FULU setup: open-source slicing and printer connections

We support FULU Foundation, Louis Rossmann, and the OrcaSlicer-bambulab community. Owners should be free to repair their printers, choose open-source software, and print without a vendor cloud. That commitment belongs alongside the setup instructions, not just in a credits footer.

Choose your workflow

Workflow	What you need	Bambu software/services in the print path
FULU GUI export → MCP direct LAN	FULU slicer, sliced project, printer IP/serial/access code, supported LAN firmware	No Bambu Studio, Bambu Connect, or Bambu Cloud required by this workflow
FULU BambuNetwork bridge, LAN	Separately installed bridge host/runtime, local credentials, shared file access	Uses Bambu's networking libraries through FULU's bridge
FULU BambuNetwork bridge, cloud	Bridge runtime, internet access, authenticated BambuNetwork session, device ID	Still uses Bambu's networking libraries and cloud services

The first workflow is the place to start if you want to skip Bambu's software and cloud for slicing and printing. The hardware is still a Bambu printer, with model- and firmware-specific capabilities. This repository does not replace printer firmware or add other manufacturers' printer adapters.

Setting SLICER_TYPE=orcaslicer-bambulab selects a slicer; it does not activate BambuNetwork, log in, or change the default print_3mf transport. Bridge printing is explicitly selected with print_3mf_bambu_network or print_3mf plus connection_mode: "bambu_network".

Start with FULU export and direct LAN

1. Obtain FULU OrcaSlicer-bambulab from its upstream project and installation instructions. Follow the instructions for your build and operating system; the MCP npm package does not contain the slicer or its networking runtime.
2. Enable the printer's LAN / Developer Mode settings for direct third-party control. Record its IP, serial number, and LAN access code.
3. Install the MCP and configure your client using the client configuration example. At minimum, set the following in the server's environment, replacing the sample values:

PRINTER_HOST=192.168.1.100
BAMBU_SERIAL=YOUR_PRINTER_SERIAL
BAMBU_TOKEN=YOUR_LAN_ACCESS_CODE
BAMBU_MODEL=p1s

4. In FULU, select the exact printer, nozzle, bed, and loaded filaments. Slice, inspect the preview, and export the sliced plate as .gcode.3mf, not an unsliced project. See the slicing recipe.
5. Call get_printer_status first. When ready to print, call print_3mf with the exported file and the correct material selection. For a single-filament plate using AMS tray 2:

{
  "three_mf_path": "/absolute/path/bracket.gcode.3mf",
  "bambu_model": "p1s",
  "ams_slots": [2],
  "use_ams": true
}

For an external spool, follow the no-AMS guidance. H2 jobs with declared filaments still need the positional mapping described in print_3mf. Inspect printer status and HMS errors after submission; command acceptance and actual printing are different checks.

X2D: status and slicing with its own preset are supported. On macOS, print_3mf can use the optional native eMMC helper and installed compatible networking plug-in, with shared model/file/state/preflight checks. Linux/Windows native printing and legacy FTPS/remote-file starts remain unsupported. A successful FULU slice or bridge initialization alone does not demonstrate physical printing; do not substitute h2d. See the slicing and transport guide.

FULU and Orca CLI safety checks

Starting with 1.1.11, FULU and Orca use the same MCP machine-preset gate and BBL profile preparation as BambuStudio. The server requires the exact model/nozzle preset from the selected profile tree. A missing or malformed preset stops slicing; a custom slicer_profile only supplies process settings and cannot replace the machine preset.

Set these in the environment used to launch the MCP server, replacing paths with your installed FULU or Orca build:

export SLICER_TYPE=orcaslicer-bambulab  # or orcaslicer; fulu-orca and orca-studio aliases also work
export SLICER_PATH=/absolute/path/to/your/slicer
export BAMBU_PROFILES_ROOT=/absolute/path/to/its/resources/profiles
export BAMBU_MODEL=p1s                # your exact printer model
export NOZZLE_DIAMETER=0.4           # your installed nozzle diameter

BAMBU_PROFILES_ROOT is the directory containing BBL, including the machine, process, filament, and cli_config.json files from that same slicer installation. It is optional when the tree is discoverable beside the executable. For AppImage or custom installations, point it to the matching extracted resources. The server does not borrow a missing machine from another installation. Configured user-profile directories remain available for custom process and filament dependencies, but cannot supply machine ancestors.

