The full upstream README, mirrored for reference. Install config, tool schemas, adoption signals and our own overview live on the Bambu Printer MCP listing page.
Thank you, FULU Foundation, Louis Rossmann, and the OrcaSlicer-bambulab contributors. We stand with open-source developers, the right to repair, and your right to control hardware you own. You should be able to choose your software and print without a vendor cloud standing in the way.
Want to skip Bambu's software and cloud? Use FULU OrcaSlicer-bambulab to slice and export, then this MCP's direct LAN path on supported printers and firmware. That workflow does not require Bambu Studio, Bambu Connect, or Bambu Cloud. Start with the FULU setup guide. The optional BambuNetwork bridge is a separate path that still uses Bambu's networking runtime; cloud jobs still use Bambu's services.
A Bambu Lab-focused MCP server for controlling Bambu printers, manipulating STL files, and managing end-to-end 3MF print workflows from Claude Desktop, Claude Code, or any MCP-compatible client.
Browse the documentation site for searchable setup guides, slicing and AMS guidance, and the full tool reference. It is generated from this README and the docs folder.
Built with help from our contributors. Huge thanks to everyone sharing fixes, careful bug reports, and real printer testing!
This is a stripped-down, Bambu-only fork of mcp-3D-printer-server. All OctoPrint, Klipper, Duet, Repetier, Prusa Connect, and Creality Cloud support has been removed. What remains is a focused, lean implementation for Bambu Lab hardware.
Set up with your agent
Tell your agent your printer's model and LAN address, if you know them, then copy and paste this:
text
Install bambu-printer-mcp in the agent/harness I'm using now.
Read https://github.com/DMontgomery40/bambu-printer-mcp/blob/main/docs/SETUP.md
and https://github.com/DMontgomery40/bambu-printer-mcp/blob/main/docs/FULU.md
for the current setup instructions and supported workflows.
Detect my OS and harness, then use its native MCP configuration or installer.
Preserve my existing servers and settings. Prefer the published npm package
(npx -y bambu-printer-mcp, stdio); use Node.js 24if a runtime is needed.
Find existing printer settings in relevant local configuration or available
LAN discovery. Confirm the detected printer's model, address, and identity
with me before connecting. Ask only for values you cannot find:
PRINTER_HOST, BAMBU_MODEL, BAMBU_SERIAL, and BAMBU_TOKEN (the LAN access code).
Keep credentials in local/private configuration; do not repeat access codes
or tokens in chat. Never guess the printer model.
Use direct LAN printing by default. Explain any LAN/Developer Mode setting
I need to enable. Prefer FULU OrcaSlicer-bambulab GUI slicing/export; discover
an existing slicer before suggesting an install. For FULU/Orca CLI auto-slicing,
require MCP 1.1.11+ and its matching installed profile tree (see guide).
A slicer is not needed here to print a pre-sliced file. Configure the optional FULU
BambuNetwork bridge only if I choose it, and explain its runtime/auth needs.
X2D supports status and slicing; native printing requires macOS or x86-64 Linux and a locally built helper.
If this harness does not already provide code mode or an equivalent, suggest
a compatible code-mode integration as an optional addition. It is not required;
finish ordinary MCP setup without it unless I choose to add it.
Verify that the MCP initializes, lists its tools, and reads printer status.
Do not start a print or change printer settings as a setup test. Tell me what
worked and whether I need to restart or reload the harness.
Ask for the result you want, not the steps. Current models plan across tools: they search the web, read photos, look up exact dimensions, edit models, slice, and print. Expect a question or two when a choice matters, such as which filament to use or whether to start the print.
This server provides the printer, slicing, AMS, and mesh tools. Web search, photos, and Blender edits come from your agent and its other connections, such as a Blender MCP server. Printing a model your agent edited uses CLI slicing with your installed slicer presets; see the slicing guide.
Start from anything
"Here's a phone stand on MakerWorld. Make it fit the new iPhone and print it in black."
Your agent looks up Apple's published dimensions, adjusts the stand in Blender, slices it for your printer, and finds the AMS tray with black filament.
"I want one of these."(with a photo of a planter you saw at a café)
It works out the shape and size from the photo, finds or models a matching design, and asks about anything the photo can't show.
"Can you print a replacement?"(with a photo of a snapped dishwasher rack clip)
It asks for a measurement or two where the fit matters, models the part, and prints it in a loaded material that suits the job.
