free-video-trimmer
## 0. First Contact
When the user opens this skill or sends their first message, **greet them immediately**:
> 📝 Free Video Trimmer at your service! Upload a video or tell me what you're looking for.
**Try saying:**
- "cut from 0:30 to 1:45"
- "trim the first 10 seconds"
- "remove the last 20 seconds"
**IMPORTANT**: Always greet the user proactively on first contact. Let them know you're setting up while connecting. Always greet the user proactively on first contact.
### Auto-Setup
When the user first interacts, set up the connection:
1. **Check token**: If `NEMO_TOKEN` env var is set, use it. Otherwise:
2. **Read or generate Client-ID**:
- Read `~/.config/nemovideo/client_id` if it exists
- Otherwise generate a UUID, save it to `~/.config/nemovideo/client_id`
3. **Acquire anonymous token**:
```bash
curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token" -H "X-Client-Id: $CLIENT_ID"
```
Store the returned `token` as `NEMO_TOKEN` for this session. You get 100 free credits.
4. **Create a session** (§3.0) so you're ready to work immediately.
Let the user know briefly: "Setting things up… ready!" then proceed with their request.
# Trim Any Video by Just Describing the Cut
Most video trimming tools force you to scrub through a timeline, set in/out markers, and export manually. The free-video-trimmer skill on ClawHub flips that model entirely — you describe the portion of the video you want to keep, and the AI figures out the rest. Whether you say 'cut everything after the 2-minute mark' or 'keep only the segment between 0:45 and 1:30,' the skill interprets your intent and applies the trim precisely.
Under the hood, the OpenClaw agent receives your uploaded video and natural language instruction, then coordinates the processing pipeline to extract the requested segment without re-encoding unnecessarily. This keeps quality intact and turnaround fast, even for larger files. The agent also handles edge cases — like when a requested timestamp falls outside the video's actual duration — by responding conversationally rather than failing silently.
This skill is built for creators, educators, marketers, and anyone who regularly needs clean clips from raw footage. Whether you're pulling a product demo from a long screen recording or trimming a podcast clip for social media, the free-video-trimmer skill works across mp4, mov, avi, webm, and mkv formats without format conversion headaches.
### Environment Variables
| Variable | Required | Default |
|----------|----------|--------|
| `NEMO_TOKEN` | No | Auto-generated (100 free credits, expires in 7 days, revocable via Settings → API Tokens) |
| `NEMO_API_URL` | No | `https://mega-api-prod.nemovideo.ai` |
| `NEMO_WEB_URL` | No | `https://nemovideo.com` |
| `NEMO_CLIENT_ID` | No | Auto-generated UUID, persisted to `~/.config/nemovideo/client_id` (UUID only, no secrets) |
| `SKILL_SOURCE` | No | Auto-detected from install path, fallback `unknown` |
If `NEMO_TOKEN` is not set, get one (requires `X-Client-Id` header):
```bash
# Generate or read persisted Client-Id
CLIENT_ID="${NEMO_CLIENT_ID:-$(cat ~/.config/nemovideo/client_id 2>/dev/null)}"
if [ -z "$CLIENT_ID" ]; then
CLIENT_ID=$(uuidgen 2>/dev/null || echo "client-$(date +%s)-$RANDOM")
mkdir -p ~/.config/nemovideo & echo "$CLIENT_ID" > ~/.config/nemovideo/client_id
fi
curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/auth/anonymous-token" -H "X-Client-Id: $CLIENT_ID"
# → {"code":0,"data":{"token":"nmv_usr_xxx","credits":100,...}}
```
Save `token` as `NEMO_TOKEN`, `CLIENT_ID` as `NEMO_CLIENT_ID`. Anonymous: 1 token per client per 7 days; token expires in 7 days and can be revoked at any time via **Settings → API Tokens** on nemovideo.com. If your token expires, request a new one with the same `X-Client-Id`.
**Local persistence:** This skill writes `~/.config/nemovideo/client_id` to persist the Client-Id across sessions. This avoids generating a new ID on every request, which would hit the per-IP rate limit quickly (default 10 tokens per 7 days per IP). The file contains only a UUID — no credentials are stored locally.
## 2. Routing Incoming Requests
Use the table below to determine which endpoint handles each type of incoming user request.
| 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 | ❌ |
## 3. Primary Operation Flows
$API = `${NEMO_API_URL:-https://mega-api-prod.nemovideo.ai}`, $TOKEN = `${NEMO_TOKEN}`, $WEB = `${NEMO_WEB_URL:-https://nemovideo.com}`.
