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tk8544-b

Add Subtitle To Video Free

by tk8544-b · GitHub ↗ · v1.0.0 · MIT-0
cross-platform ⚠ suspicious
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Install in OpenClaw
/install add-subtitle-to-video-free
Description
Turn a 3-minute YouTube tutorial recording into 1080p captioned video files just by typing what you need. Whether it's adding subtitles to YouTube or social...
README (SKILL.md)

Getting Started

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

Try saying:

  • "add a 3-minute YouTube tutorial recording into a 1080p MP4"
  • "add English subtitles automatically and sync them to my speech"
  • "adding subtitles to YouTube or social media videos for YouTubers, content creators, students"

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: \x3Cuuid>. 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.

Add Subtitle to Video Free — 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 recording, ask for add English subtitles automatically and sync them to my speech, 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 generate subtitles significantly faster.

Matching Input to Actions

User prompts referencing add subtitle to video free, 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.

Skill attribution — read from this file's YAML frontmatter at runtime:

  • X-Skill-Source: add-subtitle-to-video-free
  • X-Skill-Version: from frontmatter version
  • X-Skill-Platform: detect from install path (~/.clawhub/clawhub, ~/.cursor/skills/cursor, else unknown)

Include Authorization: Bearer \x3CNEMO_TOKEN> and all attribution headers on every request — omitting them triggers a 402 on export.

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)

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.

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

Common Workflows

Quick edit: Upload → "add English subtitles automatically and sync them to my speech" → 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 English subtitles automatically and sync them to my speech" — 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.

Usage Guidance
This skill will upload any video files you drop into the chat to a third-party service (mega-api-prod.nemovideo.ai) for subtitle generation and rendering — make sure you trust that service and its privacy terms before use. The skill requires an API token (NEMO_TOKEN); if you don't provide one it will request an anonymous token from the service and use that token (100 credits, 7‑day expiry). The SKILL.md also instructs the agent to detect its install path (e.g., ~/.clawhub/ or ~/.cursor/skills/) to set an X-Skill-Platform header and to persist session IDs — this requires the agent to read some files/paths on disk, which may expose environment details. Before installing, consider: 1) Are you comfortable with uploading your videos to the listed domain? 2) Do you trust issuing a bearer token to that service (or letting the skill obtain an anonymous one)? 3) Do you want the agent to read install paths and persist session tokens? If you need higher assurance, ask the skill author for an explicit privacy/security statement, the service's official domain and docs, and clarification why configPaths are present in the frontmatter but not declared in the registry metadata.
Capability Analysis
Type: OpenClaw Skill Name: add-subtitle-to-video-free Version: 1.0.0 The skill is a legitimate integration for an AI video processing service hosted at nemovideo.ai. It provides detailed instructions for the agent to manage API sessions, handle file uploads, and process video subtitles via Server-Sent Events (SSE). The requested permissions (NEMO_TOKEN and ~/.config/nemovideo/) are appropriate for its stated purpose, and the instructions include security-conscious directives such as not printing raw tokens to the user.
Capability Assessment
Purpose & Capability
The declared runtime behavior (calling mega-api-prod.nemovideo.ai to upload videos, generate subtitles, and export MP4s) matches the skill's stated purpose. However the SKILL.md frontmatter includes configPaths (~/.config/nemovideo/) while the registry metadata lists no required config paths — this mismatch is an incoherence. The need for NEMO_TOKEN is expected for an external API, but the extra frontmatter config path is unexplained.
Instruction Scope
Instructions tell the agent to upload user video files, create anonymous tokens if NEMO_TOKEN is absent, persist session_id, poll rendering endpoints, and include attribution headers. Notably the skill instructs detecting the agent's install path to populate X-Skill-Platform (reading ~/.clawhub/ or ~/.cursor/skills/), which requires filesystem access beyond simple API calls. Uploading user files to a third-party service is expected for this feature, but the install-path probe and implicit token persistence broaden scope and should be explicit to the user.
Install Mechanism
Instruction-only skill with no install spec or code files — lowest install risk. Nothing is downloaded or written by an installer step in the package itself.
Credentials
The skill requests a single credential: NEMO_TOKEN, which is proportionate for an API integration. The SKILL.md also documents creating an anonymous token via an API call if NEMO_TOKEN is absent (100 credits, 7-day expiry). The earlier-noted frontmatter configPaths increase the surface area (implies reading ~/.config/nemovideo/) without justification in the registry metadata.
Persistence & Privilege
always:false (default) — no forced permanent presence. The instructions ask to 'save session_id' and to reuse or set NEMO_TOKEN when available; this implies the agent may persist these values for subsequent calls. That is reasonable for session-based APIs but users should know tokens/sessions may be stored by the agent runtime.
How to Use
  1. Make sure OpenClaw is installed (local or Docker)
  2. Run the install command in chat: /install add-subtitle-to-video-free
  3. After installation, invoke the skill by name or use /add-subtitle-to-video-free
  4. Provide required inputs per the skill's parameter spec and get structured output
Version History
v1.0.0
Initial release — easily add AI-generated, burned-in subtitles to your videos with no manual editing. - Upload a video and describe your desired result; automatic subtitle generation and syncing. - Supports quick workflows: 30-60 seconds from upload to downloadable 1080p MP4. - No local software needed; everything runs on cloud GPUs. - Handles video uploads, subtitles, aspect ratio, and format exports via chat commands. - Free usage includes 100 credits (7 days) with anonymous sign-in—no registration needed.
Metadata
Slug add-subtitle-to-video-free
Version 1.0.0
License MIT-0
All-time Installs 0
Active Installs 0
Total Versions 1
Frequently Asked Questions

What is Add Subtitle To Video Free?

Turn a 3-minute YouTube tutorial recording into 1080p captioned video files just by typing what you need. Whether it's adding subtitles to YouTube or social... It is an AI Agent Skill for Claude Code / OpenClaw, with 78 downloads so far.

How do I install Add Subtitle To Video Free?

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

Is Add Subtitle To Video Free free?

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

Which platforms does Add Subtitle To Video Free support?

Add Subtitle To Video Free is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).

Who created Add Subtitle To Video Free?

It is built and maintained by tk8544-b (@tk8544-b); the current version is v1.0.0.

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