From anywhere, while it prints
If your agent is always on, such as OpenClaw or Hermes Agent running on a computer at home, message it from Telegram or any other chat app. For direct LAN printing, the server runs on the printer's local network; you don't have to.
"How's the print going? Send me a picture."
It reports progress and time remaining, and sends a snapshot from the chamber camera.
"The corner is lifting. Pause it."
It pauses the job so you can decide whether to resume or cancel.
"One of the parts came loose. Skip it and keep printing the rest."
It finds that object on the plate and skips only that one.
"Start drying the PETG so it's ready when I get home."
On a heated AMS, it starts the drying cycle for the unit holding that spool.
Before you print
"Take a picture and make sure the bed is clear, then start the bracket I sliced last night."
It checks the camera image before it sends the job.
"What's loaded in the AMS? Print this in whatever black I have."
It reads the live AMS inventory and matches the file's filaments to your trays.
"Are there any errors on the printer?"
It reads the printer's HMS diagnostics and explains them.
Start here
Start here
I want to…
Read next
Use open-source slicing and a cloud-free print workflow
See the changelog for versioned changes. Recent releases add reliable npm and desktop-extension installs, standard Blender MCP integration, corrected P2S/A1 routing, and safer multi-filament CLI slicing. X2D status and slicing are available, with optional native printing on macOS through the installed Bambu Studio networking plug-in.
bambu-printer-mcp is a Model Context Protocol server for Bambu Lab 3D printers. A straightforward workflow is: slice in FULU OrcaSlicer-bambulab, OrcaSlicer, or Bambu Studio, export a sliced .gcode.3mf, then pass its path to print_3mf. The default direct LAN path uploads via FTPS and chooses the MQTT command for the target model. See the slicing guide for CLI options, model routing, and validation limits.
What this is not. This package intentionally supports only Bambu Lab printers. It does not include adapters for OctoPrint, Klipper (Moonraker), Duet, Repetier, Prusa Connect, or Creality Cloud. If you need multi-printer support, use the parent project mcp-3D-printer-server instead.
Why a separate package? The parent project carries all printer adapters in a single binary. When working exclusively with Bambu hardware, that breadth adds unnecessary weight. This fork strips the project to its Bambu core for a smaller, faster install. See each project's changelog for its current fixes and supported workflows.
Note on resource usage. STL manipulation loads entire mesh geometry into memory. For large or complex STL files (greater than 10 MB), these operations can be memory-intensive. See General Limitations and Considerations for details.
FULU and open-source printing
FULU and open-source printing
FULU OrcaSlicer-bambulab is a supported slicer target (SLICER_TYPE=orcaslicer-bambulab; aliases include fulu-orca and orca-studio). Use its GUI to export a sliced project for direct LAN printing, or configure its CLI with matching installed profiles. From 1.1.11, FULU/Orca share the machine-preset gate and profile safety checks.
The optional FULU BambuNetwork bridge exposes bambu_network_bridge_status, bambu_network_call, and print_3mf_bambu_network, also reachable through print_3mf with connection_mode: "bambu_network". Slicer selection does not enable the bridge. It needs a separately installed FULU runtime and an explicit launch command; cloud printing also needs an authenticated BambuNetwork session.
Follow the FULU setup guide for the direct LAN recipe, Linux/Windows/macOS bridge setup, connection probes, authentication, and troubleshooting. Bridge protocol tests and a successful handshake do not establish a successful physical print.
Features
Features
Get detailed printer status: temperatures (nozzle, bed, chamber), print progress, current layer, time remaining, and live AMS slot data
Query live AMS inventory with resolved Bambu/Orca filament profile paths via get_printer_filaments. Profile suggestions use the selected slicer installation on Windows, macOS and Linux, including an explicit BAMBU_PROFILES_ROOT; unavailable profiles leave live inventory readable. Includes per-tray display names, match confidence (high/medium/low/none), resolution tier (exact-model-nozzle/model/generic/unresolved), and a summary with recommended auto-slice filament. Retries automatically when AMS data hasn't arrived yet (common on first MQTT push from idle printers).
List, upload, and delete files on the printer's SD card via FTPS
Capture a JPEG snapshot from the chamber camera. Supports A1, A1 mini, P1S, P1P (TCP-on-6000), and X1, X1C, X1E, P2S, H2, H2S, H2D, H2C, H2D Pro, X2D (RTSP via ffmpeg). Requires ffmpeg in PATH for the RTSP path.
