| name | webcam-snap |
| description | Take a still photo from a local V4L2 webcam (/dev/video0) with ffmpeg, then read/analyze or send the image. Trigger when the user asks to "take a photo", "take a picture", "selfie", "拍照", "自拍", "看看现在的环境/房间", or when Claude needs to visually observe the physical environment through the machine's camera. Linux-only; requires ffmpeg and a V4L2 device. |
Webcam Snap
Capture a single frame from the machine's local webcam, then either read the JPEG (multimodal models can see it directly) or send it to the user.
Capture (primary — no path dependency)
Run this one-liner. It skips the first 30 frames so auto-exposure settles before the frame is grabbed:
ffmpeg -y -loglevel error -f v4l2 -video_size 1280x720 -i /dev/video0 \
-vf "select=gte(n\,30)" -frames:v 1 -vsync 0 -f image2 /tmp/selfie.jpg
Lower-resolution / fastest fallback:
ffmpeg -y -f v4l2 -i /dev/video0 -frames:v 1 -f image2 /tmp/selfie.jpg
Helper script (optional)
This skill also ships scripts/take_selfie.sh, which adds the exposure warm-up, device auto-fallback (tries the next /dev/video* if video0 is missing), and dependency checks. Invoke it from the skill directory:
bash scripts/take_selfie.sh /tmp/selfie.jpg 1280x720
Arguments are optional: take_selfie.sh [output_path] [resolution] (defaults: /tmp/selfie_<timestamp>.jpg, 640x480).
After capture
- To analyze the scene: use the Read tool on the JPEG — a multimodal model sees the image directly, no extra script needed.
- To hand it to the user: send the JPEG through whatever the host supports (e.g. Claude Code's file-send /
SendUserFile).
Environment
- Device:
/dev/video0 (machines often also expose /dev/video1)
- Dependency:
ffmpeg (sudo apt install ffmpeg on Debian/Ubuntu)
- Permissions: the user must be able to read the video device. If not, add them to the
video group.
Troubleshooting
| Symptom | Fix |
|---|
Cannot open video device / permission denied | sudo usermod -a -G video $USER (re-login), or temporarily sudo chmod 666 /dev/video0 |
/dev/video0 not found | ls -la /dev/video* and use another index; the helper script auto-falls-back to the first available device |
| Frame is black or over-exposed | raise the warm-up count (e.g. gte(n,60)) or bump the resolution |
| List devices / formats | v4l2-ctl --list-devices, ffmpeg -f v4l2 -list_formats all -i /dev/video0 |
Scope
- In scope: local USB / built-in webcams exposed as V4L2 (
/dev/video*) on Linux.
- Out of scope: network/IP cameras (RTSP/ONVIF), macOS/Windows capture, video recording. These need different tooling and are intentionally not handled here.
