KX-Bridge

Control your Anycubic Kobra X with OrcaSlicer — no Klipper, no Raspberry Pi.

A Moonraker-compatible bridge that talks directly to the printer.

_{🧪 A community report on Reddit suggests the bridge also works with the Kobra S1 and Kobra S1 Max — protocols look compatible, but neither is officially tested or supported. Feedback welcome.}

_{🇩🇪 Deutsche Version · 🇪🇸 Versión española}

     

_{Like KX-Bridge? A coffee on Ko-fi keeps the project alive. ☕}

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Features

🖨️	Printer control — start, pause, resume, cancel, temperatures, print speed
📊	Live status — temperature, progress, layers, remaining time, camera stream
🎨	AMS / multicolor — slots with per-slot profile picker (assign your own brand from OrcaSlicer profiles per slot); bridge writes material & colour back to the printer display
📦	Import your own OrcaSlicer profiles — drag a ZIP from ~/.config/OrcaSlicer/user/<id>/filament/ into the bridge; they show up in the slot dropdown under ★ Own profiles
📷	Obico integration (experimental) — Time-Lapse and WebRTC live stream against a self-hosted Obico server via moonraker-obico
📐	Direct H.264 stream + Z-height — low-CPU camera path for Obico, current Z derived from layer-height for the print-progress widget
🗂️	GCode browser — uploaded files with thumbnails, print history, search & filter
🧩	Multi-printer — multiple printers in one bridge instance, switch via dropdown
➕	Add a printer with one click — just enter the IP, credentials are imported automatically
🔁	Robust MQTT reconnect — bridge survives overnight printer reboots without manual restart
🌐	Multi-language UI — DE / EN / ES / 中文, auto-detect browser locale
🔄	Self-update — install new versions directly in the browser
🧠	OrcaSlicer — full Moonraker protocol (HTTP + WebSocket); pair with the OrcaSlicer-KX build for proper per-slot vendor matching

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Quick Start

1. Prepare the printer

Enable LAN mode on the Kobra X: Printer display → Settings → Enable LAN mode

2. Start the bridge

Docker (recommended):

docker compose up -d

Linux binary (no Docker):

chmod +x kx-bridge-linux-amd64 && ./kx-bridge-linux-amd64

Windows EXE (no Docker):

kx-bridge.exe

⚠️ TLS certificates required for the standalone binary

The bridge talks to the printer's MQTT over mTLS and needs two certificate files right next to the binary:

• anycubic_slicer.crt
• anycubic_slicer.key

Both ship inside anycubic-certs.zip on the same release page. Download it and extract the two files into the same directory as kx-bridge-linux-amd64 / kx-bridge.exe. Without them you'll see Verbindung fehlgeschlagen: TLS-Zertifikate fehlen … (0.9.19.1+) or [Errno 2] No such file or directory (older builds).

Working layout:

~/kx-bridge/
├── kx-bridge-linux-amd64   (or kx-bridge.exe)
├── anycubic_slicer.crt     ← from anycubic-certs.zip
├── anycubic_slicer.key     ← from anycubic-certs.zip
└── config/                 (auto-created on first run)

Docker users don't need to do this — the certs are baked into the image.

With the Linux and Windows binaries, config/ and data/ (settings, SQLite, GCode store) live next to the program. Copy the whole folder = move the installation.

Python directly:

pip install -r bridge/requirements.txt
python bridge/kobrax_moonraker_bridge.py

3. Set up the printer

Open the Web UI: http://BRIDGE-IP:7125

On first start the Printers tab shows "+ Add printer" — just enter the printer's IP address, the rest (username, password, device ID) is fetched from the printer and decrypted automatically. Done.

More than one printer? Just click "+ Add printer" again — each gets its own port (7125, 7126, …) and is selectable from the header dropdown.

4. Connect OrcaSlicer

Printer → Connection type Moonraker → Host: http://BRIDGE-IP:7125

⚠️ Connection type must be Moonraker (not "Bambu" or "Klipper"). Enter the full URL including http:// and port :7125 in the host field.