Upload and print pre-sliced .3mf projects with checked plate selection and calibration flags. Legacy .gcode.3mf routes require a single external-spool-only plate; see the slicing guide.
Slice through BambuStudio CLI with automatic BBL inheritance/include resolution, per-slot filament colours, and fallback prime-tower placement for multi-nozzle printers. Missing dependencies stop the slice; custom settings and saved project tower positions are preserved. Multi-colour slicing is verified by the contributor on BambuStudio 02.08.02.60 for Windows; older CLI versions have separate limitations. See slicing guide.
Recognize X2D status and slice with its own installed BambuStudio preset (BAMBU_MODEL=x2d). On macOS and x86-64 Linux, print_3mf selects the native eMMC route after resolving the model, including an elicited model. Install the optional helper as described below; Windows native print requests, and Linux requests without the helper, fail before slicing or contacting the printer. Legacy FTPS and remote G-code starts remain unsupported for X2D.
Parse AMS mapping from the 3MF's embedded slicer metadata ( + gcode filament header) and send it correctly formatted per the OpenBambuAPI spec, with correct H2S/H2D/H2C parallel array format
AMS (Automatic Material System) Setup
AMS (Automatic Material System) Setup
The Bambu AMS is a multi-spool feeder that lets you assign different filaments to different parts of a multi-color or multi-material print. This section explains how AMS slot mapping works with this MCP server.
How AMS slots work
The AMS has 4 slots per unit, numbered 0 through 3. If you have multiple AMS units chained together, the second unit's slots are 4 through 7, and so on. When you slice a model in Bambu Studio or OrcaSlicer, each color/material in the print is assigned to a specific AMS slot.
Automatic AMS mapping from the 3MF
When you slice a model in Bambu Studio, the slicer embeds AMS mapping information inside the 3MF file at Metadata/project_settings.config. The print_3mf tool reads this file automatically and extracts the correct mapping. In most cases, you do not need to specify ams_mapping manually -- the tool handles it.
Manual AMS mapping
If you need to override the embedded mapping (for example, you swapped filament positions since slicing), pass the ams_mapping array to print_3mf:
Each element in the array corresponds to a filament slot used in the print file, in the order they appear in the slicer. The value is the physical AMS slot number (0-based) where that filament is currently loaded. In the example above, the first filament in the print uses AMS slot 0, and the second uses AMS slot 2.
Mapping is positional: each entry corresponds to a project filament, and -1 means unused. H2/P2S project-file commands use project-length mapping plus a parallel ams_mapping2; other project-file routes retain at least five positions without truncating longer projects. Prefer ams_slots in plate filament order or auto_match_ams: true when you do not already have the full project mapping.
Single-material prints
For a single-material plate, explicitly select its loaded tray. For example, use AMS slot 2:
For H2 projects with declared filaments, also provide the required mapping; alone does not remove the firmware's mapping requirement. See .
Bambu Communication Notes (MQTT and FTP)
Bambu Communication Notes (MQTT and FTP)
Bambu Lab printers do not use a conventional REST API. Instead, they expose two local protocols that this server uses directly:
MQTT (port 8883, TLS): All printer commands and state reports flow over an MQTT broker running on the printer itself. Authentication uses username bblp and your LAN access code; the serial number identifies the device topics. Commands like starting a print, cancelling a job, and dispatching G-code lines are all MQTT publishes to the device topic. Status data is received by subscribing to the printer's report topic and requesting a push_all refresh. This implementation is based on community reverse engineering documented in the OpenBambuAPI project.
FTPS (port 990, implicit TLS): File operations (upload and directory listing) use FTPS. The printer's SD card is accessible as a filesystem with directories including cache/ (for 3MF and G-code print files), timelapse/, and logs/. Authentication uses the username bblp and your access token as the password.
What this fork fixes
This package works around two protocol-level issues in the underlying bambu-js library.
Bug 1: FTP double-path error in bambu-js.
The bambu-js library's sendFile method has a path construction bug. It calls ensureDir to change the working directory into the target directory (e.g., /cache), and then calls uploadFrom with the full relative path including the directory prefix (e.g., cache/file.3mf). The result is that the file lands at the wrong path on the printer (e.g., /cache/cache/file.3mf instead of /cache/file.3mf), and the subsequent print command fails because it references a file that does not exist at the expected path.
