Ai Free Subtitle Maker

Skip the learning curve of professional editing software. Describe what you want — automatically generate and add subtitles in English — and get captioned vi...

Security Scan

The skill's declared purpose (auto-generate subtitles via a remote API) is plausible and many requirements match that purpose, but there are internal inconsistencies and a few instructions that expand the skill's scope (probing install paths / local config) which merit caution before installing or granting credentials.

Purpose & Capability

The skill is described as a remote subtitle-generation front end and legitimately needs an API token for a backend service (NEMO_TOKEN). However the SKILL.md frontmatter includes a configPaths entry (~/.config/nemovideo/) and runtime instructions that detect install paths (~/.clawhub/, ~/.cursor/skills/) for attribution — the registry metadata shown to you listed no required config paths. This mismatch (declared none vs SKILL.md wanting config paths and path detection) is inconsistent and worth verifying.

Instruction Scope

Runtime instructions direct uploading user video/audio files to https://mega-api-prod.nemovideo.ai, creating/storing session tokens, streaming SSE, and detecting local install paths to set an X-Skill-Platform header. Reading install path or local config for attribution is outside the minimal scope of subtitle generation and touches user file-system information; that is scope creep and a privacy concern. The instructions also instruct the agent to obtain anonymous tokens automatically if NEMO_TOKEN is missing — this is operationally reasonable but should be transparent to users.

Install Mechanism

No install spec and no code files (instruction-only). Lowest-risk in terms of code being written to disk. There is no external download or package install in the spec.

Credentials

Only one environment variable (NEMO_TOKEN) is required, which is proportional for an API-based service. However SKILL.md references local config paths and install-path detection that would let the skill read user-specific filesystem locations; that access is not justified by the stated need for a single API token and should be clarified.

Persistence & Privilege

always:false and the skill does not request permanent system-wide privileges. It asks to store a session_id for the service (expected for API interactions) but does not request modification of other skills or global agent settings.

What to consider before installing

This skill mostly behaves like a normal API-driven subtitle generator, but verify a few things before enabling it: (1) Confirm you trust the backend domain (mega-api-prod.nemovideo.ai) and its privacy policy — your videos will be uploaded there. (2) Ask the publisher why the skill needs to detect install paths or read ~/.config/nemovideo/ (this leaks which client you use and some local path data). (3) Prefer setting a limited/replaceable API token (NEMO_TOKEN) and avoid using long-lived or broadly privileged credentials. (4) If you have sensitive video content, do not upload it until you confirm where and how files and tokens are stored and who can access them. (5) If anything about the headers, anonymous-token flow, or file retention is unclear, request clarification from the skill author — the metadata mismatch (registry vs SKILL.md) should be resolved before trusting the skill.

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:

• "add my video files"
• "export 1080p MP4"
• "automatically generate and add subtitles in"

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.

AI Free Subtitle Maker — Auto-Generate Subtitles for Videos

Send me your video files and describe the result you want. The AI subtitle generation runs on remote GPU nodes — nothing to install on your machine.

A quick example: upload a 3-minute YouTube tutorial video, type "automatically generate and add subtitles in English", 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 the fastest.

Matching Input to Actions

User prompts referencing ai free subtitle maker, 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.

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

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

Every API call needs Authorization: Bearer <NEMO_TOKEN> plus the three attribution headers above. If any header is missing, exports return 402.

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=<id> (get <id> 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

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.

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

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 "automatically generate and add subtitles in English" — 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.

Common Workflows

Quick edit: Upload → "automatically generate and add subtitles in English" → 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.