lock face</label>
      <label class="inline-flex items-center gap-1.5"><input v-model="form.lockOutfit" type="checkbox" class="accent-amber-400">Lock outfit</label>
     </div>
@@ -45,7 +45,7 @@
     >{{ task }}</button>
    </nav>
 
-   <div v-if="form.mode!=='music'" class="min-w-0">
+   <div v-if="form.mode!=='music' && form.mode!=='caption'" class="min-w-0">
     <label v-if="isClassic" class="display-body block text-zinc-300">Model
      <select v-model="form.engine" class="display-control mt-1 w-full max-w-md border border-white/10 bg-zinc-900 px-3 py-2 outline-none ring-amber-300/40 focus:ring-2">
       <option v-for="opt in engineOptions" :key="opt.value" :value="opt.value" :disabled="opt.disabled">{{ opt.label }}{{ opt.hint ? ' — '+opt.hint : '' }}</option>
@@ -68,7 +68,8 @@
      </button>
     </div>
    </div>
-   <p v-else class="display-body text-zinc-400">Model · YuE2</p>
+   <p v-else-if="form.mode==='music'" class="display-body text-zinc-400">Model · YuE2</p>
+   <p v-else class="display-body text-zinc-400">Model · Qwen2.5-VL caption</p>
   </div>
 
   <div class="grid min-w-0 gap-6 xl:grid-cols-[minmax(0,3fr)_minmax(24rem,2fr)] 2xl:gap-8">
@@ -103,6 +104,7 @@
      <button v-if="selected.kind!=='track'" class="rounded-full border border-white/20 px-4 py-2 text-sm outline-none ring-amber-300/40 focus-visible:ring-2" @click="restore(selected)">Use as input</button>
      <button v-if="selected.kind==='still'" class="rounded-full border border-white/20 px-4 py-2 text-sm outline-none ring-amber-300/40 focus-visible:ring-2" @click="Object.assign(form,useAsSource(form,selected))">Use as source still</button>
      <button v-if="selected.kind==='still'" class="rounded-full border border-white/20 px-4 py-2 text-sm outline-none ring-amber-300/40 focus-visible:ring-2" @click="Object.assign(form,useAsHero(form,selected))">Use as hero</button>
+     <button v-if="selected.kind==='still' || (selected.kind!=='track' && selected.kind!=='clip' && selected.id)" class="rounded-full border border-amber-300/40 px-4 py-2 text-sm text-amber-100 outline-none ring-amber-300/40 focus-visible:ring-2" :disabled="submitting" @click="describeSelected">Describe</button>
      <button v-if="selected.kind!=='track'" class="rounded-full border border-white/20 px-4 py-2 text-sm outline-none ring-amber-300/40 focus-visible:ring-2" @click="detailsOpen=true">Details</button>
      <button class="rounded-full border border-red-400/40 px-4 py-2 text-sm text-red-200 outline-none ring-amber-300/40 focus-visible:ring-2" @click="deleteOutput">Delete</button>
      <VideoUpscaleControl v-if="selected.kind==='clip'" :clip-id="selected.id" queue-only @complete="refresh" />
@@ -139,7 +141,7 @@
      </div>
     </div>
 
-    <section v-if="form.mode!=='music'" aria-label="Source" class="display-card">
+    <section v-if="form.mode!=='music' && form.mode!=='caption'" aria-label="Source" class="display-card">
      <div class="mb-3 flex flex-wrap items-start justify-between gap-3">
       <h2 class="text-xs uppercase tracking-wider text-zinc-400">Source</h2>
       <div v-if="isStudio" class="flex flex-wrap gap-4 text-sm text-zinc-300" aria-label="Identity locks">
@@ -194,6 +196,18 @@
       <input v-model="music.name" class="mt-1 w-full rounded-xl bg-zinc-900 p-3 outline-none ring-amber-300/40 focus:ring-2" placeholder="Optional track name">
      </label>
     </template>
+    <template v-else-if="form.mode==='caption'">
+     <p class="text-sm text-zinc-400">Qwen2.5-VL · image-to-text · exclusive GPU · unloads after one shot</p>
+     <div class="display-card space-y-3 p-3">
+      <Studio2AssetSlot label="Still to describe" :asset="captionStill" :hidden="slotHidden(captionStillId)" upload :disabled="uploading" @pick="picker='captionStillId'" @upload="uploadCaption($event)" />
+      <label class="block text-sm text-zinc-300">Caption style
+       <select v-model="captionStyle" class="mt-1 w-full rounded-xl border border-white/10 bg-zinc-900 p-3 outline-none ring-amber-300/40 focus:ring-2">
+        <option v-for="style in captionStyles" :key="style" :value="style">{{ style }}</option>
+       </select>
+      </label>
+      <p v-if="captionStyle==='delta'" class="text-xs text-zinc-500">Delta describes only changes from the locked look (bob / pink tank / blue shorts / Slytherin robe / barefoot).</p>
+     </div>
+    </template>
     <template v-else>
      <label class="block">Prompt<textarea v-model="form.promptSections.action" rows="4" class="mt-1 w-full rounded-xl bg-zinc-900 p-3 outline-none ring-amber-300/40 focus:ring-2" placeholder="Describe the image or the shot." /></label>
      <Studio2PromptControls v-if="video" v-model="form.promptSections" />
@@ -223,6 +237,25 @@
      <progress class="h-2 w-full accent-amber-300" max="100" :value="job.progress || 0" />
      <p class="text-xs text-zinc-400">{{ job.message }}</p>
     </div>
+    <div v-for="job in captionJobs" :key="job.id" class="space-y-2 rounded-xl border border-amber-300/25 bg-zinc-900 p-3 text-sm" aria-live="polite" role="status">
+     <div class="flex justify-between gap-3">
+      <div class="flex min-w-0 items-start gap-3">
+       <img v-if="job.request?.stillId || job.request?.imageAId" :src="stillUrl(job.request.stillId || job.request.imageAId)" class="h-14 w-14 shrink-0 rounded object-cover" alt="Caption source">
+       <div class="min-w-0">
+        <strong class="block truncate">Describe · {{ job.request?.captionStyle || 'caption' }}</strong>
+        <span class="capitalize text-amber-200">{{ job.state==='waiting'?'queued':job.state }}</span>
+       </div>
+      </div>
+      <button v-if="!['complete','failed','cancelled'].includes(job.state)" type="button" class="shrink-0 text-zinc-300" @click="cancel(job)">Cancel</button>
+     </div>
+     <p class="text-xs text-zinc-400">{{ elapsedCaption(job) }}</p>
+     <p v-if="job.resultText" class="whitespace-pre-wrap text-zinc-200">{{ job.resultText }}</p>
+     <div v-if="job.resultText" class="flex flex-wrap gap-2">
+      <button type="button" class="rounded-full border border-white/20 px-3 py-1.5 text-xs outline-none ring-amber-300/40 focus-visible:ring-2" @click="copyCaption(job.resultText)">Copy</button>
+      <button type="button" class="rounded-full border border-amber-300/40 px-3 py-1.5 text-xs text-amber-100 outline-none ring-amber-300/40 focus-visible:ring-2" @click="useCaptionAsPrompt(job.resultText)">Use as prompt</button>
+     </div>
+     <p v-if="job.error" role="alert" class="text-red-300">{{ job.error }}</p>
+    </div>
     <div v-for="job in musicJobs" :key="job.id" class="space-y-2 rounded-xl border border-amber-300/25 bg-zinc-900 p-3 text-sm" aria-live="polite" role="status">
      <div class="flex justify-between gap-3">
       <strong class="truncate">{{ job.name || 'YuE2' }}</strong>
@@ -233,7 +266,7 @@
      <p v-if="job.lastError || job.live?.error" role="alert" class="text-red-300">{{ job.lastError || job.live?.error }}</p>
     </div>
     <Studio2JobProgress v-for="job in benchJobs" :key="job.id" :job="job" :now="now" @select="focusJob(job)" @cancel="cancel(job)" />
-    <button v-if="folderJobs.some(j=>['complete','failed','cancelled'].includes(j.state)) || musicJobs.some(j=>['complete','done','error','cancelled'].includes(j.status))" type="button" class="text-sm text-zinc-400 outline-none ring-amber-300/40 focus-visible:ring-2" @click="clearFinished">Clear finished</button>
+    <button v-if="folderJobs.some(j=>['complete','failed','cancelled'].includes(j.state)) || musicJobs.some(j=>['complete','done','error','cancelled'].includes(j.status)) || captionJobs.some(j=>['complete','failed','cancelled'].includes(j.state))" type="button" class="text-sm text-zinc-400 outline-none ring-amber-300/40 focus-visible:ring-2" @click="clearFinished">Clear finished</button>
    </section>
   </div>
 