When multiple Orca/OrcaStudio variants share one Linux install prefix, set BAMBU_PROFILES_ROOT explicitly: automatic discovery does not distinguish those co-installed variants.

Before launching the CLI, the MCP resolves inherits and include, validates the selected model's CLI configuration, and prepares every filament slot. Missing references, cycles, malformed configuration, and incomplete slot mappings stop preparation. Failed auto-slicing stops before upload or print dispatch; the original unsliced project is never used as a fallback.

The regression suite verifies these checks, alias routing, and generated CLI settings using isolated profile trees and fake executables. It does not establish live FULU/Orca slicing or physical printing across versions and platforms. Start with slice_stl, inspect the output in the slicer, and use GUI export if your build rejects CLI flags or lacks the required profiles. The existing BambuStudio version evidence remains specific to BambuStudio.

Configure the bridge

This is an optional, advanced connection path. The MCP implements the framed stdin/stdout protocol expected by FULU's bridge host. It does not install that runtime, provision a VM, or supply a cloud-login UI.

Setting	Purpose
BAMBU_NETWORK_BRIDGE_COMMAND	Full trusted shell command for the host binary or platform wrapper. Do not point this at the slicer GUI or another MCP server.
BAMBU_MODEL	Exact target printer model; required for printing.
BAMBU_DEV_ID	Fallback device ID if no printer serial is resolved. An explicit tool dev_id takes priority over the serial and this setting; use it when several printers are configured.
BAMBU_NETWORK_CONFIG_DIR	Persistent writable agent config/log directory. Default: ~/.config/bambu-printer-mcp/bambu-network.
BAMBU_NETWORK_COUNTRY_CODE	Region/country passed to the runtime, default US; use the appropriate setting for your account.
BAMBU_NETWORK_USER_INFO	Optional sensitive JSON passed to net.change_user; see cloud authentication.
PJARCZAK_BAMBU_PLUGIN_DIR	Upstream runtime's library directory, containing the matching network/source libraries.

Set these where your MCP client launches the server. Desktop applications may not inherit variables exported in a terminal. Restart the server after changes. Keep the command in trusted client configuration; do not enable per-call bridge_command overrides just to follow this guide.

Linux

Use a FULU runtime built for your CPU architecture. It must include the bridge executable and matching libraries such as libbambu_networking.so and libBambuSource.so. The upstream host sources and packaging script describe that component; installing upstream OrcaSlicer alone does not establish that the FULU host is present.

For a shell-launched MCP, this is the configuration shape; replace both paths with your actual installation:

export BAMBU_NETWORK_BRIDGE_COMMAND="'/opt/fulu-runtime/pjarczak_bambu_linux_host'"
export PJARCZAK_BAMBU_PLUGIN_DIR=/opt/fulu-runtime
export BAMBU_NETWORK_COUNTRY_CODE=US
export BAMBU_DEV_ID=YOUR_DEVICE_ID
export BAMBU_MODEL=p1s
npx -y bambu-printer-mcp

Use the same variable values in a desktop client's env object. Quote paths containing spaces inside the bridge command. Proceed to the probes below before attempting a print.

Windows / WSL 2

FULU's installation instructions require WSL 2 and a restart after enabling its Windows features. Follow those instructions for the slicer/runtime build you install.

For MCP bridge testing, running both the Node.js MCP server and Linux bridge host inside the same WSL environment avoids passing Windows paths to a Linux process. Install Node.js/npm there, use the Linux settings above, and reference shared files with paths such as /mnt/c/Users/yourname/Downloads/bracket.gcode.3mf. The MCP and bridge must both be able to read that exact path. Configure a desktop MCP client to launch the server in that WSL environment, with the bridge settings available there.

