Caption Generator Download

Turn a 3-minute YouTube tutorial video into 1080p captioned video files just by typing what you need. Whether it's adding downloadable captions to videos aut...

Security Scan

The skill's behavior (uploading videos to a cloud backend and obtaining/using NEMO_TOKENs) matches its captioning purpose, but metadata and instruction inconsistencies and automated token creation are concerning and deserve review before installing.

Purpose & Capability

The declared primary credential (NEMO_TOKEN) and the runtime instructions (upload video, call mega-api-prod.nemovideo.ai endpoints, render/export) are coherent with a cloud captioning/encoding service. However, SKILL.md frontmatter references a config path (~/.config/nemovideo/) that the registry metadata did not list, and the skill both declares NEMO_TOKEN as required and instructs the agent to obtain an anonymous token automatically if NEMO_TOKEN is absent — an internal inconsistency about whether a pre-set token is actually required.

Instruction Scope

Instructions are narrowly focused on the captioning workflow: start sessions, upload files, stream SSE messages, and request renders. The agent is instructed to upload user media and to include specific attribution headers and bearer tokens — all expected for a cloud processing workflow. There is no instruction to read unrelated system files, other credentials, or to exfiltrate data outside the stated backend; however, the agent will transmit user-supplied media and metadata to the external domain.

Install Mechanism

This is an instruction-only skill with no install spec and no code files — lowest install risk. Nothing is written to disk by an installer in the provided materials.

Credentials

Only NEMO_TOKEN is declared as required, which is proportionate to the service. But the skill's instructions permit automatic creation of an anonymous NEMO_TOKEN via an API call (100 free credits, 7-day expiry), meaning the env-var requirement is ambiguous. The frontmatter's config path (not listed in registry metadata) also suggests possible access to a local config location. Users should note the skill will send Authorization: Bearer <NEMO_TOKEN> (whether provided by them or obtained anonymously) with every API call.

Persistence & Privilege

always:false and no install hooks are present. The skill does not request permanent platform presence or modifications to other skill settings.

What to consider before installing

Before installing, confirm you trust the external service domain (mega-api-prod.nemovideo.ai) and understand that any video you drop will be uploaded and processed on that third‑party backend. Note the skill can obtain an anonymous token on your behalf (100 free credits, 7‑day expiry) — decide if you prefer to provide your own NEMO_TOKEN or allow anonymous issuance. The SKILL.md references a local config path (~/.config/nemovideo/) that the registry did not list; ask the publisher why that path is needed. Avoid uploading sensitive or regulated content until you verify the service's privacy/retention policy and billing/credit implications (exports may be blocked without registration/paid tier). If you need higher assurance, request the publisher's homepage, privacy policy, or source code, or prefer a skill hosted by a known vendor.

Getting Started

Ready when you are. Drop your video files here or describe what you want to make.

Try saying:

• "generate a 3-minute YouTube tutorial video into a 1080p MP4"
• "generate and burn in captions in English, then download the captioned MP4"
• "adding downloadable captions to videos automatically for content creators"

Quick Start Setup

This skill connects to a cloud processing backend. On first use, set up the connection automatically and let the user know ("Connecting...").

Token check: Look for NEMO_TOKEN in the environment. If found, skip to session creation. Otherwise:

• Generate a UUID as client identifier
• POST https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token with X-Client-Id header
• Extract data.token from the response — this is your NEMO_TOKEN (100 free credits, 7-day expiry)

Session: POST https://mega-api-prod.nemovideo.ai/api/tasks/me/with-session/nemo_agent with Bearer auth and body {"task_name":"project"}. Keep the returned session_id for all operations.

Let the user know with a brief "Ready!" when setup is complete. Don't expose tokens or raw API output.

Caption Generator Download — Generate Captions and Download Videos

Drop your video files in the chat and tell me what you need. I'll handle the AI subtitle generation on cloud GPUs — you don't need anything installed locally.

Here's a typical use: you send a a 3-minute YouTube tutorial video, ask for generate and burn in captions in English, then download the captioned MP4, and about 30-60 seconds later you've got a MP4 file ready to download. The whole thing runs at 1080p by default.

One thing worth knowing — shorter clips under 2 minutes produce captions faster and with higher accuracy.

Matching Input to Actions

User prompts referencing caption generator download, aspect ratio, text overlays, or audio tracks get routed to the corresponding action via keyword and intent classification.