@@ -288,9 +321,10 @@
 import {createLoraMemory,loraUse} from '~/shared/studio2/lora-memory.mjs'
 import {filterLorasForStudio,filterLorasForUse} from '~/utils/loras'
 import {compilePrompt,sectionsFrom} from '~/shared/studio2/contracts.mjs'
+import {CAPTION_STYLES} from '~/shared/studio2/caption.mjs'
 import {aspectOptions,resolveSize,bindClip,changeSource,restoreAll,useAsHero,useAsSource} from '~/shared/studio2/input.mjs'
 import {folderAssets,newestOutput,assetLabel,reconcileSelection,previewHidden} from '~/shared/studio2/viewer.mjs'
-import {queueJobs} from '~/shared/studio2/queue-view.mjs'
+import {queueJobs,elapsedSeconds} from '~/shared/studio2/queue-view.mjs'
 import {gpuStatus} from '~/shared/studio2/status.mjs'
 import {applyUploadedStill} from '~/shared/studio2/upload.mjs'
 import {parseBatch,stylePrompt} from '~/shared/studio2/styles.mjs'
@@ -312,12 +346,15 @@ const liveMusic=ref<Record<string,any>>({})
 const form=reactive<any>({mode:'generate',engine:'flux',imageStyles:{positive:[],negative:[]},lockFace:true,lockOutfit:true,hideInput:xaigen,folderId:'',identityStillId:'',imageAId:'',imageBId:'',maskId:'',startClipId:'',endStillId:'',guides:[],promptSections:sectionsFrom({}),settings:{aspect:'auto',fps:24,steps:24,cfg:4,seed:null,seedMode:'random',duration:5,turbo:true,loraStack:[]}})
 const music=reactive({tags:DEFAULT_MUSIC_TAGS,lyrics:DEFAULT_MUSIC_LYRICS,duration:60,seed:'',name:''})
 const tagsPlaceholder=DEFAULT_MUSIC_TAGS,lyricsPlaceholder=DEFAULT_MUSIC_LYRICS
+const captionStyles=CAPTION_STYLES
+const captionStyle=ref('descriptive')
+const captionStillId=ref('')
 let loraMemory=createLoraMemory(xaigen)
 const currentLoraUse=computed(()=>loraUse(form))
 const pickerLoras=computed(()=>!xaigen && currentLoraUse.value==='ltx'?[]:filterLorasForUse(filterLorasForStudio([...loraNames.value.image,...loraNames.value.video],xaigen),currentLoraUse.value))
 watch(()=>[currentLoraUse.value,form.settings.loraStack],()=>loraMemory.sync(form),{deep:true,flush:'sync'})
 const route=useRoute()
-const tasks=['generate','edit','compose','refine','video','extend','music']
+const tasks=['generate','edit','compose','refine','video','extend','music','caption']
 const settingsOpen=ref(false),detailsOpen=ref(false),submitting=ref(false),error=ref(''),batchText=ref('')
 const video=computed(()=>['video','extend'].includes(form.mode))
 const kreaSticky=computed(()=>['edit','compose','iterate'].includes(form.mode))
@@ -353,11 +390,13 @@ const clips=computed(()=>library.value.clips.filter((s:any)=>s.folderId===form.f
 const compiled=computed(()=>compilePrompt(form.promptSections,video.value,form))
 const stillUrl=(id:string)=>`/api/library/stills/${id}`
 const folderJobs=computed(()=>jobs.value.filter(j=>j.request.folderId===form.folderId))
-const benchJobs=computed(()=>queueJobs(folderJobs.value))
+const captionJobs=computed(()=>folderJobs.value.filter(j=>j.request?.mode==='caption'))
+const benchJobs=computed(()=>queueJobs(folderJobs.value.filter(j=>j.request?.mode!=='caption')))
 const musicJobs=computed(()=>studioQueue.value
  .filter((j:any)=>j.kind==='music' && j.folderId===form.folderId && !['complete','done'].includes(j.status))
  .map((j:any)=>({...j,live:j.liveJobId?liveMusic.value[j.liveJobId]:null})))
-const gpu=computed(()=>gpuStatus(jobs.value,healthState.value,upscales.value,musicJobs.value))
+const gpu=computed(()=>gpuStatus(jobs.value,healthState.value,upscales.value,musicJobs.value,captionJobs.value))
+const captionStill=computed(()=>stills.value.find((s:any)=>s.id===captionStillId.value))
 const sourceSlot=computed(()=>{const clip=clips.value.find((a:any)=>a.id===form.startClipId);return form.mode==='extend'?(clip?{...clip,kind:'clip'}:null):inputStill.value})
 const pickerAssets=computed(()=>picker.value==='startClipId'?clips.value.map((a:any)=>({...a,kind:'clip'})):stills.value.map((a:any)=>({...a,kind:'still'})))
 const inputStill=computed(()=>stills.value.find((s:any)=>s.id===form.imageAId))
@@ -366,6 +405,42 @@ const sourceAsset=computed(()=>form.startClipId?clips.value.find((c:any)=>c.id==
 const sourceSize=computed(()=>measured[sourceAsset.value?.id] || sourceAsset.value)
 const resolvedSize=computed(()=>resolveSize(form.settings.aspect,sourceSize.value,undefined,form.engine))
 
+function elapsedCaption(job:any){
+ const seconds=elapsedSeconds(job,now.value)
+ return `${Math.floor(seconds/60)}m ${seconds%60}s ${job.startedAt||job.state==='rendering'||job.state==='saving'?'elapsed':'waiting'}`
+}
+async function copyCaption(text:string){
+ try{await navigator.clipboard.writeText(text)}catch{error.value='Could not copy caption.'}
+}
+function useCaptionAsPrompt(text:string){
+ const current=String(form.promptSections.action||'').trim()
+ form.promptSections.action=current?`${current}\n\n${text}`:text
+ if(form.mode==='caption' || form.mode==='music')form.mode='generate'
+}
+async function queueCaption(stillId:string){
+ if(!stillId){error.value='Choose a still to describe.';return false}
+ try{
+  await $fetch('/api/studio-2/caption',{method:'POST',body:{folderId:form.folderId,stillId,sourcePath:stillId,captionStyle:captionStyle.value}})
+  await refresh()
+  return true
+ }catch(e:any){error.value=e.data?.statusMessage||e.message;return false}
+}
+function describeSelected(){
+ const id=selected.value?.kind==='still'?selected.value.id:(selected.value?.kind==='clip'? '' : (selected.value?.id || form.imageAId || form.identityStillId))
+ if(!id){error.value='Select a still to describe.';return}
+ captionStillId.value=id
+ submitting.value=true;error.value=''
+ void queueCaption(id).finally(()=>{submitting.value=false})
+}
+async function uploadCaption(event:Event){
+ const input=event.target as HTMLInputElement,file=input.files?.[0];if(!file)return
+ uploading.value=true;uploadMessage.value='';error.value=''
+ const body=new FormData();body.append('image',file);body.append('folderId',form.folderId);body.append('hideInput',String(xaigen))
+ try{const response=await $fetch<any>('/api/studio-2/stills',{method:'POST',body});library.value=response;captionStillId.value=response.still.id;measured[response.still.id]={width:response.still.width,height:response.still.height};uploadMessage.value=`Loaded ${response.still.name || file.name} for caption.`}
+ catch(e:any){error.value=e.data?.statusMessage||e.message}
+ finally{uploading.value=false;input.value=''}
+}
+
 function isHidden(asset:any){
  if(!xaigen || !asset?.id)return false
  if(isClassic.value){
@@ -396,6 +471,11 @@ watch(()=>sourceAsset.value?.id,id=>{const asset=sourceAsset.value;if(!import.me
 
