Free Subtitle

Skip the learning curve of professional editing software. Describe what you want — automatically generate and add subtitles to my video for free — and get ca...

Security Scan

The skill's behavior mostly matches its subtitle-generation purpose, but it will upload user videos and create/use cloud tokens on an external domain and its metadata inconsistently references a local config path — review privacy/token handling and the config-path mismatch before installing.

Purpose & Capability

Name/description (generate and burn-in subtitles) aligns with the required credential (NEMO_TOKEN) and the SKILL.md network calls to a video-processing backend. Requesting a service token to call a cloud API is expected for this functionality.

Instruction Scope

Runtime instructions will upload user video files (or URLs) and send them to https://mega-api-prod.nemovideo.ai for processing, and the agent may generate an anonymous token itself if NEMO_TOKEN is not present. Uploading potentially sensitive user files to a third-party backend is a privacy/security consideration the user should be aware of. The instructions do not request unrelated local files or unusual env vars, but they do instruct network calls that transmit user content and session tokens.

Install Mechanism

Instruction-only skill with no install spec or code files. No packages or downloads are performed by an installer, so there is minimal local install risk.

Credentials

The declared primary credential NEMO_TOKEN is appropriate for a cloud service. However the SKILL.md frontmatter metadata references a config path (~/.config/nemovideo/) that could imply reading/writing local configuration or stored tokens; the registry metadata shown earlier listed no required config paths — this mismatch is unexplained and increases the risk that local files or tokens could be accessed. The skill also documents automatically obtaining an anonymous token if none is present, which will cause outbound requests that create and use credentials on the remote service.

Persistence & Privilege

always:false and autonomous invocation allowed (the platform default). The skill does not request permanent system-wide privileges or claim to modify other skills' configs. It will keep session_id and token values for the session lifecycle (expected for a cloud API-driven skill).

What to consider before installing

This skill will send any uploaded video files to mega-api-prod.nemovideo.ai for cloud processing and will use or obtain a NEMO_TOKEN (anonymous token if none provided). Before installing, consider: 1) privacy: are you comfortable uploading the specific videos (and any sensitive content) to that external service? 2) token handling: the skill may create and use tokens and may reference a local config path (~/.config/nemovideo/) — verify whether it will read/write local config or store tokens locally. 3) trust the domain/service: confirm the service's reputation, terms, and retention policy for uploaded media. If you need stronger guarantees, avoid supplying sensitive videos, create an account with the provider and use scoped credentials, or decline installation. The SKILL.md frontmatter also conflicts with the registry manifest about required config paths — ask the publisher to clarify that mismatch before trusting the skill.

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"
• "automatically generate and add subtitles to"

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.

Free Subtitle — Generate and Burn In Captions

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 automatically generate and add subtitles to my video for free, 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 generate subtitles the fastest.

Matching Input to Actions

User prompts referencing free subtitle, 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	free-subtitle
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 → "automatically generate and add subtitles to my video for free" → 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 "automatically generate and add subtitles to my video for free" — 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.