This fork bypasses bambu-js for all uploads and uses basic-ftp directly. The upload function (ftpUpload) connects to the printer, resolves the absolute remote path, changes to the correct directory with ensureDir, and then uploads using only the basename -- avoiding the double-path construction entirely.
Merge vertices that are closer together than the specified tolerance. This can close small gaps in a mesh and slightly reduce file size. Useful as a cleanup step before slicing.
tolerance is in millimeters and defaults to 0.01 if omitted.
center_model
Translate the model so the center of its bounding box sits at the world origin (0, 0, 0). Useful before applying transformations or exporting for use in another tool.
config.json
{
"stl_path": "/path/to/model.stl"
}
lay_flat
Identify the largest flat surface on the model and rotate the model so that face is oriented downward on the XY plane (Z = 0). This is a common preparation step before slicing to minimize the need for supports.
config.json
{
"stl_path": "/path/to/model.stl"
}
Note: this works best on models with a clearly dominant flat face. Results on organic or rounded shapes may be unpredictable.
Printer Control Tools
Printer Control Tools
All printer tools accept optional , , and arguments. If omitted, values fall back to the environment variables , , and . Passing them explicitly is useful when working with more than one printer.
Available Resources
Available Resources
Resources follow the MCP resource protocol and can be read by calling ReadResource with a URI. The server also lists them via ListResources.
Printer resources
printer://{host}/status -- Current printer status. Equivalent to calling get_printer_status. Returns a JSON object with temperature, progress, layer, AMS, and raw state data.
printer://{host}/files -- File listing for the printer's SD card. Equivalent to calling list_printer_files. Returns files grouped by directory.
printer://{host}/hms -- HMS and error diagnostics from the latest status payload. Returns connection state, printer status, explicit HMS payloads when present, and shallow raw fields whose names indicate errors, failures, warnings, or HMS data.
Example: To read the status of the default printer, use URI printer://192.168.1.100/status. The host segment must match a configured printer IP; the server uses PRINTER_HOST if the default URI template is used.
Bambu Lab Printer Limitations
Bambu Lab Printer Limitations
Understanding these constraints will help you avoid frustrating errors and set appropriate expectations.
Printable 3MF required for print_3mf. The print_3mf tool expects a sliced 3MF containing at least one Metadata/plate_<n>.gcode entry. If you pass an unsliced 3MF (one exported from a CAD tool without slicing), the server attempts auto-slicing. BambuStudio, FULU, and Orca CLI paths require the matching machine preset and complete profile preparation; any inspection or slicing failure stops before upload. For a previewable workflow, pre-slice in FULU OrcaSlicer-bambulab, OrcaSlicer, or Bambu Studio and pass the resulting .gcode.3mf. See slicing guide for the full procedure.
Layer height, temperature, and slicer settings are baked in. The project_file MQTT command tells the printer which plate to run. It does not support overriding layer height, temperature targets, infill percentage, or other slicing parameters at print time. These must be set in your slicer before generating the 3MF.
G-code and 3MF jobs use different command paths.start_print_job sends a GCodeFileCommand over MQTT and is intended only for plain G-code files stored in the cache/ directory. Sliced 3MF files must go through print_3mf, which selects the model-specific command and upload location. See the routing table. Mixing these up will result in the printer either ignoring the command or displaying an error.
Temperature commands depend on printer state.set_temperature dispatches M104 or M140 G-code via MQTT. Whether the printer accepts these commands depends on its current firmware version and operational state. Some printer states (such as the idle screen with AMS management open) may ignore or queue the commands.
Status and command submission are separate evidence. Local MQTT connections are reused and status is read from received printer reports. Reports can lag during startup, sleep, or state transitions. Inspect HMS errors and the printer's actual state after submitting a job; a tool's success response is not physical-print confirmation.
General Limitations and Considerations
General Limitations and Considerations
Memory usage
STL manipulation tools load the entire mesh into memory as Three.js geometry. For large files:
Files over 10 MB can consume several hundred MB of RAM during processing.
Running multiple operations sequentially on large files may cause memory to accumulate between garbage collection cycles.
If you encounter out-of-memory errors, try splitting large operations or working with smaller/simplified meshes.
The server has no built-in memory cap. On constrained systems, set the TEMP_DIR to a fast local path and avoid processing multiple large files concurrently.