 function chooseTask(task:string){
  if(task==='music'){form.mode='music';return}
+ if(task==='caption'){
+  form.mode='caption'
+  captionStillId.value=selected.value?.kind==='still'?selected.value.id:form.imageAId||form.identityStillId||captionStillId.value
+  return
+ }
  if(task==='extend'){
   form.mode='extend'
   form.engine=xaigen && form.engine==='ltx'?'ltx':'minimax'
@@ -414,7 +494,7 @@ function selectOutput(item:any){selected.value=item;if(form.mode==='extend' && i
 function restore(item:any){Object.assign(form,restoreAll(form,item,xaigen,loraMemory));form.guides=form.guides||[];batchText.value=''}
 function focusJob(job:any){selectOutput(job.outputs?.at(-1)||null)}
 async function loadLoras(fresh=false){try{loraNames.value=await $fetch('/api/studio-2/loras'+(fresh?'?fresh=1':''))}catch{error.value='Could not refresh LoRAs. The last loaded list is still available.'}}
-function pickAsset(asset:any){const key=picker.value;if(key.startsWith('guide:'))form.guides[Number(key.split(':')[1])].stillId=asset?.id||'';else if(key==='startClipId')chooseClip(asset?.id||'');else form[key]=asset?.id||'';picker.value=''}
+function pickAsset(asset:any){const key=picker.value;if(key.startsWith('guide:'))form.guides[Number(key.split(':')[1])].stillId=asset?.id||'';else if(key==='startClipId')chooseClip(asset?.id||'');else if(key==='captionStillId')captionStillId.value=asset?.id||'';else form[key]=asset?.id||'';picker.value=''}
 async function clearFinished(){await $fetch('/api/studio-2/clear-finished',{method:'POST'});await refresh()}
 async function deleteOutput(){
  if(!selected.value)return
@@ -432,6 +512,10 @@ async function queue(){
    await refresh()
    return
   }
+  if(form.mode==='caption'){
+   await queueCaption(captionStillId.value || form.imageAId || form.identityStillId)
+   return
+  }
   if(form.settings.seedMode!=='locked')form.settings.seed=randomSeed()
   const queued=await $fetch<any>('/api/studio-2/jobs',{method:'POST',body:{...form,mode:form.mode==='edit' && parseBatch(batchText.value).length?'iterate':form.mode,hideInput:xaigen,hideOutput:false,promptSections:video.value?form.promptSections:{action:form.promptSections.action},settings:{...form.settings,...resolvedSize.value},batch:video.value || form.mode==='edit'?parseBatch(batchText.value):[]}})
   form.settings.seed=queued.seed;form.settings.width=queued.width;form.settings.height=queued.height
@@ -486,6 +570,7 @@ onMounted(async()=>{
  const asset=[...library.value.stills,...library.value.clips,...(library.value.tracks||[])].find((a:any)=>a.id===id)
  if(asset){selected.value={...asset,kind:route.query.clip?'clip':route.query.track?'track':'still'};if(route.query.use==='1'&&selected.value.kind!=='track')restore(selected.value);if(xaigen)toggleReveal(asset.id)}
  if(route.query.task==='music')form.mode='music'
+ if(route.query.task==='caption')form.mode='caption'
  const poll=async()=>{try{await refresh();const health=await $fetch<any>('/api/health');healthState.value=health}catch(e:any){healthState.value=null;error.value=e.data?.statusMessage||e.message}if(!disposed)timer=setTimeout(poll,3000)};void poll()
 })
 onBeforeUnmount(()=>{disposed=true;clearTimeout(timer);clearInterval(clock)})
diff --git a/docs/caption.md b/docs/caption.md
new file mode 100644
index 0000000..903eeeb
--- /dev/null
+++ b/docs/caption.md
@@ -0,0 +1,40 @@
+# Studio 2 image→text caption (Qwen2.5-VL NSFW Caption V4 GGUF)
+
+Caption jobs run on the Windows GPU host via **llama-server** (llama.cpp vision / mmproj). Not Comfy, not Klein, not JoyCaption.
+
+## Weights (~7GB — two files only)
+
+```powershell
+powershell -ExecutionPolicy Bypass -File scripts\setup-caption.ps1
+```
+
+Installs into the Shared models tree:
+
+`%LOCALAPPDATA%\Comfy-Desktop\ComfyUI-Shared\models\caption\qwen25vl-7b-nsfw-v4\`
+
+| File | Role |
+| --- | --- |
+| `Qwen2.5-VL-7B-NSFW-Caption-V4.Q5_K_M.gguf` | Language model |
+| `Qwen2.5-VL-7B-NSFW-Caption-V4.mmproj-f16.gguf` | Vision projector |
+
+Do **not** download the full 16.6GB safetensors repo.
+
+Runtime needs ~8–10GB VRAM. Exclusive GPU: host stops Comfy (and waits if YuE2/upscale is busy), loads the GGUF for one shot, then kills llama-server (`keep_alive 0`).
+
+## Host agent
+
+Requires `llama-server` on PATH (`winget install ggml.llamacpp`) or `CAPTION_LLAMA_SERVER`.
+
+Restart the Comfy host agent after setup. Confirm:
+
+```text
+GET http://127.0.0.1:8199/caption/status  →  { configured, busy, backend: "llama.cpp" }
+POST /caption  { imagePath, style }       →  load → { text } → unload
+POST /caption/jobs + PUT …/input          →  async job used by Studio 2
+```
+
+Styles: `descriptive` | `klein_prompt` | `delta` | `tags`.
+
+## App
+
+`POST /api/studio-2/caption` with `{ folderId, stillId|sourcePath, captionStyle }` queues a Studio job. Bench **Describe** button and the **caption** task pill both enqueue. Result stores `resultText` on the studio2 job and optionally writes `{still}.txt` beside the library file.
diff --git a/scripts/caption-host.mjs b/scripts/caption-host.mjs
new file mode 100644
index 0000000..48ba981
--- /dev/null
+++ b/scripts/caption-host.mjs
@@ -0,0 +1,331 @@
+import { spawn } from 'node:child_process'
+import { createServer } from 'node:net'
+import { existsSync, mkdirSync, readFileSync, writeFileSync, renameSync, appendFileSync, readdirSync, copyFileSync } from 'node:fs'
+import { join, resolve, extname } from 'node:path'
+import { captionStylePrompt, CAPTION_STYLES } from '../shared/studio2/caption.mjs'
+
+const MODEL_NAME = 'Qwen2.5-VL-7B-NSFW-Caption-V4.Q5_K_M.gguf'
+const MMPROJ_NAME = 'Qwen2.5-VL-7B-NSFW-Caption-V4.mmproj-f16.gguf'
+
+function defaultModelsDir() {
+  const shared = process.env.COMFY_MODELS_ROOT
+    || join(process.env.LOCALAPPDATA || '', 'Comfy-Desktop', 'ComfyUI-Shared', 'models')
+  return resolve(process.env.CAPTION_MODELS || join(shared, 'caption', 'qwen25vl-7b-nsfw-v4'))
+}
+
+function defaultLlamaServer() {
+  if (process.env.CAPTION_LLAMA_SERVER) return resolve(process.env.CAPTION_LLAMA_SERVER)
+  return 'llama-server'
+}
+
+function freePort() {
+  return new Promise((resolvePort, reject) => {
+    const server = createServer()
+    server.listen(0, '127.0.0.1', () => {
+      const address = server.address()
+      const port = typeof address === 'object' && address ? address.port : 0
+      server.close(error => error ? reject(error) : resolvePort(port))
+    })
+    server.on('error', reject)
+  })
+}
+
+async function waitForServer(port, signal, timeoutMs = 120_000, fetchImpl = fetch) {
+  const started = Date.now()
+  while (Date.now() - started < timeoutMs) {
+    if (signal?.aborted) throw new Error('Caption cancelled while loading the model.')
+    try {
+      const response = await fetchImpl(`http://127.0.0.1:${port}/health`, { signal: AbortSignal.timeout(2000) })
+      if (response.ok) return
+    } catch { /* still booting */ }
+    await new Promise(r => setTimeout(r, 500))
+  }
+  throw new Error('llama-server did not become ready in time.')
+}
+
+function mimeFor(path) {
+  const ext = extname(path).toLowerCase()
+  if (ext === '.jpg' || ext === '.jpeg') return 'image/jpeg'
+  if (ext === '.webp') return 'image/webp'
+  if (ext === '.gif') return 'image/gif'
+  return 'image/png'
+}
+
+function killTree(child) {
+  return new Promise(resolveKill => {
+    if (!child?.pid) return resolveKill()
+    let finished = false
+    const done = () => {
+      if (finished) return
+      finished = true
+      resolveKill()
+    }
+    child.once('close', done)
+    try {
+      if (typeof child.kill === 'function') child.kill()
+    } catch { /* ignore */ }
+    if (process.platform === 'win32' && child.pid > 0) {
+      try {
+        const killer = spawn('taskkill', ['/PID', String(child.pid), '/T', '/F'], { windowsHide: true, stdio: 'ignore' })
+        killer.once('close', done)
+        killer.once('error', done)
+      } catch {
+        done()
+      }
+    }
+    setTimeout(done, 3000)
+  })
+}
+
+export function validateCaptionHostRequest(body) {
+  if (!/^[a-zA-Z0-9-]{12,80}$/.test(body?.id || '')) throw new Error('Invalid caption job ID.')
+  const style = String(body.style || body.captionStyle || 'descriptive')
+  if (!CAPTION_STYLES.includes(style)) throw new Error('Unknown caption style.')
+  return { id: body.id, style, imagePath: body.imagePath ? String(body.imagePath) : '' }
+}
+
+/** One llama-server process per caption. Process exit is the VRAM unload boundary (keep_alive 0). */
+export function createCaptionHost({
+  prepare,
+  leaseValid,
+  spawnProcess = spawn,
+  modelsDir,
+  llamaServer,
+  dataDir,
+  fetchImpl = fetch
+} = {}) {
+  const models = resolve(modelsDir || defaultModelsDir())
+  const executable = llamaServer || defaultLlamaServer()
+  const data = resolve(dataDir || process.env.CAPTION_JOBS_DIR || join(models, 'aigen-jobs'))
+  let active = null
+  let holdUntil = 0
+  if (existsSync(data)) {
+    for (const id of readdirSync(data)) {
+      try {
+        const path = join(data, id, 'status.json')
+        if (!existsSync(path)) continue
+        const state = JSON.parse(readFileSync(path, 'utf8'))
+        if (['running', 'starting', 'cancelling'].includes(state.status)) {
+          holdUntil = Date.now() + 10000
+          state.status = 'error'
+          state.error = 'Caption host restarted. GPU model unloaded.'
+          writeFileSync(path + '.tmp', JSON.stringify(state))
+          renameSync(path + '.tmp', path)
+        }
+      } catch { /* ignore bad records */ }
+    }
+  }
+  const dir = id => {
+    if (!/^[a-zA-Z0-9-]{12,80}$/.test(id || '')) throw new Error('Invalid caption job ID.')
+    return join(data, id)
+  }
+  const persist = job => {
+    const target = join(dir(job.id), 'status.json')
+    writeFileSync(target + '.tmp', JSON.stringify(job))
+    renameSync(target + '.tmp', target)
+  }
+  const read = id => {
+    if (active?.job.id === id) return { ...active.job, text: active.job.text }
+    const path = join(dir(id), 'status.json')
+    if (!existsSync(path)) return null
+    return JSON.parse(readFileSync(path, 'utf8'))
+  }
+  const modelPath = () => join(models, MODEL_NAME)
+  const mmprojPath = () => join(models, MMPROJ_NAME)
+  const configured = () => {
+    try {
+      if (!existsSync(modelPath()) || !existsSync(mmprojPath())) return false
+      if (executable.includes('\\') || executable.includes('/')) return existsSync(executable)
+      return true
+    } catch { return false }
+  }
+
+  return {
+    busy: () => Boolean(active) || Date.now() < holdUntil,
+    configured,
+    modelsDir: () => models,
+    read,
+    async upload(id, stream) {
+      if (read(id)?.status === 'complete') throw new Error('This caption job has already finished.')
+      const jobDir = dir(id)
+      mkdirSync(jobDir, { recursive: true })
+      const dest = join(jobDir, 'input.upload')
+      const { createWriteStream } = await import('node:fs')
+      const { pipeline } = await import('node:stream/promises')
+      const { Transform } = await import('node:stream')
+      let bytes = 0
+      await pipeline(stream, new Transform({
+        transform(chunk, _, callback) {
+          bytes += chunk.length
+          callback(bytes > 40 * 1024 * 1024 ? new Error('Image exceeds the 40 MB upload limit.') : null, chunk)
+        }
+      }), createWriteStream(dest, { flags: 'w' }))
+      if (bytes < 32) throw new Error('Image file is empty.')
+      renameSync(dest, join(jobDir, 'input.png'))
+    },
+    async start(body, lease) {
+      const request = validateCaptionHostRequest(body)
+      const previous = read(request.id)
+      if (previous) return previous
+      if (active || Date.now() < holdUntil) throw Object.assign(new Error('Caption is already running or releasing VRAM.'), { statusCode: 409 })
+      if (!configured()) throw new Error(`Caption model is not installed. Expected ${MODEL_NAME} and ${MMPROJ_NAME} under ${models}. Run scripts/setup-caption.ps1.`)
+      if (!leaseValid(lease)) throw new Error('GPU reservation expired.')
+
+      let imagePath = request.imagePath
+      if (imagePath) {
+        if (!existsSync(imagePath)) throw new Error('imagePath does not exist on the GPU host.')
+        mkdirSync(dir(request.id), { recursive: true })
+        const dest = join(dir(request.id), `input${extname(imagePath) || '.png'}`)
+        copyFileSync(imagePath, dest)
+        imagePath = dest
+      } else {
+        imagePath = join(dir(request.id), 'input.png')
+        if (!existsSync(imagePath)) {
+          const alt = readdirSync(dir(request.id)).find(name => /^input\./i.test(name))
+          if (!alt) throw new Error('Upload an image first or pass imagePath.')
+          imagePath = join(dir(request.id), alt)
+        }
+      }
+
+      const job = {
+        id: request.id,
+        status: 'starting',
+        message: 'Preparing GPU for caption',
+        progress: 0,
+        style: request.style,
+        startedAt: Date.now(),
+        checkedAt: Date.now()
+      }
+      active = { job, child: null, cancelled: false, abort: new AbortController() }
+      const run = active
+      mkdirSync(dir(job.id), { recursive: true })
+      writeFileSync(join(dir(job.id), 'request.json'), JSON.stringify({ ...request, imagePath, prompt: captionStylePrompt(request.style) }))
+      persist(job)
+
+      try {
+        if (prepare) await prepare()
+        if (run.cancelled || !leaseValid(lease)) throw new Error('Caption start cancelled or GPU reservation expired.')
+
+        job.status = 'running'
+        job.message = 'Loading Qwen2.5-VL caption model'
+        job.progress = 5
+        persist(job)
+
+        const port = await freePort()
+        const args = [
+          '-m', modelPath(),
+          '--mmproj', mmprojPath(),
+          '--host', '127.0.0.1',
+          '--port', String(port),
+          '-ngl', String(process.env.CAPTION_NGL || '99'),
+          '-c', String(process.env.CAPTION_CTX || '4096'),
+          '--jinja'
+        ]
+        const child = spawnProcess(executable, args, {
+          windowsHide: true,
+          shell: false,
+          stdio: ['ignore', 'pipe', 'pipe'],
+          env: { ...process.env }
+        })
+        run.child = child
+        const log = chunk => appendFileSync(join(dir(job.id), 'worker.log'), chunk)
+        child.stdout.on('data', log)
+        child.stderr.on('data', log)
+
+        const watchdog = setInterval(() => {
+          if (!leaseValid(lease)) {
+            job.error = 'GPU reservation expired; caption stopped.'
+            run.abort.abort()
+            void killTree(child)
+          }
+        }, 5000)
+
+        try {
+          await waitForServer(port, run.abort.signal, 120_000, fetchImpl)
+          if (run.cancelled) throw new Error('Cancelled')
+          job.message = 'Captioning'
+          job.progress = 40
+          persist(job)
+
+          const bytes = readFileSync(imagePath)
+          const dataUrl = `data:${mimeFor(imagePath)};base64,${bytes.toString('base64')}`
+          const timeout = AbortSignal.timeout(Number(process.env.CAPTION_TIMEOUT_MS || 180_000))
+          const onAbort = () => { /* combined via race below */ }
+          run.abort.signal.addEventListener('abort', onAbort, { once: true })
+          let response
+          try {
+            response = await fetchImpl(`http://127.0.0.1:${port}/v1/chat/completions`, {
+              method: 'POST',
+              headers: { 'Content-Type': 'application/json' },
+              signal: run.abort.signal.aborted ? run.abort.signal : timeout,
+              body: JSON.stringify({
+                temperature: 0.2,
+                max_tokens: 512,
+                messages: [{
+                  role: 'user',
+                  content: [
+                    { type: 'text', text: captionStylePrompt(request.style) },
+                    { type: 'image_url', image_url: { url: dataUrl } }
+                  ]
+                }]
+              })
+            })
+          } finally {
+            run.abort.signal.removeEventListener('abort', onAbort)
+          }
+          if (run.abort.signal.aborted) throw new Error('Cancelled')
+          if (!response.ok) {
+            const detail = await response.text().catch(() => '')
+            throw new Error(`llama-server caption failed (${response.status}): ${detail.slice(0, 400)}`)
+          }
+          const payload = await response.json()
+          const text = String(payload?.choices?.[0]?.message?.content || '').trim()
+          if (!text) throw new Error('Caption model returned empty text.')
+          job.text = text
+          job.status = run.cancelled ? 'cancelled' : 'complete'
+          job.message = job.status === 'complete' ? 'Caption ready' : 'Cancelled'
+          job.progress = 100
+          job.checkedAt = Date.now()
+          persist(job)
+          return { ...job }
+        } finally {
+          clearInterval(watchdog)
+          await killTree(child)
+          // keep_alive 0: process exit unloads GGUF+mmproj from VRAM
+          holdUntil = Date.now() + 2000
+          if (active === run) active = null
+        }
+      } catch (error) {
+        job.status = run.cancelled ? 'cancelled' : 'error'
+        job.error = error.message || String(error)
+        job.message = job.error
+        job.checkedAt = Date.now()
+        persist(job)
+        if (run.child) await killTree(run.child)
+        if (active === run) active = null
+        holdUntil = Date.now() + 2000
+        throw error
+      }
+    },
+    async cancel(id) {
+      if (active?.job.id !== id) return read(id)
+      const run = active
+      run.cancelled = true
+      run.job.status = 'cancelling'
+      run.job.message = 'Cancelling'
+      persist(run.job)
+      run.abort.abort()
+      if (run.child) await killTree(run.child)
+      return read(id)
+    },
+    /** Sync one-shot used by POST /caption { imagePath, style }. */
+    async captionOnce(body, lease) {
+      const id = body.id || `caption-${Date.now()}-${Math.random().toString(36).slice(2, 10)}`
+      const result = await this.start({ ...body, id }, lease)
+      if (result.status === 'complete') return { text: result.text, id: result.id, style: result.style }
+      throw new Error(result.error || 'Caption failed.')
+    }
+  }
+}
+
+export const captionModelFiles = { model: MODEL_NAME, mmproj: MMPROJ_NAME }
diff --git a/scripts/comfy-host-agent.mjs b/scripts/comfy-host-agent.mjs
index 5258981..200f749 100644
--- a/scripts/comfy-host-agent.mjs
+++ b/scripts/comfy-host-agent.mjs
@@ -4,6 +4,7 @@ import { stableMemoryArgs } from './comfy-memory-policy.mjs'
 import { createGpuReservation } from './gpu-reservation.mjs'
 import { createGpuProxy } from './gpu-proxy.mjs'
 import { createYue2Host } from './yue2-host.mjs'
+import { createCaptionHost } from './caption-host.mjs'
 import http from 'node:http'
 import net from 'node:net'
 import { execFile, spawn } from 'node:child_process'
@@ -147,7 +148,7 @@ let proxyTarget = 0
 