User says...	Action	Skip SSE?
"export" / "导出" / "download" / "send me the video"	→ §3.5 Export	✅
"credits" / "积分" / "balance" / "余额"	→ §3.3 Credits	✅
"status" / "状态" / "show tracks"	→ §3.4 State	✅
"upload" / "上传" / user sends file	→ §3.2 Upload	✅
Everything else (generate, edit, add BGM…)	→ §3.1 SSE	❌

Cloud Render Pipeline Details

Each export job queues on a cloud GPU node that composites video layers, applies platform-spec compression (H.264, up to 1080x1920), and returns a download URL within 30-90 seconds. The session token carries render job IDs, so closing the tab before completion orphans the job.

Base URL: https://mega-api-prod.nemovideo.ai

Endpoint	Method	Purpose
/api/tasks/me/with-session/nemo_agent	POST	Start a new editing session. Body: {"task_name":"project","language":"<lang>"}. Returns session_id.
/run_sse	POST	Send a user message. Body includes app_name, session_id, new_message. Stream response with Accept: text/event-stream. Timeout: 15 min.
/api/upload-video/nemo_agent/me/<sid>	POST	Upload a file (multipart) or URL.
/api/credits/balance/simple	GET	Check remaining credits (available, frozen, total).
/api/state/nemo_agent/me/<sid>/latest	GET	Fetch current timeline state (draft, video_infos, generated_media).
/api/render/proxy/lambda	POST	Start export. Body: {"id":"render_<ts>","sessionId":"<sid>","draft":<json>,"output":{"format":"mp4","quality":"high"}}. Poll status every 30s.

Accepted file types: mp4, mov, avi, webm, mkv, jpg, png, gif, webp, mp3, wav, m4a, aac.

Three attribution headers are required on every request and must match this file's frontmatter:

Header	Value
X-Skill-Source	caption-generator-download
X-Skill-Version	frontmatter version
X-Skill-Platform	auto-detect: clawhub / cursor / unknown from install path

Every API call needs Authorization: Bearer <NEMO_TOKEN> plus the three attribution headers above. If any header is missing, exports return 402.

Error Handling

Code	Meaning	Action
0	Success	Continue
1001	Bad/expired token	Re-auth via anonymous-token (tokens expire after 7 days)
1002	Session not found	New session §3.0
2001	No credits	Anonymous: show registration URL with ?bind=<id> (get <id> from create-session or state response when needed). Registered: "Top up credits in your account"
4001	Unsupported file	Show supported formats
4002	File too large	Suggest compress/trim
400	Missing X-Client-Id	Generate Client-Id and retry (see §1)
402	Free plan export blocked	Subscription tier issue, NOT credits. "Register or upgrade your plan to unlock export."
429	Rate limit (1 token/client/7 days)	Retry in 30s once

SSE Event Handling

Event	Action
Text response	Apply GUI translation (§4), present to user
Tool call/result	Process internally, don't forward
heartbeat / empty data:	Keep waiting. Every 2 min: "⏳ Still working..."
Stream closes	Process final response

~30% of editing operations return no text in the SSE stream. When this happens: poll session state to verify the edit was applied, then summarize changes to the user.

Translating GUI Instructions

The backend responds as if there's a visual interface. Map its instructions to API calls:

• "click" or "点击" → execute the action via the relevant endpoint
• "open" or "打开" → query session state to get the data
• "drag/drop" or "拖拽" → send the edit command through SSE
• "preview in timeline" → show a text summary of current tracks
• "Export" or "导出" → run the export workflow

Draft field mapping: t=tracks, tt=track type (0=video, 1=audio, 7=text), sg=segments, d=duration(ms), m=metadata.

Timeline (3 tracks): 1. Video: city timelapse (0-10s) 2. BGM: Lo-fi (0-10s, 35%) 3. Title: "Urban Dreams" (0-3s)

Tips and Tricks

The backend processes faster when you're specific. Instead of "make it look better", try "generate and burn in captions in English, then download the captioned MP4" — concrete instructions get better results.

Max file size is 500MB. Stick to MP4, MOV, AVI, WebM for the smoothest experience.

Export as MP4 for widest compatibility across platforms and devices.

Common Workflows

Quick edit: Upload → "generate and burn in captions in English, then download the captioned MP4" → Download MP4. Takes 30-60 seconds for a 30-second clip.

Batch style: Upload multiple files in one session. Process them one by one with different instructions. Each gets its own render.

Iterative: Start with a rough cut, preview the result, then refine. The session keeps your timeline state so you can keep tweaking.