Subtitle Video Online

Turn a 3-minute tutorial video in MP4 into 1080p captioned video files just by typing what you need. Whether it's adding subtitles to videos online without s...

Security Scan

The skill is an instruction-only client for a third‑party subtitle/rendering service (it will upload videos and manage a service token), but there are inconsistencies in its declared requirements and ambiguity about where tokens/config are stored and who runs the backend — review before installing or uploading sensitive content.

Purpose & Capability

The skill's name/description match the actions in SKILL.md: it uploads videos, requests subtitles, and exports rendered MP4s from a remote service. The declared primary env var (NEMO_TOKEN) is appropriate for that purpose. However, registry metadata says no required config paths while the SKILL.md frontmatter includes a config path (~/.config/nemovideo/) — that mismatch is unexpected and should be clarified.

Instruction Scope

Instructions will upload user video files and interact with an external API (mega-api-prod.nemovideo.ai). The skill instructs the agent to generate an anonymous token if NEMO_TOKEN is not present and to 'store' the token and session_id for subsequent requests; it is unclear where/how tokens or session state should be persisted (environment, agent memory, or disk). The SKILL.md also requires reading/writing a config path in frontmatter — reading or writing user config files is scope creep for a simple subtitle helper and is not documented in the registry metadata.

Install Mechanism

This is instruction-only with no install spec or code files, so nothing is written to disk by an installer. That minimizes install-time risk but also means there is no code to audit beyond the instructions.

Credentials

Only a single credential (NEMO_TOKEN) is declared, which is proportionate to a third‑party API client. But SKILL.md describes obtaining an anonymous token automatically and storing it, and frontmatter mentions a config path — these behaviors imply the skill may read/write credentials or config in the user's environment without explicit consent. Also the service will receive full video files, so the privacy implications are material.

Persistence & Privilege

The skill is not always-enabled and doesn't request elevated platform privileges. However, it instructs the agent to persist the anonymous token and session_id and references a per-user config directory (~/.config/nemovideo/) — that implies persistent storage of credentials/state which should be documented and consented to. Autonomous invocation is allowed (platform default) which increases the impact if persistence is misused.

What to consider before installing

This skill will upload your videos to a third‑party service and either use an existing NEMO_TOKEN or create and store an anonymous token for you. Before installing: 1) Confirm the service domain (mega-api-prod.nemovideo.ai) and owner — there's no homepage or source link in the registry. 2) Decide whether you want your videos sent to an external service (don't upload sensitive content). 3) Ask the developer where tokens/session state are stored (env var vs disk) and whether the config path (~/.config/nemovideo/) will be read/written. 4) Prefer supplying your own service token rather than allowing automatic anonymous token creation if you need control over retention/consent. 5) If you proceed, monitor what the skill stores (agent state or config files) and revoke any anonymous token/credits when done.

Getting Started

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

Try saying:

• "add my video files"
• "export 1080p MP4"
• "add subtitles in English and French"

First-Time Connection

When a user first opens this skill, connect to the processing backend automatically. Briefly let them know (e.g. "Setting up...").

Authentication: Check if NEMO_TOKEN is set in the environment. If it is, skip to step 2.

1. Obtain a free token: Generate a random UUID as client identifier. POST to https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token with header X-Client-Id set to that UUID. The response data.token is your NEMO_TOKEN — 100 free credits, valid 7 days.
2. Create a session: POST to https://mega-api-prod.nemovideo.ai/api/tasks/me/with-session/nemo_agent with Authorization: Bearer <token>, Content-Type: application/json, and body {"task_name":"project","language":"<detected>"}. Store the returned session_id for all subsequent requests.

Keep setup communication brief. Don't display raw API responses or token values to the user.

Subtitle Video Online — Add Subtitles to Videos Online

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 tutorial video in MP4, type "add subtitles in English and French automatically", 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 video online, 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 calls go to https://mega-api-prod.nemovideo.ai. The main endpoints:

1. Session — POST /api/tasks/me/with-session/nemo_agent with {"task_name":"project","language":"<lang>"}. Gives you a session_id.
2. Chat (SSE) — POST /run_sse with session_id and your message in new_message.parts[0].text. Set Accept: text/event-stream. Up to 15 min.
3. Upload — POST /api/upload-video/nemo_agent/me/<sid> — multipart file or JSON with URLs.
4. Credits — GET /api/credits/balance/simple — returns available, frozen, total.
5. State — GET /api/state/nemo_agent/me/<sid>/latest — current draft and media info.
6. Export — POST /api/render/proxy/lambda with render ID and draft JSON. Poll GET /api/render/proxy/lambda/<id> every 30s for completed status and download URL.

Formats: 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	subtitle-video-online
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.

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)

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

Reading the SSE Stream

Text events go straight to the user (after GUI translation). Tool calls stay internal. Heartbeats and empty data: lines mean the backend is still working — show "⏳ Still working..." every 2 minutes.

About 30% of edit operations close the stream without any text. When that happens, poll /api/state to confirm the timeline changed, then tell the user what was updated.

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 "add subtitles in English and French automatically" — 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 → "add subtitles in English and French automatically" → 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.