STL manipulation limitations
lay_flat identifies the largest flat face by analyzing surface normals. It works reliably on mechanical parts with clear flat faces and less reliably on organic or curved models where no single dominant face exists.
extend_stl_base adds a new rectangular solid beneath the model. For models with complex or non-planar undersides, the result may include gaps or intersections at the join. Review the modified STL before printing.
merge_vertices uses a distance tolerance to identify near-duplicate vertices. Setting the tolerance too high can alter model geometry. The default of 0.01 mm is safe for most models.
Non-manifold meshes (meshes with holes, overlapping faces, or internal geometry) may produce unpredictable results for any transformation operation. Use a mesh repair tool (Meshmixer, PrusaSlicer's repair function, or Bambu Studio's repair option) before working with problematic files.
Performance considerations
Slicing with BambuStudio CLI can take 30 seconds to several minutes depending on model complexity, layer height, and your system's CPU. The slice_stl call is synchronous and will block until the slicer process completes.
FTPS uploads for large 3MF files (multi-plate prints, high-detail models) may take 15 to 60 seconds depending on your local network speed.
MQTT connections are pooled by host + serial key. The first call to any printer tool in a session establishes the MQTT connection; subsequent calls reuse it. If the connection drops (printer power cycled, network interruption), the next call will reconnect automatically.
Some printer command surfaces and workflow priorities were informed by Bambuddy, an AGPL-3.0 Bambu Lab printer management project. This project does not vendor Bambuddy code.
Metadata/plate_<n>.json
ams_mapping2
Auto-match AMS slots by RFID (auto_match_ams flag on print_3mf). Resolves required tray_info_idx from the sliced 3MF against live AMS inventory. Handles same-SKU different-color filaments by matching on (tray_info_idx, tray_color) and tracking already-claimed slots. Dry-run with resolve_3mf_ams_slots before printing.
Cancel, pause, and resume in-progress print jobs via MQTT
Skip specific objects during a running multi-object print via skip_objects (use list_3mf_plate_objects to find object IDs first)
Set print speed mode (silent/standard/sport/ludicrous), clear HMS/print errors, trigger AMS RFID re-read, and control H2/P2 airduct mode (cooling/heating) via MQTT
Start/stop AMS filament drying (set_ams_drying) on heated AMS units (AMS Pro / AMS-HT). Sends print.ams_control MQTT command.
Set nozzle and bed temperature via G-code dispatch over MQTT
Confirm print starts and positive manual heating through a human preflight prompt. Finished-bed clearance and hardware-error clearing require explicit human acknowledgment; see hardware safety and headless configuration.
Set fan speed (part, auxiliary, chamber) and chamber light mode (on/off/flashing) via MQTT
Read HMS (Health Management System) diagnostics as an MCP resource at printer://{host}/hms — read-only error summary from the printer, with automatic settle retry
Start G-code files already stored on the printer
Collar charm print wrapper (print_collar_charm) — specialized two-color workflow with fixed tray policy for inner (black, AMS 1 slot 1) and outer (white, AMS 2 slot 1) charm parts
STL manipulation: scale, rotate, extend base, merge vertices, center at origin, lay flat, and inspect model info
Slice STL or 3MF files using an external CLI, or use the optional orca-slicer-api backend in a separate container without a local slicer executable. Remote slicing requires a matching read-only Orca profile tree and currently supports one filament slot and one selected plate. BambuStudio, FULU, and Orca require the exact machine preset and resolve BBL dependencies before slicing; see FULU/Orca CLI setup and validation limits.
Inspect slicer settings from a saved 3MF template or extracted profile via get_slice_settings
Enumerate saved slicing templates from the local registry via list_templates
Save templates into the local registry via save_template
Slice directly from a named template via slice_with_template
For simple single-material slices, auto-select the printer's current or first loaded AMS filament when no explicit slicer profile or load_filaments override is provided
Template-driven slicing can reuse a saved 3MF's process settings while still pulling the live printer filament choice over MQTT
Optional Blender MCP bridge for advanced mesh operations
Dual transport: stdio (default, for Claude Desktop / Claude Code) and Streamable HTTP
Dual-nozzle printers (H2D, H2D Pro, H2C, X2D) have two external spool holders, and the printer reports one virtual slot per nozzle. Use Bambu Studio's ids in ams_slots/ams_mapping: 254 is the left/deputy nozzle's external spool and 255 the right/main nozzle's. The server composes the selected plate's filament_map with physical_extruder_map to verify each filament's physical nozzle (0 = right, 1 = left), and requires the matching fresh vir_slot report. An explicit external-spool mapping is preserved with use_ams: false; a missing mapping is derived only from these inspected headers. Single-nozzle printers keep 254 as their only external tray.
