Best Subtitle Generator

Skip the learning curve of professional editing software. Describe what you want — generate subtitles in English and Spanish and burn them into the video — a...

Security Scan

The skill's runtime instructions generally match a cloud subtitle service, but there are inconsistent declarations about required credentials/config paths and it will upload your video files to an external API — review privacy and the metadata mismatches before installing.

Purpose & Capability

The skill's stated purpose (generate and burn-in subtitles) aligns with the runtime instructions (upload video, start a session, render/export). However the registry metadata and SKILL.md disagree: the top-level registry data lists no required config paths while the SKILL.md frontmatter declares a config path (~/.config/nemovideo/). That mismatch is unexplained and should be clarified.

Instruction Scope

SKILL.md instructs the agent to obtain/use a NEMO_TOKEN (or create an anonymous token), create sessions, upload video files (up to 500MB), stream SSE responses, poll render status, and download results. These actions are within the expected scope for a cloud subtitle/rendering service. The doc also mentions deriving headers from install-path detection (e.g., reading ~/.clawhub/), which implies filesystem probing to determine platform metadata — this is not strictly required for subtitle generation and should be noted.

Install Mechanism

This is an instruction-only skill with no install spec and no code files, so nothing is written to disk by an installer. That reduces install-time risk.

Credentials

The registry declares NEMO_TOKEN as a required primary credential which is appropriate for an API-backed service. But SKILL.md explicitly provides a fallback path that generates an anonymous token if NEMO_TOKEN is not set. The mismatch between a declared required env var and the documented anonymous-token flow is inconsistent. SKILL.md also claims a config path (~/.config/nemovideo/) for saving session/token state — this wasn't declared in the top-level 'Required config paths' field, another inconsistency. Aside from NEMO_TOKEN and the optional config path, no unrelated credentials are requested.

Persistence & Privilege

The skill is not always-enabled and uses standard autonomous invocation. It will create and persist session state/tokens (SKILL.md says to 'save session_id' and mentions ~/.config/nemovideo/), which is expected for a cloud session-based service but means tokens or session identifiers may be stored on disk. It does not request elevated system-wide privileges or modify other skills.

Scan Findings in Context

[no_code_files_to_scan] expected: The package is instruction-only (SKILL.md only). The regex scanner had no code files to analyze — this is expected for an instruction-only integration but means runtime behavior is governed solely by the prose in SKILL.md.

What to consider before installing

This skill appears to be a cloud-based subtitle service and will upload user video files to mega-api-prod.nemovideo.ai for processing — that's expected for the stated purpose but has privacy implications. Before installing: (1) Confirm you trust the nemovideo.ai domain and its privacy/retention policies (sensitive videos will leave your device). (2) Note metadata inconsistencies: the registry marks NEMO_TOKEN as required but the instructions say an anonymous token can be created; SKILL.md also references a config path (~/.config/nemovideo/) that the registry didn't list. Ask the publisher to clarify how tokens and session data are stored and whether anything is written to disk. (3) If you prefer tighter control, supply your own NEMO_TOKEN (if you have an account) rather than relying on anonymous tokens, and avoid uploading sensitive content. (4) If you need higher assurance, request the publisher's homepage/owner identity and examine network traffic or run in a restricted environment before using with private material.

Getting Started

Ready when you are. Drop your video files here or describe what you want to make.

Try saying:

• "add a 3-minute YouTube tutorial video into a 1080p MP4"
• "generate subtitles in English and Spanish and burn them into the video"
• "adding accurate subtitles to videos automatically for YouTubers, content creators, marketers"

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.

Best Subtitle Generator — Auto-Generate and Burn In Subtitles

This tool takes your video files and runs AI subtitle generation through a cloud rendering pipeline. You upload, describe what you want, and download the result.

Say you have a 3-minute YouTube tutorial video and want to generate subtitles in English and Spanish and burn them into the video — the backend processes it in about 30-60 seconds and hands you a 1080p MP4.

Tip: shorter clips under 5 minutes generate subtitles significantly faster.

Matching Input to Actions

User prompts referencing best subtitle generator, 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.

Base URL: https://mega-api-prod.nemovideo.ai

Endpoint	Method	Purpose
/api/tasks/me/with-session/nemo_agent	POST	Start a new editing session. Body: {"task_name":"project","language":"<lang>"}. Returns session_id.
/run_sse	POST	Send a user message. Body includes app_name, session_id, new_message. Stream response with Accept: text/event-stream. Timeout: 15 min.
/api/upload-video/nemo_agent/me/<sid>	POST	Upload a file (multipart) or URL.
/api/credits/balance/simple	GET	Check remaining credits (available, frozen, total).
/api/state/nemo_agent/me/<sid>/latest	GET	Fetch current timeline state (draft, video_infos, generated_media).
/api/render/proxy/lambda	POST	Start export. Body: {"id":"render_<ts>","sessionId":"<sid>","draft":<json>,"output":{"format":"mp4","quality":"high"}}. Poll status every 30s.

Accepted file types: mp4, mov, avi, webm, mkv, jpg, png, gif, webp, mp3, wav, m4a, aac.

Headers are derived from this file's YAML frontmatter. X-Skill-Source is best-subtitle-generator, 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).

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

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

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)

Tips and Tricks

The backend processes faster when you're specific. Instead of "make it look better", try "generate subtitles in English and Spanish and burn them into the 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 devices.

Common Workflows

Quick edit: Upload → "generate subtitles in English and Spanish and burn them into the 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.