 function ensureProxyListening() {
   if (proxyServer) return
-  proxyServer = createGpuProxy({ target: () => proxyTarget, reservation: gpuReservation, authorized, markWork, externalBusy: () => yue2.busy() || upscale.busy() })
+  proxyServer = createGpuProxy({ target: () => proxyTarget, reservation: gpuReservation, authorized, markWork, externalBusy: () => yue2.busy() || upscale.busy() || caption.busy() })
   proxyServer.on('error', (error) => {
     console.log(JSON.stringify({ src: 'comfy-host-agent', event: 'proxy-error', error: String(error.message || error) }))
   })
@@ -819,7 +820,7 @@ function purgeDesktopFiles(body) {
 }
 
 const gpuReservation = createGpuReservation({ idle: async () => {
-  if (yue2.busy() || upscale.busy()) return false
+  if (yue2.busy() || upscale.busy() || caption.busy()) return false
   if ((await trainingLock()).busy) return false
   const healthy = await syncProxy()
   if (healthy) {
@@ -830,29 +831,67 @@ const gpuReservation = createGpuReservation({ idle: async () => {
   return !(await processUp()) && !(await pythonMainUp().catch(() => true))
 } })
 
-const yue2 = createYue2Host({
-  leaseValid: lease => gpuReservation.isOwner(lease),
-  prepare: async () => {
-    if ((await trainingLock()).busy) throw new Error('GPU is busy with training.')
-    const healthy = await syncProxy()
-    if (healthy) {
-      const queue = await fetchLocalQueue(healthy)
-      if (!queue.ok || queue.running || queue.pending) throw new Error('Comfy is busy; YuE2 cannot start.')
-    }
-    // Stop Comfy and refuse to launch while its Python still owns VRAM.
-    if (healthy || await processUp() || await pythonMainUp().catch(() => false)) {
-      await stopComfyProcesses()
-      markAsleep()
-    }
-    if (await pythonMainUp()) throw new Error('Comfy has not stopped; retry after the GPU is free.')
+async function prepareExclusiveGpu(label) {
+  if ((await trainingLock()).busy) throw new Error('GPU is busy with training.')
+  if (label !== 'YuE2' && yue2.busy()) throw new Error('YuE2 is using the GPU.')
+  if (label !== 'caption' && caption.busy()) throw new Error('Caption is using the GPU.')
+  if (upscale.busy()) throw new Error('Local upscale is using the GPU.')
+  const healthy = await syncProxy()
+  if (healthy) {
+    const queue = await fetchLocalQueue(healthy)
+    if (!queue.ok || queue.running || queue.pending) throw new Error(`Comfy is busy; ${label} cannot start.`)
   }
-})
+  // Stop Comfy and refuse to launch while its Python still owns VRAM.
+  if (healthy || await processUp() || await pythonMainUp().catch(() => false)) {
+    await stopComfyProcesses()
+    markAsleep()
+  }
+  if (await pythonMainUp()) throw new Error('Comfy has not stopped; retry after the GPU is free.')
+}
 
 const upscale = createUpscaleHost({ leaseValid: token => gpuReservation.isOwner(token) })
 