Auto-match AMS by RFID
For pre-sliced 3MFs that declare filament types, the auto_match_ams flag on print_3mf (or the standalone resolve_3mf_ams_slots dry-run tool) automatically resolves the required filaments against your live AMS inventory. The matcher works as follows:
Reads the required tray_info_idx values from the 3MF's Metadata/slice_info.config and Metadata/plate_<n>.json
Reads your live AMS trays from the printer's MQTT status push
Matches on (tray_info_idx, tray_color) — so two filaments of the same SKU but different colors (e.g. two GFG02 PETG HF spools in black and white) resolve to different slots
Tracks already-claimed slots so two requirements can't collapse onto the same physical position
Falls back to SKU-only matching when the 3MF carries no color data or only one tray of that SKU is loaded
If resolution fails, returns a structured missing report with per-requirement reasons:
no_loaded_match — no AMS tray of that SKU is loaded
color_mismatch — the SKU matches but the loaded color differs
exhausted — all matching trays are already claimed by other requirements
no_sku — the 3MF doesn't declare a tray_info_idx for this filament
Dry-run with resolve_3mf_ams_slots before printing to preview the match without uploading or starting a job.
AMS settle-time handling
The first MQTT status push from an idle printer is often sparse (model/module info only) — AMS slot data arrives on a second push. The server's filament inventory and HMS handlers both retry after a 1.5-second settle window when the expected data isn't present in the first response. This is transparent to the caller.
Checking AMS status
Use get_printer_filaments for the parsed, enriched view (profile paths, display names, match confidence) or get_printer_status for the raw AMS data from the printer:
Code
"What filaments are loaded in my AMS right now?"
Bug 2: AMS mapping format in the project_file MQTT command.
The bambu-js library's project file command hardcodes use_ams: true and does not support the ams_mapping field at all. Without the fix, the mapping is a simple array of slot indices (e.g., [0, 2]), which does not match the OpenBambuAPI specification.
For the non-H2/P2S project-file route, this implementation retains at least five positions in the ams_mapping array where position i is the project filament index and the value is the AMS slot feeding that filament. For example, a single-filament print from AMS slot 0 sends [0, -1, -1, -1, -1].
This fork sends the project_file command directly via bambu-node (bypassing bambu-js entirely for print initiation) and constructs the mapping in the format the target firmware expects:
The command payload also includes all required fields per the OpenBambuAPI spec: param (the internal gcode path within the 3MF), url (the sdcard path), md5 (computed from the plate's embedded gcode), and all calibration flags.
Verified print procedure (H2S, LAN-only, no client cert)
This is the sequence that successfully started a print on an H2S in the original LAN-only test. It's documented here because several common approaches fail on this firmware, and this fork's transport is what makes it reliable.
Result: print started in RUNNING state, printer accepted the MQTT project_file command, no client certificate was required. Authentication was plain bblp + LAN access code over TLS with rejectUnauthorized: false.
What doesn't work on stock bambu-cli:
bambu-cli print start <file> and bambu-cli files upload both fail with 522 SSL connection failed: session reuse required. Bambu's FTPS server requires TLS session reuse between the control and data channels, which the Go FTPS client in bambu-cli does not negotiate correctly.
bambu-cli print start --no-upload still opens an FTPS session (to stat the remote file) and hits the same 522.
What works — two-step upload + MQTT dispatch:
Upload the .gcode.3mf via curl (curl's OpenSSL backend negotiates FTPS session reuse correctly):
url must be ftp:///<filename> (three slashes) — the empty host component is required; the printer rejects ftp://<filename> as "unsupported print file path or name".
param uses the internal plate path inside the 3MF (Metadata/plate_1.gcode for plate 1), not a filesystem path.
md5: "" is accepted; populating it is optional.
On AMS-equipped H2 printers, use_ams: false does not suppress mapping lookup if the sliced file declares filaments. The working H2 path is to send use_ams: true plus a valid mapping. For H2, the mapping length must match the project-level filament declaration length, and the populated positions must match plate_<n>.json.filament_ids. Prefer ams_slots at the tool layer and let the server expand it. If no mapping is provided for an H2 pre-sliced job with declared filaments, the server fails before sending; pass explicit ams_slots, raw ams_mapping, or auto_match_ams: true.