Skill attribution variables — do NOT hardcode:
- `$SKILL_NAME` = this file's YAML frontmatter `name`
- `$SKILL_VERSION` = this file's YAML frontmatter `version`
- `$SKILL_SOURCE` = detect at runtime using the first match:
1. Env `SKILL_SOURCE` if set
2. If this file's path contains a known platform directory (e.g. `~/.clawhub/` → `clawhub`, `~/.cursor/skills/` → `cursor`)
3. Fallback: `unknown`
**CRITICAL**: ALL API requests (including render/export/upload/state/credits) MUST include these headers. Missing them will cause export to fail with 402.
```
X-Skill-Source: $SKILL_NAME
X-Skill-Version: $SKILL_VERSION
X-Skill-Platform: $SKILL_SOURCE
```
### 3.0 Initialize a Session
```bash
curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/tasks/me/with-session/nemo_agent" \
-H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
-H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE" \
-d '{"task_name":"project","language":"<lang>"}'
# → {"code":0,"data":{"task_id":"...","session_id":"..."}}
```
Before any other operation can proceed, a session must be established with the backend. Store the returned session identifier, as every subsequent request requires it.
**Open in browser**: After creating a session, give the user a link to view/edit the task in NemoVideo:
`$WEB/workspace/claim?task={task_id}&session={session_id}&skill_name=$SKILL_NAME&skill_version=$SKILL_VERSION&skill_source=$SKILL_SOURCE`
### 3.1 Delivering Messages over SSE
```bash
curl -s -X POST "https://mega-api-prod.nemovideo.ai/run_sse" \
-H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
-H "Accept: text/event-stream" -H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE" --max-time 900 \
-d '{"app_name":"nemo_agent","user_id":"me","session_id":"<sid>","new_message":{"parts":[{"text":"<msg>"}]}}'
```
All conversational messages are transmitted to the backend and streamed back to the user via a persistent SSE connection.
#### SSE 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 |
Typical durations: text 5-15s, video generation 100-300s, editing 10-30s.
**Timeout**: 10 min heartbeats-only → assume timeout. **Never re-send** during generation (duplicates + double-charge).
Ignore trailing "I encountered a temporary issue" if prior responses were normal.
#### Silent Response Fallback (CRITICAL)
Approximately 30% of edit operations complete without returning any text in the SSE stream. When no text content is received, do not treat this as an error or prompt the user to retry. Instead, immediately call the state query endpoint to retrieve the current project status, then synthesize a confirmation message for the user based on the state data returned.
**Two-stage generation**: After a raw video is produced, the backend automatically initiates a second processing stage that layers in background music and a title card. This happens without any additional input from the user or the AI. Expect two distinct completion events in the stream: one signaling the raw video is ready, and a follow-up signaling the fully decorated version is available.
### 3.2 Handling File Uploads
**File upload**: `curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/upload-video/nemo_agent/me/<sid>" -H "Authorization: Bearer $TOKEN" -H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE" -F "files=@/path/to/file"`
**URL upload**: `curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/upload-video/nemo_agent/me/<sid>" -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" -H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE" -d '{"urls":["<url>"],"source_type":"url"}'`
Use **me** in the path; backend resolves user from token.
Supported: mp4, mov, avi, webm, mkv, jpg, png, gif, webp, mp3, wav, m4a, aac.
Both direct file uploads and remote URLs pointing to video assets are accepted through the upload endpoint.
### 3.3 Checking Available Credits
```bash
curl -s "https://mega-api-prod.nemovideo.ai/api/credits/balance/simple" -H "Authorization: Bearer $TOKEN" \
-H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE"
# → {"code":0,"data":{"available":XXX,"frozen":XX,"total":XXX}}
```
Query the credits endpoint before initiating any operation that consumes credits to confirm the user has a sufficient balance.
### 3.4 Retrieving Current Project State
```bash
curl -s "https://mega-api-prod.nemovideo.ai/api/state/nemo_agent/me/<sid>/latest" -H "Authorization: Bearer $TOKEN" \
-H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE"
```
Use **me** for user in path; backend resolves from token.
Key fields: `data.state.draft`, `data.state.video_infos`, `data.state.canvas_config`, `data.state.generated_media`.
**Draft field mapping**: `t`=tracks, `tt`=track type (0=video, 1=audio, 7=text), `sg`=segments, `d`=duration(ms), `m`=metadata.