A native Windows MCP calling wsl.exe only for the bridge needs a wrapper that translates paths in both directions or otherwise makes identical paths accessible. This MCP forwards file paths unchanged; a Windows C:\... path is not automatically converted to /mnt/c/.... Do not mistake a successful handshake for a working upload.

macOS

As checked on 2026-09-27, FULU's upstream README still labels macOS a work in progress. The MCP has runtime discovery hints, but it does not provide a turnkey macOS installer.

Start with bambu_network_bridge_status and {}. It inspects these conventional locations without launching a process:

~/Library/Application Support/OrcaSlicer/plugins/
~/Library/Application Support/OrcaSlicer/macos-bridge/runtime/

When it finds the wrapper, the response includes runtime.suggestedMacCommand. Copy it to BAMBU_NETWORK_BRIDGE_COMMAND only after confirming the paths exist. A typical installed Lima-wrapper command has this shape:

export BAMBU_NETWORK_BRIDGE_COMMAND="PJARCZAK_BAMBU_PLUGIN_DIR='$HOME/Library/Application Support/OrcaSlicer/macos-bridge/runtime' '$HOME/Library/Application Support/OrcaSlicer/plugins/pjarczak-bambu-linux-host-wrapper' '$HOME/Library/Application Support/OrcaSlicer/macos-bridge/runtime/pjarczak_bambu_linux_host'"

The upstream Lima wrapper needs an already prepared Linux instance, the correct host architecture, and mounted files. It accepts PJARCZAK_MAC_LIMA_INSTANCE for the instance name and PJARCZAK_LIMACTL for a specific limactl executable. Follow the runtime instructions shipped with your FULU build; older install/verify scripts are not guaranteed to be included in every current package.

The Linux guest must see the project file and writable config/log directory at the same absolute paths the MCP passes. A Docker/VM wrapper that mounts only the runtime libraries is insufficient for printing. If files are missing or the host crashes with an architecture error, resolve the upstream runtime installation before trying print commands.

Probe without printing

Use these MCP calls in order:

1. bambu_network_bridge_status with {} reports configuration, process state, and macOS discovery hints without starting the bridge.
2. bambu_network_bridge_status with {"connect": true} launches the host, performs bridge.handshake, and initializes the network agent. It creates/uses the config directory and contacts the network service, but does not submit a print.
3. bambu_network_call with {"method": "net.is_user_login", "payload": {}} checks the runtime's login state before a cloud job.

Check the returned handshake, agentReady, and any errors. The macOS file hints are not Linux/Windows requirements. Agent initialization alone does not establish cloud login, printer reachability, or print success. The MCP can retry the handshake using the reported network ABI version when the runtime reports an expected-version mismatch; avoid hard-coding an old ABI version from a sample.

For raw bridge.handshake, call bambu_network_call with with_agent: false. Other raw methods can change state; consult your installed FULU bridge's method contract.

Cloud authentication

The bridge's default config directory is separate from the slicer's. Logging into the FULU GUI does not automatically prove that this MCP's bridge agent is logged in.

Use the authentication/session configuration supported by your installed runtime and verify it with net.is_user_login. If that runtime supplies a compatible user_info JSON value, BAMBU_NETWORK_USER_INFO passes it to net.change_user after agent initialization. It is not your plain account password, and this project does not define a universal token schema or automatically copy the GUI's session. Use an authenticated config directory only when supported by your runtime, with the correct region and filesystem access.

If login cannot be established, stop at the probe and use direct LAN where supported, or use FULU's own UI. Cloud bridge jobs still require Bambu services; they are not the cloud-free workflow described at the top of this guide. Keep tokens, access codes, account JSON, and unredacted logs out of public issues.

Print through the bridge

These examples submit real print jobs. Run them only after checking the sliced preview, printer model, material mapping, runtime, and authentication. They are not connection tests.