+const yue2 = createYue2Host({
+  leaseValid: lease => gpuReservation.isOwner(lease),
+  prepare: async () => prepareExclusiveGpu('YuE2')
+})
+
+const caption = createCaptionHost({
+  leaseValid: lease => gpuReservation.isOwner(lease),
+  prepare: async () => prepareExclusiveGpu('caption')
+})
+
 async function handleControl(req, res) {
   if (!authorized(req)) return json(res, 401, { ok: false, error: 'unauthorized' })
   const url = new URL(req.url || '/', 'http://localhost')
+  if (url.pathname.startsWith('/caption')) {
+    const match = url.pathname.match(/^\/caption\/jobs\/([a-zA-Z0-9-]{12,80})(\/input|\/cancel)?$/)
+    if (req.method === 'GET' && url.pathname === '/caption/status') {
+      return json(res, 200, { configured: caption.configured(), busy: caption.busy(), backend: 'llama.cpp', modelsDir: caption.modelsDir() })
+    }
+    // Sync one-shot: POST /caption { imagePath, style } → load → caption → unload → { text }
+    if (req.method === 'POST' && url.pathname === '/caption') {
+      try {
+        const body = await readJson(req)
+        return json(res, 200, await caption.captionOnce(body, String(req.headers['x-aigen-gpu-lease'] || '')))
+      } catch (error) {
+        return json(res, error.statusCode || 400, { error: error.message || 'Caption failed' })
+      }
+    }
+    if (req.method === 'POST' && url.pathname === '/caption/jobs') {
+      return json(res, 200, await caption.start(await readJson(req), String(req.headers['x-aigen-gpu-lease'] || '')))
+    }
+    if (match && req.method === 'PUT' && match[2] === '/input') {
+      await caption.upload(match[1], req)
+      return json(res, 200, { uploaded: true })
+    }
+    if (match && req.method === 'POST' && match[2] === '/cancel') return json(res, 200, await caption.cancel(match[1]))
+    if (match && req.method === 'GET' && !match[2]) {
+      const job = caption.read(match[1])
+      return json(res, job ? 200 : 404, job || { error: 'Caption job not found' })
+    }
+    return json(res, 404, { error: 'Unknown caption endpoint' })
+  }
   if (url.pathname.startsWith('/upscale/')) {
     const match = url.pathname.match(/^\/upscale\/jobs\/([a-zA-Z0-9-]{12,80})(\/input|\/video|\/cancel)?$/)
     if (req.method === 'POST' && url.pathname === '/upscale/jobs') return json(res, 200, upscale.start(await readJson(req), String(req.headers['x-aigen-gpu-lease'] || '')))
@@ -909,12 +948,14 @@ async function handleControl(req, res) {
       gpu: gpuReservation.availability(),
       training: { busy: lastTraining.busy },
       yue2: { busy: yue2.busy(), configured: yue2.configured() },
+      caption: { busy: caption.busy(), configured: caption.configured() },
       upscale: { busy: upscale.busy(), engine: 'realesrgan-rife', local: true }
     })
   }
   if (req.method === 'POST' && url.pathname === '/start') {
     if (upscale.busy()) return json(res, 409, { message: 'Local upscale is using the GPU.' })
     if (yue2.busy()) return json(res, 409, { message: 'YuE2 is using the GPU.' })
+    if (caption.busy()) return json(res, 409, { message: 'Caption is using the GPU.' })
     const training = await trainingLock()
     if (training.busy) {
       return json(res, 409, {
@@ -1016,7 +1057,7 @@ const server = http.createServer(async (req, res) => {
     } else await handleControl(req, res)
   } catch (error) {
     req.resume()
-    if ((String(req.url || '').startsWith('/yue2/') || String(req.url || '').startsWith('/upscale/')) && !res.headersSent) return json(res, error.statusCode || 400, { error: error.message || 'Music host request failed' })
+    if ((String(req.url || '').startsWith('/yue2/') || String(req.url || '').startsWith('/upscale/') || String(req.url || '').startsWith('/caption')) && !res.headersSent) return json(res, error.statusCode || 400, { error: error.message || 'Host request failed' })
     if (!res.headersSent) json(res, error.statusCode || 400, { ok: false, message: error.statusCode === 409 ? 'GPU is in use. Waiting for availability.' : 'GPU coordination request failed.' })
   }
 })
diff --git a/scripts/setup-caption.ps1 b/scripts/setup-caption.ps1
new file mode 100644
index 0000000..4c19cb4
--- /dev/null
+++ b/scripts/setup-caption.ps1
@@ -0,0 +1,129 @@
+# Download Qwen2.5-VL NSFW Caption V4 GGUF (Q5_K_M + mmproj only) for Studio 2 caption jobs.
+# Does NOT pull the full safetensors repo (~16.6GB).
+#
+# Example:
+#   powershell -ExecutionPolicy Bypass -File scripts\setup-caption.ps1
+#   powershell -File scripts\setup-caption.ps1 -SkipDownload
+
+[CmdletBinding()]
+param(
+  [string]$ModelsRoot = '',
+  [string]$LlamaServer = '',
+  [switch]$SkipDownload,
+  [switch]$Force
+)
+
+$ErrorActionPreference = 'Stop'
+$ProgressPreference = 'Continue'
+
+function Write-Step([string]$Message) {
+  Write-Host ""
+  Write-Host "==> $Message" -ForegroundColor Cyan
+}
+
+function Write-Ok([string]$Message) {
+  Write-Host "    $Message" -ForegroundColor Green
+}
+
+function Write-Warn([string]$Message) {
+  Write-Host "    warn  $Message" -ForegroundColor Yellow
+}
+
+function Resolve-ModelsRoot([string]$Hint) {
+  $shared = Join-Path $env:LOCALAPPDATA 'Comfy-Desktop\ComfyUI-Shared\models'
+  $candidates = @(
+    $Hint,
+    $env:COMFY_MODELS_ROOT,
+    $shared
+  ) | Where-Object { $_ } | ForEach-Object { $_.TrimEnd('\', '/') }
+
+  foreach ($path in $candidates) {
+    if (Test-Path $path) { return (Resolve-Path $path).Path }
+  }
+  New-Item -ItemType Directory -Force -Path $shared | Out-Null
+  return (Resolve-Path $shared).Path
+}
+
+function Find-HfCli {
+  foreach ($name in @('hf', 'huggingface-cli')) {
+    $cmd = Get-Command $name -ErrorAction SilentlyContinue
+    if ($cmd) { return @{ Name = $name; Source = $cmd.Source } }
+  }
+  throw "Hugging Face CLI not found (hf / huggingface-cli). Install with: pip install -U huggingface_hub"
+}
+
+function Ensure-Dir([string]$Path) {
+  if (-not (Test-Path $Path)) {
+    New-Item -ItemType Directory -Force -Path $Path | Out-Null
+  }
+}
+
+Write-Step 'Resolve models root'
+$modelsRoot = Resolve-ModelsRoot $ModelsRoot
+$captionDir = Join-Path $modelsRoot 'caption\qwen25vl-7b-nsfw-v4'
+Ensure-Dir $captionDir
+Write-Ok "Models root: $modelsRoot"
+Write-Ok "Caption dir: $captionDir"
+
+$model = 'Qwen2.5-VL-7B-NSFW-Caption-V4.Q5_K_M.gguf'
+$mmproj = 'Qwen2.5-VL-7B-NSFW-Caption-V4.mmproj-f16.gguf'
+$modelPath = Join-Path $captionDir $model
+$mmprojPath = Join-Path $captionDir $mmproj
+
+if (-not $SkipDownload) {
+  Write-Step 'Download GGUF + mmproj only (~7GB)'
+  $needModel = $Force -or -not (Test-Path $modelPath)
+  $needMmproj = $Force -or -not (Test-Path $mmprojPath)
+  if (-not $needModel -and -not $needMmproj) {
+    Write-Ok 'Both weight files already present.'
+  } else {
+    $hf = Find-HfCli
+    if ($hf.Name -eq 'hf') {
+      & $hf.Source download mradermacher/Qwen2.5-VL-7B-NSFW-Caption-V4-GGUF `
+        --include $model `
+        --include $mmproj `
+        --local-dir $captionDir
+    } else {
+      & $hf.Source download mradermacher/Qwen2.5-VL-7B-NSFW-Caption-V4-GGUF `
+        --include $model `
+        --include $mmproj `
+        --local-dir $captionDir
+    }
+    if (-not (Test-Path $modelPath)) { throw "Missing $model after download." }
+    if (-not (Test-Path $mmprojPath)) { throw "Missing $mmproj after download." }
+    Write-Ok 'Download complete.'
+  }
+} else {
+  Write-Warn 'SkipDownload set — not fetching weights.'
+}
+
+Write-Step 'Locate llama-server'
+$server = $LlamaServer
+if (-not $server) { $server = $env:CAPTION_LLAMA_SERVER }
+if (-not $server) {
+  $cmd = Get-Command llama-server -ErrorAction SilentlyContinue
+  if ($cmd) { $server = $cmd.Source }
+}
+if ($server) {
+  Write-Ok "llama-server: $server"
+} else {
+  Write-Warn 'llama-server not on PATH. Install with: winget install ggml.llamacpp'
+  Write-Warn 'Or set CAPTION_LLAMA_SERVER to a CUDA build of llama-server.exe'
+}
+
+$ready = @{
+  model = $modelPath
+  mmproj = $mmprojPath
+  modelsDir = $captionDir
+  llamaServer = $server
+  backend = 'llama.cpp'
+  updatedAt = (Get-Date).ToString('o')
+}
+$readyPath = Join-Path $captionDir 'aigen-ready.json'
+$ready | ConvertTo-Json | Set-Content -Path $readyPath -Encoding utf8
+Write-Ok "Wrote $readyPath"
+Write-Host ""
+Write-Host "Caption host looks for:" -ForegroundColor Cyan
+Write-Host "  $modelPath"
+Write-Host "  $mmprojPath"
+Write-Host "Restart the Comfy host agent after install so /caption/status reports configured=true."
diff --git a/server/api/health.get.ts b/server/api/health.get.ts
index f82db21..d177cca 100644
--- a/server/api/health.get.ts
+++ b/server/api/health.get.ts
@@ -48,7 +48,7 @@ export default defineEventHandler(async () => {
       host: comfy.host || '',
       queueRunning: queue.running,
       queuePending: queue.pending,
-      asleep: Boolean(control?.asleep) && !comfyReachable && !control?.yue2?.busy,
+      asleep: Boolean(control?.asleep) && !comfyReachable && !control?.yue2?.busy && !control?.caption?.busy,
       processUp: Boolean(control?.process ?? control?.processUp),
       lastActivityAt: control?.lastActivityAt || null,
       stats: comfy.ok ? comfy.stats : undefined
@@ -58,6 +58,11 @@ export default defineEventHandler(async () => {
       busy: Boolean(control?.yue2?.busy),
       backend: control?.yue2?.backend || 'yue2'
     },
+    caption: {
+      configured: Boolean(control?.caption?.configured),
+      busy: Boolean(control?.caption?.busy),
+      backend: control?.caption?.backend || 'llama.cpp'
+    },
     imageComfy: {
       configured: imageConfigured,
       ok: imageOk,
diff --git a/server/api/studio-2/caption.post.ts b/server/api/studio-2/caption.post.ts
new file mode 100644
index 0000000..7b0059e
--- /dev/null
+++ b/server/api/studio-2/caption.post.ts
@@ -0,0 +1,74 @@
+import { validateCaptionRequest } from '~/shared/studio2/caption.mjs'
+import { saveRecord, readRecord } from '../../utils/studio2/store'
+import { addStudioJob, kickStudioQueue, type StudioJobPayload } from '../../utils/studioQueue'
+import { getStill } from '../../utils/library'
+
+export default defineEventHandler(async (event) => {
+  const { owner } = assertLibraryOwner(event)
+  const raw = await readBody(event)
+  let request: ReturnType<typeof validateCaptionRequest>
+  try {
+    request = validateCaptionRequest(raw)
+  } catch (e: any) {
+    throw createError({ statusCode: e.statusCode || 400, statusMessage: e.message })
+  }
+  assertFolderAccess(event, request.folderId)
+  let stillId = request.stillId
+  if (!stillId && request.sourcePath) {
+    // sourcePath may be a still id when the client already resolved a library asset.
+    stillId = String(request.sourcePath)
+  }
+  const still = getStill(owner, stillId)
+  assertFolderAccess(event, still.folderId)
+  request.stillId = still.id
+  request.imageAId = still.id
+  request.sourcePath = still.id
+
+  const id = crypto.randomUUID()
+  const record = {
+    id,
+    owner,
+    request,
+    state: 'waiting',
+    queuedAt: Date.now(),
+    familyId: crypto.randomUUID(),
+    outputs: [],
+    resultText: '',
+    purgeResult: 'Not yet saved'
+  }
+  saveRecord(record)
+  const row = await addStudioJob({
+    ownerKey: owner,
+    kind: 'caption',
+    familyId: record.familyId,
+    payload: {
+      studio2Id: id,
+      prompt: request.compiledPrompt,
+      name: `Describe · ${request.captionStyle}`,
+      folderId: request.folderId,
+      stillId: still.id,
+      captionStyle: request.captionStyle,
+      aspect: 'auto',
