ha-snapmaker-u1

A Home Assistant custom integration for the Snapmaker U1 3D printer, inspired by ha-bambulab.

How it works

The Snapmaker U1 runs a modified Klipper firmware with a modified Moonraker API server. This integration connects directly to that API over your local network using:

• WebSocket (JSON-RPC 2.0) at ws://<printer-ip>/websocket for real-time push updates (no polling delay).
• HTTP REST at http://<printer-ip>/ as a fallback and for sending commands.

No Snapmaker account or cloud connection is required.

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Features

Sensors

Entity	Description
Print State	standby / printing / paused / complete / error / cancelled
Print Progress	Percentage complete
Current Layer	Current layer number
Total Layers	Total layers in the print
Print Duration	Active printing time (excludes pauses)
Time Remaining	Estimated seconds remaining
Filament Used	Millimetres of filament consumed
Filename	Name of the file being printed
Bed Temperature	Current heated-bed temperature
Bed Target	Heated-bed target temperature
T0–T3 Nozzle Temperature	Per-extruder current temperature
T0–T3 Nozzle Target	Per-extruder target temperature
Part Cooling Fan	Fan speed as a percentage
Klipper State	ready / startup / shutdown / error
Toolhead Position	X/Y/Z coordinates (with individual attributes)

Binary Sensors

Entity	Description
Printer Ready	true when Klipper reports ready
Printing	true while a print is actively running
Paused	true while a print is paused
Error	true when a Klipper/print error is active

Buttons

Button	Action
Pause Print	Pauses the active print
Resume Print	Resumes a paused print
Cancel Print	Cancels the active print
Emergency Stop	Immediately halts all motion
Home All Axes	G28
Home X / Y / Z	Home individual axis
Restart Klipper	Restarts the Klipper process

Camera

• Webcam – MJPEG stream from /webcam/stream.mjpg Snapshot images pulled from /webcam/snapshot.jpg

Services

Service	Description
snapmaker_u1.execute_gcode	Send any G-code command or macro
snapmaker_u1.set_bed_temperature	Set heated-bed target (°C)
snapmaker_u1.set_nozzle_temperature	Set a nozzle target (°C) by extruder index

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Installation

HACS (recommended)

1. In HACS → Integrations → three-dot menu → Custom repositories
2. Add this repository URL, category Integration
3. Search for "Snapmaker U1" and install
4. Restart Home Assistant

Manual

1. Copy the custom_components/snapmaker_u1 folder into your HA config/custom_components/ directory.
2. Restart Home Assistant.

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Configuration

1. Go to Settings → Devices & Services → Add Integration
2. Search for Snapmaker U1
3. Enter:
   • IP Address – the local IP of your printer (e.g. 192.168.1.42)
   • Port – 80 by default (Moonraker is proxied through nginx)
   • API Key – leave blank unless you have configured Moonraker authentication

The integration will test the connection before saving. If successful, all entities are created immediately.

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Authentication

The stock U1 firmware configures Moonraker with trusted LAN clients, so no API key is required if Home Assistant is on the same network as the printer.

If you use the Extended Firmware with forced logins enabled, generate an API key in Moonraker and paste it into the API Key field.

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Troubleshooting

Symptom	Fix
"Cannot connect" during setup	Verify the IP, confirm the printer is on and that Fluidd loads in your browser at that address
Sensors stuck at unavailable	Check Klipper logs via Fluidd; the WebSocket may be reconnecting
Camera shows no image	Ensure the webcam is enabled in Moonraker's config; test http://<ip>/webcam/snapshot.jpg directly
Temperatures show 0 after startup	Klipper may still be initialising; state will update within seconds once ready

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Technical notes

• Protocol: Moonraker WebSocket (JSON-RPC 2.0) + HTTP REST
• IoT class: local_push (push updates via WebSocket, no cloud dependency)
• Reconnection: Exponential back-off from 5 s to 60 s
• Extruders: Up to 4 nozzles auto-detected (T0–T3)
• HA version: Tested against Home Assistant 2024.1+

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Credits

Architecture inspired by ha-bambulab by Greg Hesp and Adrian Garside.

Moonraker API documentation: https://moonraker.readthedocs.io