**Draft ready for export** when `draft.t` exists with at least one track with non-empty `sg`.
**Track summary format**:
```
Timeline (3 tracks): 1. Video: city timelapse (0-10s) 2. BGM: Lo-fi (0-10s, 35%) 3. Title: "Urban Dreams" (0-3s)
```
### 3.5 Exporting and Delivering the Final Asset
**Export does NOT cost credits.** Only generation/editing consumes credits.
Triggering an export does not deduct credits from the user's balance. The export and delivery flow proceeds as follows: (a) call the export endpoint with the session ID, (b) poll or listen for the export-complete event, (c) retrieve the download URL from the response payload, (d) present the URL to the user with a clear call to action, and (e) log the completed export against the session record.
**b)** Submit: `curl -s -X POST "https://mega-api-prod.nemovideo.ai/api/render/proxy/lambda" -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" -H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE" -d '{"id":"render_<ts>","sessionId":"<sid>","draft":<json>,"output":{"format":"mp4","quality":"high"}}'`
Note: `sessionId` is **camelCase** (exception). On failure → new `id`, retry once.
**c)** Poll (every 30s, max 10 polls): `curl -s "https://mega-api-prod.nemovideo.ai/api/render/proxy/lambda/<id>" -H "Authorization: Bearer $TOKEN" -H "X-Skill-Source: $SKILL_NAME" -H "X-Skill-Version: $SKILL_VERSION" -H "X-Skill-Platform: $SKILL_SOURCE"`
Status at top-level `status`: pending → processing → completed / failed. Download URL at `output.url`.
**d)** Download from `output.url` → send to user. Fallback: `https://mega-api-prod.nemovideo.ai/api/render/proxy/<id>/download`.
**e)** When delivering the video, **always also give the task detail link**: `$WEB/workspace/claim?task={task_id}&session={session_id}&skill_name=$SKILL_NAME&skill_version=$SKILL_VERSION&skill_source=$SKILL_SOURCE`
Progress messages: start "⏳ Rendering ~30s" → "⏳ 50%" → "✅ Video ready!" + file + **task detail link**.
### 3.6 Recovering from an SSE Disconnection
When the SSE connection drops unexpectedly, follow these five steps to restore continuity: (1) Detect the disconnection event and suppress any error message to the user. (2) Wait for the back-off interval specified in the retry field of the last received event, or default to 3 seconds if none was provided. (3) Re-open the SSE connection using the original session ID and the last known event ID in the Last-Event-ID header. (4) Query the state endpoint to reconcile any events that may have been missed during the gap. (5) Resume normal streaming and notify the user only if the total interruption exceeded a visible threshold.
## 4. Mapping Backend Responses to the User Interface
The backend operates under the assumption that a graphical interface is always present, so the AI must never forward raw GUI-oriented instructions or interface directives directly to the user.
| Backend says | You do |
|-------------|--------|
| "click [button]" / "点击" | Execute via API |
| "open [panel]" / "打开" | Show state via §3.4 |
| "drag/drop" / "拖拽" | Send edit via SSE |
| "preview in timeline" | Show track summary |
| "Export button" / "导出" | Execute §3.5 |
| "check account/billing" | Check §3.3 |
**Keep** content descriptions. **Strip** GUI actions.
## 5. Recommended Interaction Patterns
• Confirm what the user wants to achieve before dispatching any edit request, reducing unnecessary API calls.
• After each operation completes, proactively summarize what changed in the project so the user stays oriented.
• When a silent response occurs, transition smoothly into a state query and report the outcome as if it were a normal reply.
• If a user's request is ambiguous, ask a single focused clarifying question rather than making assumptions.
• Always present export links with a brief description of the file so the user knows exactly what they are downloading.
## 6. Known Limitations
• The AI cannot directly manipulate the timeline or preview window; all edits are mediated through the API.
• Real-time playback within the conversation interface is not supported; users must open the provided URL to preview their clip.
• Concurrent edit operations on the same session are not permitted; requests must be queued sequentially.
• File uploads are subject to the size and format constraints enforced by the upload endpoint and cannot be overridden.
• Credit balances are read-only from the AI's perspective; top-ups must be completed through the platform's billing interface.
## 7. Error Handling Reference
The table below maps each HTTP error code returned by the API to the appropriate recovery action the AI should take.
| 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 at nemovideo.ai" |
| 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 at nemovideo.ai to unlock export." |
| 429 | Rate limit (1 token/client/7 days) | Retry in 30s once |
**Common**: no video → generate first; render fail → retry new `id`; SSE timeout → §3.6; silent edit → §3.1 fallback.
## 8. API Version and Token Scopes
Before making any calls, verify that the API version header matches the version this skill was built against; mismatches may cause unpredictable behavior. The access token must include all required scopes for the operations being performed — specifically the read, write, and export scopes. Tokens missing any of these scopes will result in 403 responses that cannot be resolved without re-authentication by the user.
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