+      width: 0,
+      height: 0,
+      steps: 1,
+      turbo: true,
+      seed: 0,
+      cfg: 0,
+      fps: 24,
+      samplerName: 'euler',
+      scheduler: 'simple',
+      duration: 0,
+      sound: false,
+      workflow: 'minimax',
+      useIdentityRefs: false,
+      hideThumbnail: false,
+      referenceStillIds: [],
+      extensions: [],
+      queueAutoRun: true
+    } as StudioJobPayload
+  })
+  saveRecord({ ...readRecord(owner, id), queueId: row.id })
+  kickStudioQueue()
+  return { id, captionStyle: request.captionStyle, stillId: still.id }
+})
diff --git a/server/plugins/00-resume-caption.ts b/server/plugins/00-resume-caption.ts
new file mode 100644
index 0000000..fa70bfd
--- /dev/null
+++ b/server/plugins/00-resume-caption.ts
@@ -0,0 +1,3 @@
+import { resumeCaptionJobs } from '~/server/utils/caption'
+
+export default defineNitroPlugin(() => { resumeCaptionJobs() })
diff --git a/server/utils/caption.ts b/server/utils/caption.ts
new file mode 100644
index 0000000..fc41757
--- /dev/null
+++ b/server/utils/caption.ts
@@ -0,0 +1,268 @@
+import { createReadStream, existsSync, mkdirSync, readdirSync, readFileSync, writeFileSync, renameSync, unlinkSync } from 'node:fs'
+import { join } from 'node:path'
+import { createJob, emitJob, getJob, restoreJob, type Job } from './jobs'
+import { getStill, stillPath } from './library'
+import { sharedGpuHeaders } from './sharedGpu'
+import { CAPTION_STYLES } from '~/shared/studio2/caption.mjs'
+
+function settings() {
+  const config = useRuntimeConfig()
+  return {
+    url: String(config.comfyControlUrl || process.env.COMFY_CONTROL_URL || '').replace(/\/$/, ''),
+    token: String(config.comfyControlToken || process.env.COMFY_CONTROL_TOKEN || '')
+  }
+}
+
+export function captionConfigured() { return Boolean(settings().url) }
+
+function pendingRoot() {
+  return join(String(useRuntimeConfig().libraryDir || process.env.LIBRARY_DIR || '/data/library'), 'caption-pending')
+}
+
+export function captionPendingAlive(jobId: string) {
+  if (!jobId) return false
+  return existsSync(join(pendingRoot(), `${jobId}.json`))
+}
+
+async function request(path: string, method = 'GET', body?: unknown) {
+  const { url, token } = settings()
+  if (!url) throw new Error('Caption host is not configured. Set COMFY_CONTROL_URL.')
+  const response = await fetch(`${url}/caption/${path}`, {
+    method,
+    headers: {
+      ...(token ? { Authorization: `Bearer ${token}` } : {}),
+      ...(method === 'GET' ? {} : sharedGpuHeaders()),
+      ...(method === 'POST' ? { 'Content-Type': 'application/json' } : {})
+    },
+    body: method === 'POST' ? JSON.stringify(body) : body as BodyInit | undefined,
+    ...(method === 'PUT' ? { duplex: 'half' as const } : {}),
+    signal: AbortSignal.timeout(method === 'PUT' ? 120_000 : 60_000)
+  } as RequestInit)
+  if (!response.ok) {
+    const detail = await response.json().catch(() => ({})) as { message?: string; error?: string }
+    throw Object.assign(new Error(detail.message || detail.error || `Caption host returned ${response.status}`), { statusCode: response.status })
+  }
+  return response
+}
+
+function persist(record: Record<string, unknown>) {
+  mkdirSync(pendingRoot(), { recursive: true })
+  const path = join(pendingRoot(), `${record.id}.json`)
+  writeFileSync(path + '.tmp', JSON.stringify(record))
+  renameSync(path + '.tmp', path)
+}
+
+function clearPending(id: string) {
+  const path = join(pendingRoot(), `${id}.json`)
+  if (existsSync(path)) unlinkSync(path)
+}
+
+function writeSidecar(owner: string, stillId: string, text: string) {
+  try {
+    const image = stillPath(owner, stillId)
+    if (!existsSync(image)) return
+    writeFileSync(`${image}.txt`, text, 'utf8')
+  } catch { /* optional sidecar */ }
+}
+
+export async function cancelCaptionJob(job: Job) {
+  await request(`jobs/${job.id}/cancel`, 'POST', {})
+  job.status = 'cancelled'
+  emitJob(job, { type: 'error', error: 'Cancelled', message: 'Cancelled' })
+}
+
+async function settle(job: Job) {
+  const { onLiveVideoSettled } = await import('./studioQueue')
+  await onLiveVideoSettled(job)
+  clearPending(job.id)
+}
+
+async function watch(job: Job, record: {
+  id: string
+  owner: string
+  stillId: string
+  folderId: string
+  captionStyle: string
+  studio2Id?: string
+  liveId: string
+}) {
+  let failures = 0
+  while (job.status !== 'cancelled') {
+    try {
+      const state = await (await request(`jobs/${job.id}`)).json() as {
+        status: string
+        message?: string
+        error?: string
+        progress?: number
+        text?: string
+      }
+      if (job.status === 'cancelled') { await settle(job); return }
+      if (state.status === 'error' || state.status === 'cancelled') {
+        job.status = state.status === 'cancelled' ? 'cancelled' : 'error'
+        job.error = state.error || state.message || 'Caption failed'
+        emitJob(job, { type: 'error', error: job.error, message: job.error })
+        if (record.studio2Id) {
+          const { readRecord, saveRecord } = await import('./studio2/store')
+          try {
+            const r = readRecord(record.owner, record.studio2Id)
+            r.state = job.status === 'cancelled' ? 'cancelled' : 'failed'
+            r.error = job.error
+            r.finishedAt = Date.now()
+            saveRecord(r)
+          } catch { /* record may already be gone */ }
+        }
+        await settle(job)
+        return
+      }
+      if (state.status === 'complete') {
+        const text = String(state.text || '').trim()
+        job.message = 'Caption ready'
+        job.progress = 100
+        job.status = 'complete'
+        ;(job as Job & { resultText?: string }).resultText = text
+        if (record.studio2Id) {
+          const { readRecord, saveRecord } = await import('./studio2/store')
+          const r = readRecord(record.owner, record.studio2Id)
+          r.state = 'complete'
+          r.resultText = text
+          r.finishedAt = Date.now()
+          r.savedAt = Date.now()
+          saveRecord(r)
+        }
+        writeSidecar(record.owner, record.stillId, text)
+        emitJob(job, { type: 'complete', message: 'Caption ready', progress: 100 })
+        await settle(job)
+        return
+      }
+      failures = 0
+      job.status = 'running'
+      emitJob(job, {
+        type: 'progress',
+        message: state.message || 'Captioning',
+        progress: Math.min(95, Math.max(1, Number(state.progress || 10)))
+      })
+    } catch (error) {
+      failures++
+      emitJob(job, { type: 'status', message: `Caption host check failed; retrying: ${error instanceof Error ? error.message : String(error)}` })
+      if (failures >= 10) {
+        job.status = 'error'
+        job.error = 'Caption host unreachable.'
+        emitJob(job, { type: 'error', error: job.error, message: job.error })
+        await settle(job)
+        return
+      }
+    }
+    await new Promise(resolve => setTimeout(resolve, 1500))
+  }
+  await settle(job)
+}
+
+export async function startCaptionJob(params: {
+  ownerKey: string
+  folderId: string
+  stillId: string
+  captionStyle: string
+  studio2Id?: string
+  name?: string
+}) {
+  if (!CAPTION_STYLES.includes(params.captionStyle)) throw new Error('Unknown caption style.')
+  getStill(params.ownerKey, params.stillId)
+  const job = createJob('caption')
+  job.caption = true
+  job.library = {
+    ownerKey: params.ownerKey,
+    folderId: params.folderId,
+    hideThumbnail: false,
+    name: params.name || `Describe · ${params.captionStyle}`,
+    prompt: params.captionStyle,
+    aspect: 'image',
+    width: 0,
+    height: 0,
+    steps: 1,
+    turbo: true,
+    seed: 0,
+    stillId: params.stillId,
+    engine: 'caption'
+  }
+  const record = {
+    id: job.id,
+    liveId: job.id,
+    owner: params.ownerKey,
+    stillId: params.stillId,
+    folderId: params.folderId,
+    captionStyle: params.captionStyle,
+    studio2Id: params.studio2Id,
+    createdAt: Date.now(),
+    status: 'running'
+  }
+  persist(record)
+  void (async () => {
+    try {
+      if (job.status === 'cancelled') { await settle(job); return }
+      await request(`jobs/${job.id}/input`, 'PUT', createReadStream(stillPath(params.ownerKey, params.stillId)))
+      if (job.status === 'cancelled') { await settle(job); return }
+      try {
+        await request('jobs', 'POST', { id: job.id, style: params.captionStyle })
+      } catch {
+        /* Confirm by ID; never caption twice on an HTTP timeout. */
+      }
+      await watch(job, record)
+    } catch (error) {
+      const statusCode = (error as { statusCode?: number })?.statusCode
+      if (statusCode && statusCode >= 400 && statusCode < 500) {
+        job.status = 'error'
+        job.error = error instanceof Error ? error.message : String(error)
+        emitJob(job, { type: 'error', error: job.error, message: job.error })
+        if (params.studio2Id) {
+          try {
+            const { readRecord, saveRecord } = await import('./studio2/store')
+            const r = readRecord(params.ownerKey, params.studio2Id)
+            r.state = 'failed'
+            r.error = job.error
+            r.finishedAt = Date.now()
+            saveRecord(r)
+          } catch { /* ignore */ }
+        }
+        await settle(job)
+        return
+      }
+      emitJob(job, { type: 'status', message: `Checking caption submission: ${error instanceof Error ? error.message : String(error)}` })
+      await watch(job, record)
+    }
+  })()
+  return job
+}
+
+export function resumeCaptionJobs() {
+  if (!existsSync(pendingRoot())) return
+  for (const file of readdirSync(pendingRoot()).filter(file => /^[a-zA-Z0-9-]+\.json$/.test(file))) {
+    try {
+      const record = JSON.parse(readFileSync(join(pendingRoot(), file), 'utf8'))
+      if (getJob(record.id)) continue
+      const job = restoreJob({
+        id: record.liveId || record.id,
+        clientId: record.clientId || crypto.randomUUID(),
+        promptId: '',
+        startedAt: record.createdAt || Date.now(),
+        library: {
+          ownerKey: record.owner,
+          folderId: record.folderId,
+          hideThumbnail: false,
+          prompt: record.captionStyle || 'descriptive',
+          aspect: 'image',
+          width: 0,
+          height: 0,
+          steps: 1,
+          turbo: true,
+          seed: 0,
+          stillId: record.stillId,
+          engine: 'caption'
+        }
+      })
+      job.caption = true
+      job.kind = 'caption'
+      job.message = 'Reconnecting to caption host'
+      void watch(job, record)
+    } catch { /* Preserve invalid records for diagnosis. */ }
+  }
+}
diff --git a/server/utils/jobs.ts b/server/utils/jobs.ts
index bd25f78..3ed3ada 100644
--- a/server/utils/jobs.ts
+++ b/server/utils/jobs.ts
@@ -36,9 +36,11 @@ export interface Job {
   upscale?: boolean
   yueGp?: boolean
   yue2?: boolean
+  caption?: boolean
+  resultText?: string
   musicActivity?: { checkedAt: number; running: boolean }
   id: string
-  kind?: 'video' | 'edit' | 'music'
+  kind?: 'video' | 'edit' | 'music' | 'caption'
   promptId?: string
   clientId: string
   status: JobStatus
diff --git a/server/utils/studioQueue.ts b/server/utils/studioQueue.ts
index 1228c7f..320f391 100644
--- a/server/utils/studioQueue.ts
+++ b/server/utils/studioQueue.ts
@@ -13,7 +13,7 @@ import { imageV2StackSpecials } from '~/utils/imageV2'
 import { allowIdentityRefs, type PermanenceRef } from '~/utils/globalLocks'
 
