Camclave

camclave

camclave lets you see single still frames from the user's webcam. The user must have explicitly run camclave start to consent to this session; otherwise capture refuses.

There is no video capture. Every frame that lands on disk is the result of an explicit capture or scheduled snapshots write. There is no rolling buffer, no continuous recording path, no streaming. The daemon never instantiates cv2.VideoWriter and never writes any video container.

How to use it (agent-side)

Before calling anything, check the session is active:

camclave status

If no session is active, do not retry. Tell the user: "I need to see your camera. Please run camclave start in another terminal, then ask me again." That is the consent contract — the agent never instructs the user to start the session as part of an in-flow action; the user must initiate it.

To grab one frame (most common):

camclave capture --reason "read the multimeter LCD"

Always pass --reason. The reason flashes in the preview window's footer for 4 seconds after the capture and is written to `/.camclave/audit.jsonl`. This is the user's audit trail — they should be able to glance at the screen and see exactly why each capture happened.

camclave capture (no reason) still works but logs (no reason given) and the agent SHOULD NOT use that form unless the user explicitly told it to.

Prints an absolute PNG path on stdout. Read the PNG with your image-reading tool. The preview window flashes warm cream and beeps the moment the frame is captured.

To watch over time (e.g. 3D print baby-sitting, plant logging):

camclave snapshots --every 30s --duration 10m --out /tmp/latest.png

The daemon overwrites --out on every interval. Re-read the file when you want a fresh look. Stop early with camclave snapshots-stop.

To adjust camera properties (e.g. dim breadboard, glare on an LCD, autofocus hunting on a small target):

camclave adjust --show                              # read current values first
camclave adjust --brightness 0.7 --exposure -5
camclave adjust --auto-focus 0 --focus 120          # disable autofocus and pin focus

Supported: brightness, contrast, saturation, hue, gain, exposure, focus, zoom, sharpness, gamma, auto_exposure, auto_focus, auto_wb, wb_temperature. Values are backend-dependent — most are 0..1; exposure is usually negative on Windows DSHOW; auto-* toggles are 0=off / 1=on (DSHOW quirk: 0.25 = manual, 0.75 = auto). The CLI reports what the camera actually accepted vs. what you asked for.

Other:

camclave devices [--preview]   # probe / visually identify cameras
camclave doctor                # one-screen diagnostic if anything's off
camclave status                # active session + last 5 captures with reasons

Rules the agent must follow

1. Always pass --reason "..." on capture. The user is watching a flashing window — give them a one-line why. Examples: --reason "verify LED on D5", --reason "read multimeter LCD". Skip only if the user explicitly says "no reason needed".
2. Never call capture without explaining first. Say what you're about to look for so the user can frame the shot.
3. One frame at a time, on demand. Never burst. Don't loop capture to simulate a video stream. If you need periodic visibility, use snapshots with a sensible interval (≥2s — the CLI clamps lower values).
4. Respect the TTL. If status shows the session is nearly expired, finish up rather than start a long task.
5. No upload. Don't send the captured PNG to any remote service unless the user explicitly asks.
6. Honor --no-sound and the user's window. Don't try to suppress flashes or move the preview window.
7. Try adjust --show before changing anything. If the first frame is too dark / blurry, prefer one targeted property tweak (e.g. raise brightness or disable auto_focus) over taking many bad frames.

See references/consent.md and references/safety.md for the full contract, and references/use-cases.md for patterns.