No client X.509 certificate was needed. The earlier assumption that post-Jan 2025 firmware mandates mTLS on all models does not hold for the H2S in LAN mode — user/password over TLS is sufficient.
The MCP server's ftpUpload helper (basic-ftp with secure: "implicit" and a short idle timeout) performs the equivalent upload natively and is the preferred path when using the server itself; the curl form is the manual-debug equivalent.
host
bambu_serial
bambu_token
PRINTER_HOST
BAMBU_SERIAL
BAMBU_TOKEN
The server also accepts the alias variables BAMBU_PRINTER_HOST, BAMBU_PRINTER_SERIAL, and BAMBU_PRINTER_ACCESS_TOKEN, plus BAMBU_PRINTER_MODEL and BAMBU_STUDIO_PATH.
get_printer_status
Retrieve current printer state including temperatures, print progress, layer count, time remaining, and AMS slot data. Internally sends a push_all MQTT command to force a fresh status report before reading cached state.
Chamber status decodes the current temperature from newer firmware's packed CTC reports, including P2S, while retaining legacy chamber/frame fields.
Returns a structured object with fields including status (gcode_state string), temperatures.nozzle, temperatures.bed, temperatures.chamber, print.progress, print.currentLayer, print.totalLayers, print.timeRemaining, and ams (raw AMS data from the printer).
get_printer_filaments
Read the live AMS inventory and resolve each loaded tray to Bambu Studio
filament profile JSON paths when bambu_model is known. The result includes a
summary, per-slot display labels, profile match confidence, and a recommended
load_filaments value for simple single-material CLI slicing.
trays[].profile_resolution: exact-model-nozzle, model, generic, or
unresolved
trays[].match_confidence: high, medium, low, or none
recommended.load_filaments: the profile path the MCP will use for
auto-slicing when no explicit filament override is provided
list_printer_files
List files stored on the printer's SD card. Scans the cache/, timelapse/, and logs/ directories and returns both a flat list and a directory-grouped breakdown.
This is a read-only query: it never creates directories. Optional directories absent from a successful root listing return empty lists. Authentication, TLS, permission, and transfer failures are reported as errors rather than empty or partial results.
Capture a single JPEG frame from the printer's chamber camera. Read-only.
Two transports are wired in, picked by bambu_model:
TCP-on-6000 for A1, A1 mini, P1S, P1P. Native protocol per OpenBambuAPI/video.md: TLS on port 6000, 80-byte auth packet (bblp + access token), repeating 16-byte frame header + JPEG payload.
RTSP for X1, X1 Carbon, X1E, P2S, X2D and H2, H2S, H2D, H2C, H2D Pro. Shells out to ffmpeg with rtsps://bblp:<token>@<host>:322/streaming/live/1 -frames:v 1. The H2 series wasn't documented in OpenBambuAPI's video.md but its firmware uses the same RTSP endpoint as X1 (verified live against an H2S, 2026-04-27).
Requires ffmpeg in PATH for the RTSP path. Install with brew install ffmpeg on macOS. Configure a trusted custom binary with the server-side FFMPEG_PATH environment variable, or set MCP_ALLOW_EXECUTABLE_ARG=1 before using the ffmpeg_path tool argument. The TCP-on-6000 path uses native Node TLS and does not require ffmpeg.
Returns { status, format: "image/jpeg", sizeBytes, base64, savedTo?, transport }. transport is "tcp-6000" or "rtsps-322" so callers can tell which path produced the frame. Pass save_path to also write the bytes to disk; otherwise only the base64 payload is returned.
delete_printer_file
Delete a single file from the printer's SD card via FTPS. Destructive. Requires confirm: true — without it the call returns status: "skipped" and does not contact the printer. Path traversal segments (..) are rejected. Only files under cache/, timelapse/, and logs/ can be deleted.
Upload a local file (G-code or 3MF) to the printer. If print is true and the file is a .gcode file, start_print_job is called automatically after a successful upload. For .3mf files, upload completes normally but you must use print_3mf to initiate the print (which handles plate selection and metadata).
Start printing a .gcode file that is already on the printer's SD card. Do not use this for .3mf files -- use print_3mf instead, which handles the project_file MQTT command with proper metadata.
If filename does not include a directory prefix, the server prepends cache/ automatically.
cancel_print
Cancel the currently running print job. Sends an UpdateState MQTT command with state: "stop". Not resumable — use pause_print if you may want to continue.
