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whitejohnk-26

Best Video Subtitle Generator

by whitejohnk-26 · GitHub ↗ · v1.0.0 · MIT-0
cross-platform ✓ Security Clean
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Install in OpenClaw
/install best-video-subtitle-generator
Description
Turn a 10-minute YouTube tutorial recording into 1080p captioned video files just by typing what you need. Whether it's adding subtitles to YouTube and socia...
README (SKILL.md)

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:

  • "generate my video files"
  • "export 1080p MP4"
  • "add captions in English and Spanish"

Getting Connected

Before handling any user request, establish a connection to the backend API. Show a brief status like "Connecting...".

If NEMO_TOKEN is in the environment, use it directly and create a session. Otherwise, acquire a free starter token:

  • Generate a UUID as client identifier
  • POST to https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token with the X-Client-Id header
  • The response includes a token with 100 free credits valid for 7 days — use it as NEMO_TOKEN

Then create a session by POSTing to https://mega-api-prod.nemovideo.ai/api/tasks/me/with-session/nemo_agent with Bearer authorization and body {"task_name":"project","language":"en"}. The session_id in the response is needed for all following requests.

Tell the user you're ready. Keep the technical details out of the chat.

Best Video Subtitle Generator — Generate and Embed Video Captions

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 10-minute YouTube tutorial recording and want to add captions in English and Spanish with auto-sync — 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 video 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.

All calls go to https://mega-api-prod.nemovideo.ai. The main endpoints:

  1. SessionPOST /api/tasks/me/with-session/nemo_agent with {"task_name":"project","language":"\x3Clang>"}. 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. UploadPOST /api/upload-video/nemo_agent/me/\x3Csid> — multipart file or JSON with URLs.
  4. CreditsGET /api/credits/balance/simple — returns available, frozen, total.
  5. StateGET /api/state/nemo_agent/me/\x3Csid>/latest — current draft and media info.
  6. ExportPOST /api/render/proxy/lambda with render ID and draft JSON. Poll GET /api/render/proxy/lambda/\x3Cid> every 30s for completed status and download URL.

Formats: 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-video-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).

All requests must include: Authorization: Bearer \x3CNEMO_TOKEN>, X-Skill-Source, X-Skill-Version, X-Skill-Platform. Missing attribution headers will cause export to fail with 402.

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)

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

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 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=\x3Cid> (get \x3Cid> 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

Tips and Tricks

The backend processes faster when you're specific. Instead of "make it look better", try "add captions in English and Spanish with auto-sync" — 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 all platforms.

Common Workflows

Quick edit: Upload → "add captions in English and Spanish with auto-sync" → 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.

Usage Guidance
This skill appears internally consistent for generating and embedding subtitles via the nemo video backend, but it will upload your video files to an external service. Before using it: (1) confirm you trust the nemo backend domain and its privacy/data-retention policy, (2) only set NEMO_TOKEN you control (do not reuse general-purpose secrets), (3) avoid sending sensitive or private videos unless you know how they will be stored/used, and (4) be aware the skill may automatically obtain an anonymous token if no NEMO_TOKEN is present and will try to detect an install path to populate an attribution header. If you need higher assurance, ask the publisher for a homepage/privacy policy or an auditable implementation rather than the instruction-only skill.
Capability Analysis
Type: OpenClaw Skill Name: best-video-subtitle-generator Version: 1.0.0 The skill is a functional wrapper for a video subtitle generation service hosted at nemovideo.ai. It manages API sessions, handles file uploads, and polls for video rendering status. While it requires an API token (NEMO_TOKEN) and performs platform detection for telemetry (checking install paths like ~/.clawhub/), its behavior is transparently documented and strictly aligned with its stated purpose of processing video files. No evidence of data exfiltration or unauthorized execution was found.
Capability Assessment
Purpose & Capability
Name/description (video subtitle + rendering) match the runtime instructions: all API calls, uploads, session creation, and exports are to the nemo video backend. The single required env var (NEMO_TOKEN) is consistent with the claimed cloud service.
Instruction Scope
Instructions describe uploading user video content, creating sessions, SSE chat, polling exports, and optionally obtaining an anonymous token from the service if NEMO_TOKEN is absent. This stays within the stated purpose. Two minor scope items to note: (1) it instructs the agent to detect install path to set an X-Skill-Platform header (reading that path is out-of-band metadata access), and (2) it tells the agent to keep technical details out of the chat (i.e., perform API activity quietly). Neither is obviously malicious but they reduce transparency.
Install Mechanism
No install spec and no code files — instruction-only. This minimizes disk-write/execute risk. The skill relies entirely on runtime HTTP calls to the external API.
Credentials
Only a single credential (NEMO_TOKEN) is declared and used for the API; if absent the skill requests an anonymous token directly from the service. No unrelated secrets or broad system paths are requested.
Persistence & Privilege
always:false and no instructions to modify other skills or system-wide config. The skill asks the agent to read the install path for a header, but it does not request permanent privileges or forced inclusion.
How to Use
  1. Make sure OpenClaw is installed (local or Docker)
  2. Run the install command in chat: /install best-video-subtitle-generator
  3. After installation, invoke the skill by name or use /best-video-subtitle-generator
  4. Provide required inputs per the skill's parameter spec and get structured output
Version History
v1.0.0
Initial release — Best Video Subtitle Generator skill. - Enables users to generate and embed AI-powered video subtitles and captions via a simple upload and describe workflow. - Supports rapid subtitle generation (30–60 seconds) for short video clips, with easy export to formats like 1080p MP4. - Automatically manages API connection, authentication, and session handling, choosing the correct flow for registered or anonymous users. - Integrates status and error reporting, including credit status, supported formats, and clear error messages for failed actions. - Provides direct mapping between user prompts and actions: upload, export, balance check, and track summary. - Includes robust error handling for common issues like token expiry, no credits, or export access limitations.
Metadata
Slug best-video-subtitle-generator
Version 1.0.0
License MIT-0
All-time Installs 0
Active Installs 0
Total Versions 1
Frequently Asked Questions

What is Best Video Subtitle Generator?

Turn a 10-minute YouTube tutorial recording into 1080p captioned video files just by typing what you need. Whether it's adding subtitles to YouTube and socia... It is an AI Agent Skill for Claude Code / OpenClaw, with 100 downloads so far.

How do I install Best Video Subtitle Generator?

Run "/install best-video-subtitle-generator" in the OpenClaw or Claude Code chat to install it in one step — no extra setup required.

Is Best Video Subtitle Generator free?

Yes, Best Video Subtitle Generator is completely free, licensed under MIT-0. You can download, install and use it at no cost.

Which platforms does Best Video Subtitle Generator support?

Best Video Subtitle Generator is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).

Who created Best Video Subtitle Generator?

It is built and maintained by whitejohnk-26 (@whitejohnk-26); the current version is v1.0.0.

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