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Video Tutorial

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Recommended Slicer

For proper AMS filament-sync we ship a patched OrcaSlicer build:

→ OrcaSlicer-KX releases (Linux AppImage + Windows ZIP)

Upstream PRs bundled in the KX build:

• PR #13372 — Moonraker / Happy-Hare AMS sync fix (slot positions stay correct even with empty slots)
• PR #13719 — Vendor + Name matching for Moonraker (reads name + vendor_name per slot and matches against the user's filament presets), by @LordGuenni
• PR #13315 — Unique filament_id for user presets (so newly created custom profiles get a fresh ID instead of inheriting OGFL99 from the generic parent), by @mrnoisytiger

Plus four KX-specific matching improvements on top:

• Respect the bridge filament hint (tray_info_idx + vendor)
• Vendor match also when the chosen base preset is not is_compatible with the active printer (so a profile copied from a different machine still matches by vendor)
• Vendor match when tray_info_idx is set but its preset is incompatible
• Two-pass lookup: first compatible presets, then all visible ones

Why this matters: without #13719 the AMS slots in OrcaSlicer all fall back to Generic PLA / Generic PETG even though the bridge already sends the concrete brand (name + vendor_name + gate_filament_name). With the KX build OrcaSlicer matches your actual user presets — including profiles you imported into the bridge via the Import your own OrcaSlicer profiles flow.

Stock upstream OrcaSlicer still works for slicing and printing — you just lose the per-slot brand matching on AMS sync. Slot material + colour can still be pushed bridge → printer either way (that goes over MQTT, not via the slicer).

OrcaSlicer-KX is a build of OrcaSlicer (AGPL-3.0); source for each upstream PR is on GitHub, KX-specific patches live in the OrcaSlicer-KX repo.

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Community & Integrations

• Home Assistant integration by @gangoke — exposes sensors, print controls, light, camera and the GCode thumbnail as native Home Assistant entities.
• Obico (self-hosted) — the bridge exposes a Moonraker-compatible surface that moonraker-obico accepts, so you get Time-Lapse and WebRTC live streaming against your own Obico server. The AI failure-detection side is experimental on the Kobra X (top-down camera angle differs from what the model was trained on).

These are community projects, not maintained or supported by KX-Bridge. For questions or issues, please use the linked repository.

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Getting credentials manually

Normally not needed — "+ Add printer" does this automatically. If you do need it:

fetch_credentials --ip 192.168.x.x --write-config

Fetches the credentials directly from the printer via HTTP and writes them to config/config.ini. Only the printer IP is required, no slicer.

Alternatively (if the IP is unknown): open AnycubicSlicerNext, connect the printer, then run extract_credentials → outputs username, password, device ID and the printer IP.

Downloads: Releases → fetch_credentials / extract_credentials (Linux & Windows)

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Useful commands

docker compose logs -f                 # show logs
docker compose down                    # stop the bridge
docker compose pull && docker compose up -d   # update to the latest published image
docker compose up -d --build           # rebuild locally (instead of pulling)

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Troubleshooting

"Wrong MQTT credentials" on start

• Re-add the printer via "+ Add printer", or run fetch_credentials --ip <ip> --write-config and restart the bridge
• Enter only the IP address, no port (✗ 192.168.1.102:9883 → ✓ 192.168.1.102)

Printer not found / no LAN mode

• On the printer display: Settings → Enable LAN mode
• Printer and bridge must be on the same network

Docker: Permission denied

sudo usermod -aG docker $USER   # then log out and back in

Upgrading from 0.9.1 or earlier

Starting with 0.9.2, KX-Bridge stores settings in config/config.ini instead of .env. Migration runs automatically on first start after the upgrade — no action required.

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Security

• The bridge is reachable on the local network at http://<host-IP>:7125 — do not expose it to the internet
• config/config.ini contains printer credentials — do not share publicly
• The credentials do not grant access to Anycubic cloud services

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License

KX-Bridge is released under the GNU General Public License v3.0. See LICENSE for the full text. Forks and modifications must remain under GPLv3 if redistributed.

The MQTT protocol implementation is the result of independent reverse-engineering for interoperability purposes (§69e UrhG / EU Software Directive Art. 6). Third-party material in the repository (Anycubic TLS certificates) is not covered by GPLv3 and is included solely to enable authentication against printers the end-user already owns. See NOTICE.md for details and disclaimer.

This project is independent and not affiliated with Anycubic.

If KX-Bridge helps you, the project appreciates your support: