Ai Subtitle Extension

add 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 addin...

Security Scan

The skill's declared purpose (cloud subtitle generation) matches most of its runtime instructions, but there are small mismatches and privacy-surface concerns (declared config path access, install-path detection, and an unknown upstream service) that warrant caution before installing.

Purpose & Capability

Name and description align with the instructions: the skill uploads videos to a cloud backend (nemovideo) to generate subtitles and export MP4s. Requesting a single service token (NEMO_TOKEN) is consistent with a cloud-rendering service.

Instruction Scope

Instructions require reading NEMO_TOKEN from the environment (expected) and, if missing, create an anonymous token by calling an external API. The SKILL instructs deriving an X-Skill-Platform header from the agent's install path (mentions ~/.clawhub/ and ~/.cursor/skills/), which implies inspecting the agent filesystem/paths. The YAML frontmatter also lists a config path (~/.config/nemovideo/) even though runtime instructions don't clearly explain reading it — this mismatch increases the chance the skill will access local config files or paths beyond what's needed for a single API session.

Install Mechanism

Instruction-only skill with no install spec and no code files; nothing is written to disk by an installer. This is the lowest install-risk category.

Credentials

Only one credential is requested (NEMO_TOKEN), which is proportionate for a cloud rendering/subtitle service. However, the metadata's configPaths (~/.config/nemovideo/) suggests the skill may also want to read local configuration files — that broader file access is not justified in the prose and could expose other local secrets if present.

Persistence & Privilege

Skill is not marked always:true and does not request permanent platform-wide privileges. It does perform autonomous API calls as normal for an instruction skill, but nothing indicates it modifies other skills or global config.

What to consider before installing

This skill appears to do what it says (upload videos to a nemo-video cloud API and return subtitled MP4s) but exercise caution: 1) The skill will call an external domain (mega-api-prod.nemovideo.ai) — verify you trust that service before uploading sensitive videos. 2) It asks for NEMO_TOKEN; prefer giving a limited/anonymous token if available rather than a long-lived account token. 3) Metadata lists a config path (~/.config/nemovideo/) and the skill computes an X-Skill-Platform value from install paths — ask the author whether the skill will read files under your home directory and why. 4) Because there is no source/homepage, consider seeking a published source or vendor documentation (privacy policy, retention of uploaded videos) before installing. If you need stronger assurance, request the skill author to: (a) remove any unnecessary configPaths, (b) explicitly state whether local files are read, and (c) provide a homepage or repository for review.

Getting Started

Share your video files and I'll get started on AI subtitle generation. Or just tell me what you're thinking.

Try saying:

• "add my video files"
• "export 1080p MP4"
• "extend and auto-generate subtitles for the"

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.

AI Subtitle Extension — Generate and Extend Video Subtitles

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 extend and auto-generate subtitles for the full video in English, 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 — splitting long videos into segments can improve subtitle sync accuracy.

Matching Input to Actions

User prompts referencing ai subtitle extension, 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.

Headers are derived from this file's YAML frontmatter. X-Skill-Source is ai-subtitle-extension, X-Skill-Version comes from the version field, and X-Skill-Platform is detected from the install path (~/.clawhub/ = clawhub, ~/.cursor/skills/ = cursor, otherwise unknown).

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.

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.

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.

Backend Response Translation

The backend assumes a GUI exists. Translate these into API actions:

Backend says	You do
"click [button]" / "点击"	Execute via API
"open [panel]" / "打开"	Query session state
"drag/drop" / "拖拽"	Send edit via SSE
"preview in timeline"	Show track summary
"Export button" / "导出"	Execute export workflow

Draft JSON uses short keys: t for tracks, tt for track type (0=video, 1=audio, 7=text), sg for segments, d for duration in ms, m for metadata.

Example timeline summary:

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

Error Codes

• 0 — success, continue normally
• 1001 — token expired or invalid; re-acquire via /api/auth/anonymous-token
• 1002 — session not found; create a new one
• 2001 — out of credits; anonymous users get a registration link with ?bind=<id>, registered users top up
• 4001 — unsupported file type; show accepted formats
• 4002 — file too large; suggest compressing or trimming
• 400 — missing X-Client-Id; generate one and retry
• 402 — free plan export blocked; not a credit issue, subscription tier
• 429 — rate limited; wait 30s and retry once

Tips and Tricks

The backend processes faster when you're specific. Instead of "make it look better", try "extend and auto-generate subtitles for the full video in English" — 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 → "extend and auto-generate subtitles for the full video in English" → 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.