Overview#
Investigation into whether the Prusa Buddy3D Camera can be used to capture print-end snapshots locally via PrusaLink for The Moment print history. Triggered by implementing a camera snapshot feature that correctly handled the API response but produced no images on a real print.
Setup#
| Component | Detail |
|---|---|
| Printer | Prusa Core One L |
| Printer firmware | 6.5.3+12780 |
| PrusaLink API version | 2.0.0 |
| Camera | Buddy3D Camera (Guardian PR1), firmware 3.1.3 |
| Camera connectivity | Wi-Fi 2.4 GHz, own IP address on LAN |
What Was Implemented#
The Moment’s camera snapshot feature queries GET /api/v1/cameras on the printer, then calls GET /api/v1/cameras/{id}/snap to capture a JPEG. This endpoint exists in the PrusaLink OpenAPI spec and was confirmed in the spec for the Raspberry Pi-based PrusaLink (used on MK3/MK4/MK3.9 printers).
Findings#
/api/v1/cameras returns 404 on Core One L#
The endpoint is not implemented in the Core One L’s Buddy board firmware. The Buddy board exposes a PrusaLink-compatible API, but camera management is not part of it because the Buddy3D Camera is a separate network device, not a USB camera attached to the printer’s board.
GET http://<printer-ip>/api/v1/cameras
→ 404 Not FoundThis is not a bug in The Moment. The code correctly treats 404 as “no camera” and silently no-ops. No crash, no error, no snapshot.
Buddy3D Camera architecture#
The Buddy3D Camera (Guardian PR1) is a standalone Wi-Fi camera with its own IP address. It is not proxied through the printer’s PrusaLink API.
| Access method | Available | Notes |
|---|---|---|
GET /api/v1/cameras on printer | ❌ No | Printer firmware does not implement it |
| HTTP snapshot endpoint on camera | ❌ No | No HTTP API on the camera itself |
| RTSP stream | ✅ Yes | rtsp://<camera-ip>/live, port 554, LAN only |
| PrusaConnect cloud snapshots | ✅ Yes | Automatic, every 10–90 s, requires cloud auth |
| ONVIF / REST API on camera | ❌ None native | go2rtc or similar proxy required |
RTSP stream#
The camera exposes an unencrypted RTSP stream on the local network when enabled via the Prusa app:
rtsp://<camera-ip>/live
rtsp://admin:admin@<camera-ip>:554/live (alternate format seen in the wild)A still frame can be captured from this stream using ffmpeg or a Go RTSP library, but requires knowing the camera’s separate IP address.
Options Going Forward#
Option A — Add configurable snapshot URL per printer (recommended)#
Add an optional CameraSnapshotURL field to the printer config. If set, The Moment fetches from that URL instead of (or in addition to) trying /api/v1/cameras. Supports:
- Any HTTP/HTTPS endpoint returning a JPEG
- RTSP via ffmpeg exec or Go RTSP library
Users with the Buddy3D Camera configure the RTSP URL. The existing PrusaLink camera API fallback remains active for Pi-based printers.
Option B — Wait for firmware update#
Prusa may add /api/v1/cameras support to Buddy board firmware in a future version. If/when they do, The Moment’s existing code activates automatically. No action required today.