Subtitle Generator For Video

Skip the learning curve of professional editing software. Describe what you want — add subtitles in English and Spanish to my video — and get captioned video...

Security Scan

The skill's instructions mostly match a cloud subtitle service, but there are configuration/metadata inconsistencies and a small scope creep risk (token creation/storage and a referenced local config path) that should be clarified before installing.

Purpose & Capability

The skill's name and description align with an online subtitle/encoding service and the single required credential (NEMO_TOKEN) is consistent with calling a third‑party API. However, the SKILL.md frontmatter lists a local config path (~/.config/nemovideo/) while the registry metadata above says 'Required config paths: none' — this mismatch is unexplained and could indicate the skill expects to read or store local credentials/config even though the registry didn't declare it.

Instruction Scope

Instructions tell the agent how to obtain an anonymous token, create and store session IDs, upload local files (multipart -F "files=@/path"), open SSE streams, poll render status, and include attribution headers. All of those are reasonable for a cloud video processing skill, but they include steps that read/upload user files and may store/use tokens locally. The guidance to 'not display raw API responses or token values' shows awareness of secrets, but the SKILL.md does not clearly define where/how tokens/session IDs are stored and whether any local config is read/written (the referenced config path increases that uncertainty).

Install Mechanism

There is no install spec and no code files — the skill is instruction-only, which minimizes install risk (nothing is downloaded or written by an installer).

Credentials

Only one environment variable (NEMO_TOKEN) is declared as required and is appropriate for a third‑party subtitle service. The SKILL.md also documents a fallback flow to obtain an anonymous token automatically; that is proportionate but implies the skill will generate, store, and reuse credentials. The implicit expectation to access or populate ~/.config/nemovideo/ (per frontmatter) is not justified by the registry metadata and should be clarified.

Persistence & Privilege

The skill is not always-enabled and doesn't request elevated or platform-wide privileges. Autonomous invocation is allowed (normal default). The only persistence concern is potential local storage of short‑lived tokens/session IDs — the SKILL.md does not explain storage location or retention policy.

What to consider before installing

This skill appears to implement a cloud subtitle/upload workflow and only needs one token (NEMO_TOKEN), which is reasonable. Before installing, ask or confirm: (1) whether the skill will read or write files under ~/.config/nemovideo/ (the frontmatter references that path but the registry did not), (2) how and where the anonymous token (if auto‑created) and session IDs are stored and how long they're retained, and (3) that uploaded videos will be sent to https://mega-api-prod.nemovideo.ai (verify you trust that service). If you don't want tokens stored locally, decline or remove the skill or ensure the agent only accepts a token provided at runtime. Because of the config-path metadata mismatch and implicit local token storage, treat this as suspicious until the developer clarifies storage behavior and the exact need for the config path.

Getting Started

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

Try saying:

• "add a 3-minute tutorial video in MP4 format into a 1080p MP4"
• "add subtitles in English and Spanish to my video"
• "adding subtitles to YouTube videos for YouTubers and content creators"

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 Generator for Video — Generate and Embed Video Subtitles

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

Here's a typical use: you send a a 3-minute tutorial video in MP4 format, ask for add subtitles in English and Spanish to my video, 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 5 minutes process significantly faster.

Matching Input to Actions

User prompts referencing subtitle generator for video, 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.

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

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

Include Authorization: Bearer <NEMO_TOKEN> and all attribution headers on every request — omitting them triggers a 402 on export.

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.

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.

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

Common Workflows

Quick edit: Upload → "add subtitles in English and Spanish to 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 "add subtitles in English and Spanish to 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.