Call print_3mf_bambu_network for a single-filament cloud job assigned to AMS tray 0:

{
  "three_mf_path": "/absolute/shared/path/bracket.gcode.3mf",
  "bambu_model": "p1s",
  "dev_id": "YOUR_DEVICE_ID",
  "connection_type": "cloud",
  "plate_index": 0,
  "use_ams": true,
  "ams_mapping": [0]
}

For a LAN bridge job, use the same tool and explicitly select LAN:

{
  "three_mf_path": "/absolute/shared/path/bracket.gcode.3mf",
  "bambu_model": "p1s",
  "dev_id": "YOUR_DEVICE_ID",
  "dev_ip": "192.168.1.100",
  "bambu_token": "YOUR_LAN_ACCESS_CODE",
  "connection_type": "lan",
  "plate_index": 0,
  "use_ams": true,
  "ams_mapping": [0]
}

For the equivalent print_3mf calls, add connection_mode: "bambu_network". Its default remains direct LAN; the dedicated bridge tool defaults to connection_type: "cloud". Every bridge print requires a reachable printer IP, LAN access code, and matching serial/device ID for fresh local MQTT safety verification, including cloud submission through an authenticated runtime. A cloud-only connection without local safety telemetry cannot authorize a print.

plate_index is zero-based in MCP calls and converted to one-based for FULU. ams_mapping is positional across project filaments; [0] above is only for a one-filament project. ams_slots expands into those project positions before verification. Raw mapping, nozzle, configuration-file and extra-option overrides are refused so they cannot replace the checked job. Use the structured model, nozzle, plate, and AMS arguments. The raw bambu_network_call tool permits only named read-only probes.

bambu_network_method	Runtime call	Default/use
start_print	net.start_print	Default for cloud
start_local_print	net.start_local_print	Default for LAN
start_local_print_with_record	net.start_local_print_with_record	Local job with task-record behavior
start_send_gcode_to_sdcard	net.start_send_gcode_to_sdcard	Advanced runtime-specific transfer
start_sdcard_print	net.start_sdcard_print	Advanced runtime-specific SD-card start

Non-zero numeric bridge results are errors. A successful submission does not prove that the printer starts or finishes the job. For LAN, inspect get_printer_status and HMS diagnostics; for a cloud-only connection, check the runtime/slicer UI and printer. Ordinary MCP status, camera, pause/resume, and file tools still use the direct local connection.

Troubleshooting and evidence to report

Symptom	Next check
configured: false	Set BAMBU_NETWORK_BRIDGE_COMMAND in the MCP process environment and restart it.
Invalid frame magic or immediate exit	Confirm the command starts the binary-protocol host, not the GUI; wrapper stdout must contain only protocol frames.
Missing library / architecture / VM error	Check the matching upstream runtime, CPU architecture, library directory, and platform wrapper.
Handshake works, file upload fails	Verify the project and config paths inside the host/VM/WSL process, including read/write permissions.
Agent ready, cloud print rejected	Verify login, region, and device ID; agentReady is not an authenticated-session guarantee.
Non-zero result or send msg failed	Inspect the redacted runtime error and printer diagnostics; do not blindly repeat a possible print submission.
FULU/Orca CLI slicing requested	Use 1.1.11+ with the matching installed profile tree and exact model/nozzle; see the CLI checks above. Use GUI export if preparation or slicing fails.
X2D native transport unavailable	Native printing requires macOS, the optional built helper, and a compatible installed networking plug-in. Legacy FTPS/remote-file starts remain unsupported; keep the X2D model and preset.

The repository's automated tests exercise mocked bridge framing, initialization, method/parameter handling, and failure responses. They do not certify live FULU printing on Linux, Windows, or macOS. Earlier macOS experiments reached a handshake but encountered print-start failures; they are not current physical-print validation. No physical print is performed as part of this documentation sweep.

For a useful issue report, include MCP version, OS/CPU, printer model and firmware, slicer/runtime version, direct-LAN versus bridge/cloud selection, method used, redacted error, and whether the printer actually started. Credit both working and failing hardware evidence so future compatibility claims remain specific.