Subtitle Generator Chrome

generate video files into captioned video files with this skill. Works with MP4, MOV, AVI, WebM files up to 500MB. YouTubers and content creators use it for...

Security Scan

The skill's behavior (uploading user videos and using an external API token) matches its stated purpose, but there are metadata inconsistencies, no provenance for the external service, and clear data-exfiltration/privacy implications that you should understand before using it.

Purpose & Capability

The skill claims to generate/burn subtitles and all runtime instructions are focused on uploading video files and invoking a remote rendering/subtitle API — that is coherent. However, the SKILL.md frontmatter declares a configPath (~/.config/nemovideo/) while the registry metadata lists no required config paths. This mismatch should be explained by the author.

Instruction Scope

Runtime instructions direct the agent to obtain or use a NEMO_TOKEN (or request an anonymous token), create sessions, upload user files (multipart or URLs), and poll/pull rendered outputs from mega-api-prod.nemovideo.ai. Uploading arbitrary user video/audio to a third-party API is expected for this skill but is a privacy/data-exfiltration action — the SKILL.md gives the agent authority to transmit user-provided media off-host. The instructions also tell the agent to persist session_id and to auto-detect an install path for X-Skill-Platform; reading install paths or config files could surface additional local data if implemented.

Install Mechanism

This is instruction-only (no install spec, no code files), so nothing is written to disk by an install script. That reduces supply-chain risk.

Credentials

The skill requires a single API credential (NEMO_TOKEN) as its primary env var — that matches a cloud API integration. However, the SKILL.md frontmatter references a config path (~/.config/nemovideo/) not declared in the registry metadata; if the agent reads that path it could access stored tokens or configs beyond the single declared env var. Also, anonymous-token creation is supported, which will create short-lived credentials automatically.

Persistence & Privilege

always is false and the skill is user-invocable; normal autonomous invocation is allowed. The only persistence indicated is saving session_id from the remote API, which is bounded to this skill's sessions and is reasonable for job tracking.

What to consider before installing

This skill will upload whatever video/audio you provide to an external service (mega-api-prod.nemovideo.ai) and requires an API token (NEMO_TOKEN) or will mint an anonymous token for you. That behavior is consistent with a cloud subtitle renderer but has privacy implications: do not use it for sensitive or private footage unless you trust the service. Two red flags to consider before installing: (1) the skill has no homepage or known source/owner details — you can't verify the provider; (2) the SKILL.md mentions a config path (~/.config/nemovideo/) that isn't declared in registry metadata — confirm whether the skill will read local config files. If you proceed, prefer the anonymous-token flow, limit the content you upload, and ask the publisher for provenance/terms/privacy details and why the configPath discrepancy exists.

Getting Started

Send me your video files and I'll handle the subtitle generation. Or just describe what you're after.

Try saying:

• "generate a 3-minute YouTube video in MP4 format into a 1080p MP4"
• "generate and burn in English subtitles for my video"
• "adding subtitles to videos without a Chrome extension for YouTubers and content creators"

Automatic Setup

On first interaction, connect to the processing API before doing anything else. Show a brief status like "Setting things up...".

Token: If NEMO_TOKEN environment variable is already set, use it and skip to Session below.

Free token: Generate a UUID as client identifier, then POST to https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token with header X-Client-Id: <uuid>. The response field data.token becomes your NEMO_TOKEN (100 credits, 7-day expiry).

Session: POST to https://mega-api-prod.nemovideo.ai/api/tasks/me/with-session/nemo_agent with Bearer auth and body {"task_name":"project"}. Save session_id from the response.

Confirm to the user you're connected and ready. Don't print tokens or raw JSON.

Subtitle Generator Chrome — Generate Subtitles for Any Video

Send me your video files and describe the result you want. The subtitle generation runs on remote GPU nodes — nothing to install on your machine.

A quick example: upload a 3-minute YouTube video in MP4 format, type "generate and burn in English subtitles for my video", and you'll get a 1080p MP4 back in roughly 30-60 seconds. All rendering happens server-side.

Worth noting: shorter clips under 5 minutes generate subtitles significantly faster.

Matching Input to Actions

User prompts referencing subtitle generator chrome, 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.

All requests must include: Authorization: Bearer <NEMO_TOKEN>, X-Skill-Source, X-Skill-Version, X-Skill-Platform. Missing attribution headers will cause export to fail with 402.

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

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

API base: https://mega-api-prod.nemovideo.ai

Create session: POST /api/tasks/me/with-session/nemo_agent — body {"task_name":"project","language":"<lang>"} — returns task_id, session_id.

Send message (SSE): POST /run_sse — body {"app_name":"nemo_agent","user_id":"me","session_id":"<sid>","new_message":{"parts":[{"text":"<msg>"}]}} with Accept: text/event-stream. Max timeout: 15 minutes.

Upload: POST /api/upload-video/nemo_agent/me/<sid> — file: multipart -F "files=@/path", or URL: {"urls":["<url>"],"source_type":"url"}

Credits: GET /api/credits/balance/simple — returns available, frozen, total

Session state: GET /api/state/nemo_agent/me/<sid>/latest — key fields: data.state.draft, data.state.video_infos, data.state.generated_media

Export (free, no credits): POST /api/render/proxy/lambda — body {"id":"render_<ts>","sessionId":"<sid>","draft":<json>,"output":{"format":"mp4","quality":"high"}}. Poll GET /api/render/proxy/lambda/<id> every 30s until status = completed. Download URL at output.url.

Supported formats: mp4, mov, avi, webm, mkv, jpg, png, gif, webp, mp3, wav, m4a, aac.

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

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

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.

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)

Common Workflows

Quick edit: Upload → "generate and burn in English subtitles for my video" → 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.

Tips and Tricks

The backend processes faster when you're specific. Instead of "make it look better", try "generate and burn in English subtitles for my video" — 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 browsers.