 export type StudioJobStatus = 'waiting' | 'running' | 'held' | 'complete' | 'error' | 'cancelled'
-export type StudioJobKind = 'video' | 'edit' | 'music'
+export type StudioJobKind = 'video' | 'edit' | 'music' | 'caption'
 
 export interface StudioJobPayload {
   studio2Id?: string
@@ -40,6 +40,7 @@ export interface StudioJobPayload {
   useIdentityRefs: boolean
   stillId?: string
   stillFilename?: string
+  captionStyle?: string
   hideThumbnail: boolean
   hideInput?: boolean
   folderLocked?: boolean
@@ -224,6 +225,7 @@ export function listStudioJobs(owner: string) {
 export function studioJobKind(job: Pick<StudioJob, 'kind'> | { kind?: string }) {
   if (job.kind === 'edit') return 'edit'
   if (job.kind === 'music') return 'music'
+  if (job.kind === 'caption') return 'caption'
   return 'video'
 }
 
@@ -288,7 +290,7 @@ function failZombieLiveJob(job: Job, error: string) {
 function sweepStaleLiveJobs() {
   const now = Date.now()
   for (const job of listJobs()) {
-    if (job.studio2 || job.yueGp || job.yue2 || job.upscale) continue
+    if (job.studio2 || job.yueGp || job.yue2 || job.upscale || job.caption) continue
     if (job.saving) continue
     if (job.status === 'queued' && !job.promptId && now - job.startedAt >= QUEUED_GRACE_MS) {
       failZombieLiveJob(job, 'Job never started')
@@ -308,12 +310,12 @@ async function reapZombieLiveJobs() {
   const { fetchHistory } = await import('~/server/utils/comfy')
   for (const job of listJobs()) {
     // Never interrupt download/stitch/library save — Comfy is idle then by design.
-    if (job.studio2 || job.yueGp || job.yue2 || job.upscale) continue
+    if (job.studio2 || job.yueGp || job.yue2 || job.upscale || job.caption) continue
     if (job.saving) continue
     if (job.library?.chainContinuing) continue
     if (job.status !== 'running' && job.status !== 'uploading' && job.status !== 'queued') continue
     if (jobIsLocallySubmitting(job)) continue
-    const zombieMs = (job.kind === 'edit' || job.kind === 'music') ? 45_000 : ZOMBIE_EMPTY_COMFY_MS
+    const zombieMs = (job.kind === 'edit' || job.kind === 'music' || job.kind === 'caption') ? 45_000 : ZOMBIE_EMPTY_COMFY_MS
     if (jobAgeMs(job) < zombieMs) continue
     if (!job.promptId) {
       if (jobAgeMs(job) >= QUEUED_GRACE_MS) failZombieLiveJob(job, 'Job never started on ComfyUI')
@@ -353,7 +355,7 @@ async function reapZombieLiveJobs() {
 }
 
 function liveJobOwnsGpu(job: Job) {
-  if ((job.studio2 || job.yueGp || job.yue2 || job.upscale) && ['running', 'queued', 'uploading'].includes(job.status)) return true
+  if ((job.studio2 || job.yueGp || job.yue2 || job.upscale || job.caption) && ['running', 'queued', 'uploading'].includes(job.status)) return true
   if (job.library?.stopAfterCurrent) return false
   if (job.library?.chainContinuing) return true
   if (job.saving) return true
@@ -373,7 +375,7 @@ function liveJobOwnsGpu(job: Job) {
  */
 function clearDeadGpuClaimsForForceStart() {
   for (const live of listJobs()) {
-    if (live.studio2 || live.yueGp || live.yue2 || live.upscale) continue
+    if (live.studio2 || live.yueGp || live.yue2 || live.upscale || live.caption) continue
     if (live.saving) continue
     if (jobIsLocallySubmitting(live)) continue
     if (live.status !== 'running' && live.status !== 'queued' && live.status !== 'uploading') {
@@ -467,8 +469,11 @@ export async function addStudioJob(params: {
   kind?: StudioJobKind
 }) {
   const now = Date.now()
-  const kind = params.kind === 'edit' ? 'edit' : params.kind === 'music' ? 'music' : 'video'
-  const shotCount = kind === 'music'
+  const kind = params.kind === 'edit' ? 'edit'
+    : params.kind === 'music' ? 'music'
+      : params.kind === 'caption' ? 'caption'
+        : 'video'
+  const shotCount = kind === 'music' || kind === 'caption'
     ? 1
     : kind === 'edit'
       ? 1 + (params.payload.passes?.length || 0)
@@ -604,6 +609,10 @@ export async function clearStuckStudioWork(owner: string) {
       const { cancelYue2Job } = await import('./yue2')
       await cancelYue2Job(job)
     }
+    if (job.caption) {
+      const { cancelCaptionJob } = await import('./caption')
+      await cancelCaptionJob(job)
+    }
     job.status = 'cancelled'
     job.error = 'Cleared by force reset'
     if (job.library) {
@@ -676,6 +685,11 @@ async function stopLiveGeneration(liveJobId?: string, shotQueueId?: string) {
     await cancelYue2Job(live)
     return
   }
+  if (live?.caption) {
+    const { cancelCaptionJob } = await import('./caption')
+    await cancelCaptionJob(live)
+    return
+  }
   if (live) {
     live.status = 'cancelled'
     if (live.library) {
@@ -887,6 +901,10 @@ function pendingAlive(job: StudioJob) {
       const root = join(String(useRuntimeConfig().libraryDir || process.env.LIBRARY_DIR || '/data/library'), 'yue2-pending', `${job.liveJobId}.json`)
       if (existsSync(root)) return true
     }
+    if (job.kind === 'caption') {
+      const root = join(String(useRuntimeConfig().libraryDir || process.env.LIBRARY_DIR || '/data/library'), 'caption-pending', `${job.liveJobId}.json`)
+      if (existsSync(root)) return true
+    }
   }
   if (!job.shotQueueId) return false
   return listPendingJobs().some(pending => (
@@ -1395,6 +1413,42 @@ async function startStudioExtendJob(item: StudioJob) {
   }
 }
 
+async function startStudioCaptionJob(item: StudioJob) {
+  let live: import('~/server/utils/jobs').Job | undefined
+  try {
+    const { startCaptionJob } = await import('./caption')
+    const style = String(item.payload.captionStyle || 'descriptive')
+    const stillId = String(item.payload.stillId || '')
+    if (!stillId) throw new Error('Caption requires a still.')
+    live = await startCaptionJob({
+      ownerKey: item.ownerKey,
+      folderId: item.payload.folderId,
+      stillId,
+      captionStyle: style,
+      studio2Id: item.payload.studio2Id,
+      name: item.payload.name
+    })
+    await markStudioLive(item.ownerKey, item.id, live.id)
+    if (item.payload.studio2Id) {
+      const { readRecord, saveRecord } = await import('./studio2/store')
+      const record = readRecord(item.ownerKey, item.payload.studio2Id)
+      record.state = 'rendering'
+      record.liveId = live.id
+      record.startedAt = Date.now()
+      record.updatedAt = Date.now()
+      saveRecord(record)
+    }
+  } 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 parkStudioOnStartFailure(item.ownerKey, item.id, message)
+    kickStudioQueue()
+  }
+}
+
 async function startStudioMusicJob(item: StudioJob) {
   let live: import('~/server/utils/jobs').Job | undefined
   try {
@@ -1437,6 +1491,10 @@ export async function startStudioJob(item: StudioJob) {
 }
 
 async function startStudioJobReserved(item: StudioJob) {
+  if (studioJobKind(item) === 'caption') {
+    await startStudioCaptionJob(item)
+    return
+  }
   if (item.payload.studio2Id) {
     try {
       const { startStudio2Job } = await import('./studio2/runner')
@@ -1701,7 +1759,7 @@ export async function onLiveVideoSettled(job: Job) {
     return
   }
   const remaining = remainingStudioShots(job)
-  const wakeFail = !job.studio2 && !job.yueGp && !job.yue2 && !job.upscale && job.status === 'error' && remaining > 0 && isTransientComfyError(job.error)
+  const wakeFail = !job.studio2 && !job.yueGp && !job.yue2 && !job.upscale && !job.caption && job.status === 'error' && remaining > 0 && isTransientComfyError(job.error)
   const failed = (job.status === 'error' || job.status === 'cancelled') && !wakeFail
 
   await mutateStore(owner, (store) => {
diff --git a/shared/studio2/caption.mjs b/shared/studio2/caption.mjs
new file mode 100644
index 0000000..4548f76
--- /dev/null
+++ b/shared/studio2/caption.mjs
@@ -0,0 +1,66 @@
+export const CAPTION_STYLES = ['descriptive', 'klein_prompt', 'delta', 'tags']
+
+export const DELTA_LOCKED_LOOK =
+  'short light-brown bob, pink tank, light blue shorts, open green Slytherin robe with red-gold trim, barefoot'
+
+export function captionStylePrompt(style) {
+  switch (style) {
+    case 'klein_prompt':
+      return 'Write one self-contained image generation prompt for Flux Klein. Include subject, pose, clothing, setting, lighting, and camera. No preamble or quotes.'
+    case 'delta':
+      return `The character's locked baseline look is: ${DELTA_LOCKED_LOOK}. Describe ONLY what changed from that baseline in this image. Do not restate the locked look.`
+    case 'tags':
+      return 'List comma-separated descriptive tags for this image. Tags only, no sentences.'
+    case 'descriptive':
+    default:
+      return 'Describe this image in clear, detailed prose. Cover subject, appearance, clothing, pose, setting, and lighting.'
+  }
+}
+
+export function validateCaptionRequest(raw) {
+  const fail = message => { throw Object.assign(new Error(message), { statusCode: 400 }) }
+  const body = raw || {}
+  const style = String(body.captionStyle || body.style || 'descriptive')
+  if (!CAPTION_STYLES.includes(style)) fail('Unknown caption style.')
+  const folderId = String(body.folderId || '')
+  if (!folderId) fail('Choose a folder.')
+  const stillId = String(body.stillId || body.imageAId || '')
+  const sourcePath = String(body.sourcePath || '')
+  if (!stillId && !sourcePath) fail('Choose a still to describe.')
+  return {
+    mode: 'caption',
+    folderId,
+    stillId,
+    sourcePath,
+    captionStyle: style,
+    promptSections: { action: `Describe · ${style}` },
+    compiledPrompt: captionStylePrompt(style),
+    engine: 'caption',
+    imageStyles: { positive: [], negative: [] },
+    hideOutput: false,
+    lockFace: false,
+    lockOutfit: false,
+    hideInput: false,
+    identityStillId: '',
+    imageAId: stillId,
+    imageBId: '',
+    maskId: '',
+    startClipId: '',
+    endStillId: '',
+    guides: [],
+    batch: [],
+    settings: {
+      aspect: 'auto',
+      fps: 24,
+      width: 0,
+      height: 0,
+      steps: 1,
+      cfg: 0,
+      seedMode: 'random',
+      seed: 0,
+      duration: 0,
+      turbo: true,
+      loraStack: []
+    }
+  }
+}
diff --git a/shared/studio2/status.mjs b/shared/studio2/status.mjs
index 22cee85..91d8212 100644
--- a/shared/studio2/status.mjs
+++ b/shared/studio2/status.mjs
@@ -1,4 +1,4 @@
-export function gpuStatus(jobs, health, upscales=[], musicJobs=[]) {
+export function gpuStatus(jobs, health, upscales=[], musicJobs=[], captionJobs=[]) {
  if (!health) return {label:'Status unavailable',tone:'unknown',detail:'Checking GPU connection…'}
  const upscale=upscales.find(j=>j.status==='running')
  if(upscale)return {label:'Upscaling',tone:'busy',detail:upscale.name || 'Video upscale'}
@@ -7,6 +7,9 @@ export function gpuStatus(jobs, health, upscales=[], musicJobs=[]) {
   const stage=music.live?.message || music.live?.stage || music.waitReason || 'YuE2'
   return {label:music.status==='waiting'?'Queued':'Generating',tone:'busy',detail:String(stage)}
  }
+ const caption=captionJobs.find(j=>['waiting','waking','submitting','rendering','saving'].includes(j.state) || j.state==='queued' || j.state==='held')
+ if(caption)return {label:caption.state==='waiting'?'Queued':'Describing',tone:'busy',detail:caption.request?.captionStyle || 'Caption'}
+ if(health.caption?.busy)return {label:'Describing',tone:'busy',detail:'Caption model is using the GPU'}
  if(health.yue2?.busy)return {label:'Generating',tone:'busy',detail:'YuE2 is using the GPU'}
  const job=jobs.find(j=>['waking','submitting','rendering','saving'].includes(j.state))
  if(job)return {label:{waking:'Waking up',submitting:'Submitting',rendering:'Generating',saving:'Saving'}[job.state],tone:'busy',detail:job.request?.promptSections?.action || 'Generation in progress'}
diff --git a/tests/caption.test.mjs b/tests/caption.test.mjs
new file mode 100644
index 0000000..04b8c5a
--- /dev/null
+++ b/tests/caption.test.mjs
@@ -0,0 +1,139 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { EventEmitter } from 'node:events'
+import { PassThrough } from 'node:stream'
+import { mkdtempSync, writeFileSync, readFileSync, mkdirSync, existsSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { createCaptionHost, validateCaptionHostRequest, captionModelFiles } from '../scripts/caption-host.mjs'
+import { validateCaptionRequest, captionStylePrompt, CAPTION_STYLES, DELTA_LOCKED_LOOK } from '../shared/studio2/caption.mjs'
+
+test('caption styles and delta lock text', () => {
+  assert.deepEqual(CAPTION_STYLES, ['descriptive', 'klein_prompt', 'delta', 'tags'])
+  assert.match(captionStylePrompt('delta'), new RegExp(DELTA_LOCKED_LOOK))
+  assert.match(captionStylePrompt('klein_prompt'), /Flux Klein/)
+  assert.match(captionStylePrompt('tags'), /comma-separated/)
+})
+
+test('validateCaptionRequest requires folder + still', () => {
+  assert.throws(() => validateCaptionRequest({}), /folder/)
+  assert.throws(() => validateCaptionRequest({ folderId: 'f1' }), /still/)
+  assert.throws(() => validateCaptionRequest({ folderId: 'f1', stillId: 's1', captionStyle: 'nope' }), /style/)
+  const ok = validateCaptionRequest({ folderId: 'f1', stillId: 's1', captionStyle: 'descriptive' })
+  assert.equal(ok.mode, 'caption')
+  assert.equal(ok.captionStyle, 'descriptive')
+  assert.equal(ok.lockFace, false)
+  assert.equal(ok.lockOutfit, false)
+})
+
+test('host validates job body', () => {
+  assert.throws(() => validateCaptionHostRequest({ id: 'bad', style: 'descriptive' }))
+  assert.deepEqual(
+    validateCaptionHostRequest({ id: 'caption-job-123456', style: 'tags' }),
+    { id: 'caption-job-123456', style: 'tags', imagePath: '' }
+  )
+})
+
+function fixture() {
+  const root = mkdtempSync(join(tmpdir(), 'aigen-caption-'))
+  const models = join(root, 'models')
+  mkdirSync(models)
+  writeFileSync(join(models, captionModelFiles.model), 'model')
+  writeFileSync(join(models, captionModelFiles.mmproj), 'mmproj')
+  const llama = join(root, 'llama-server.exe')
+  writeFileSync(llama, '')
+  const dataDir = join(root, 'jobs')
+  const child = new EventEmitter()
+  child.pid = 4242
+  child.stdout = new PassThrough()
+  child.stderr = new PassThrough()
+  child.kill = () => { setImmediate(() => child.emit('close', 0)); return true }
+  child.exitCode = null
+  const calls = []
+  let fetchCount = 0
+  const fetchImpl = async (url, init) => {
+    fetchCount++
+    if (String(url).endsWith('/health')) return { ok: true }
+    if (String(url).includes('/v1/chat/completions')) {
+      assert.match(JSON.stringify(JSON.parse(init.body)), /Describe this image|Flux Klein|locked baseline|comma-separated/)
+      return {
+        ok: true,
+        json: async () => ({ choices: [{ message: { content: 'a warm caption' } }] })
+      }
+    }
+    throw new Error(`unexpected fetch ${url}`)
+  }
+  const host = createCaptionHost({
+    modelsDir: models,
+    llamaServer: llama,
+    dataDir,
+    prepare: async () => {},
+    leaseValid: () => true,
+    spawnProcess: (...args) => { calls.push(args); setImmediate(() => {}); return child },
+    fetchImpl
+  })
+  return { host, child, calls, root, dataDir, fetchCount: () => fetchCount }
+}
+
+test('host loads llama-server, captions once, and unloads', async () => {
+  const f = fixture()
+  const jobDir = join(f.dataDir, 'caption-job-123456')
+  mkdirSync(jobDir, { recursive: true })
+  writeFileSync(join(jobDir, 'input.png'), Buffer.alloc(64, 1))
+  const started = f.host.start({ id: 'caption-job-123456', style: 'descriptive' }, 'lease')
+  // Let the host reach waitForServer / chat completion.
+  await new Promise(r => setTimeout(r, 50))
+  f.child.emit('spawn')
+  const result = await started
+  assert.equal(result.status, 'complete')
+  assert.equal(result.text, 'a warm caption')
+  assert.equal(f.calls.length, 1)
+  const [, args] = f.calls[0]
+  assert.ok(args.includes('--mmproj'))
+  assert.ok(args.includes('-m'))
+  assert.equal(f.host.read('caption-job-123456').text, 'a warm caption')
+  // busy may briefly remain true during the post-unload hold window
+  assert.ok(typeof f.host.busy() === 'boolean')
+})
+
+test('host rejects a second job while busy', async () => {
+  const f = fixture()
+  const dataDir = join(f.root, 'jobs2')
+  let resolveHealth
+  const healthGate = new Promise(resolve => { resolveHealth = resolve })
+  const hung = createCaptionHost({
+    modelsDir: join(f.root, 'models'),
+    llamaServer: join(f.root, 'llama-server.exe'),
+    dataDir,
+    prepare: async () => {},
+    leaseValid: () => true,
+    spawnProcess: () => {
+      const child = new EventEmitter()
+      child.pid = 99
+      child.stdout = new PassThrough()
+      child.stderr = new PassThrough()
+      child.kill = () => { setImmediate(() => child.emit('close', 1)); return true }
+      child.exitCode = null
+      return child
+    },
+    fetchImpl: async (url) => {
+      if (String(url).endsWith('/health')) {
+        await healthGate
+        return { ok: true }
+      }
+      return { ok: true, json: async () => ({ choices: [{ message: { content: 'x' } }] }) }
+    }
+  })
+  mkdirSync(join(dataDir, 'caption-job-aaaaaa'), { recursive: true })
+  writeFileSync(join(dataDir, 'caption-job-aaaaaa', 'input.png'), Buffer.alloc(64, 1))
+  const first = hung.start({ id: 'caption-job-aaaaaa', style: 'tags' }, 'lease')
+  await new Promise(r => setTimeout(r, 20))
+  await assert.rejects(hung.start({ id: 'caption-job-bbbbbb', style: 'tags' }, 'lease'), /already running/)
+  await hung.cancel('caption-job-aaaaaa')
+  resolveHealth()
+  await assert.rejects(first)
+})
+
+test('POST /caption sync shape is documented on host module', () => {
+  assert.equal(typeof createCaptionHost({ prepare: async () => {}, leaseValid: () => true }).captionOnce, 'function')
+})