Set a checked target temperature for the bed or nozzle through MQTT. Positive targets require the printer model and fresh matching printer telemetry; nozzle heating also requires the declared loaded material and matching nozzle_diameter (default 0.4). Independent model/component and material ceilings apply. A target of zero turns the heater off without requiring material or nozzle metadata. Accepted component values are bed, nozzle, extruder, tool, and tool0.
Manual nozzle heating checks the reported currently loaded AMS tray or external spool. It refuses ambiguous active-nozzle/material selection on multi-nozzle printers; use a checked sliced job or the printer's own controls there. Stop and heater-off commands cancel pending server print/heating operations. Resuming through MCP requires the same paused job inspected and started by this server instance, with fresh matching telemetry; other paused jobs remain controllable at the printer.
Start or stop the AMS filament drying cycle on heated AMS units (AMS Pro / AMS-HT). The action parameter accepts start or stop. The ams_id must be an integer from 0 to 3.
Inspect a prepared sliced 3MF or textual G-code file offline before deciding what to export or print. This tool copies the file into a private read-only snapshot and reuses the same archive, selected-plate, model/nozzle/material and temperature checks used by print preflight. It never contacts a printer or auto-slices an unsliced project.
file_path and explicit bambu_model are required; the model is never inferred from configuration. plate_index is zero-based and defaults to 0. Nozzle/bed checks are optional comparisons against file declarations, not observations of installed hardware. Only these five argument names are accepted; credentials, host and executable/bridge overrides are not part of this tool.
The generic result has receipt_version: "1", evidence: "file-only", dispatch_authorized: false, artifact (sha256, byte_length, file_format), the requested selection, and the original inspection including declared model, nozzles, materials/used filament positions, internal plate path and checked temperature peaks. Hash and byte length identify the exact inspected snapshot; a consumer must compare them with its own artifact and selected plate. The temporary snapshot is removed, and its path is not a dispatch capability. The receipt does not prove printer readiness, physical material/nozzle contents, fit, full motion simulation or permission to print. Actual print routes still independently inspect the dispatched snapshot and require fresh hardware state and human preflight.
print_3mf
The primary tool for starting a Bambu print. Recommended input: a pre-sliced .gcode.3mf exported from FULU OrcaSlicer-bambulab, OrcaSlicer, or Bambu Studio — see slicing guide. This tool handles the complete workflow:
Checks whether the 3MF contains embedded G-code (Metadata/plate_<n>.gcode entries).
If no G-code is found, attempts to auto-slice via the configured slicer. Profile preparation or slicing failures stop the operation before upload. See the slicing guide for tested CLI versions and combinations.
Parses the sliced 3MF to extract the correct plate file and compute its MD5 hash.
Reads slicer metadata and any explicit AMS selection to build the filament mapping.
Uploads via basic-ftp to the model-specific location: SD root for H2/full-size A1, cache/ for P1/X1/A1 mini/P2S. X2D print_3mf instead uses its checked native eMMC route on macOS or Linux.
Sends the correct MQTT print command for the target printer family. For H2S/H2D/H2C that means project_file with project-length ams_mapping, parallel ams_mapping2, and H2-compatible calibration flags.
bambu_model is required for model-specific routing and preset selection. It does not by itself validate pre-sliced G-code. BambuStudio, FULU, and Orca CLI preparation additionally require the exact model/nozzle machine preset and reject incomplete profiles. Using the wrong model can damage hardware. If bambu_model is not provided in the tool call and BAMBU_MODEL is not set in the environment, the server will ask you interactively via MCP elicitation (if your client supports it) or return a clear error.
bed_type defaults to textured_plate if omitted. nozzle_type (stainless_steel, hardened_steel, tungsten_carbide, brass; default BAMBU_NOZZLE_TYPE) sets the installed nozzle when the project must be auto-sliced; the job's nozzle type must match the printer's report, and stock P1S/P1P/A1 presets assume stainless steel. nozzle_volume_type (standard, high_flow; default BAMBU_NOZZLE_VOLUME_TYPE) likewise sets the installed nozzle's flow type for auto-slicing; it must match the printer's reported nozzle flow. After an MQTT print command the server listens to the printer's pushed reports for up to 15 seconds (BAMBU_DISPATCH_CHECK_MS) and returns dispatch: "started" or "unconfirmed"; if firmware 01.08.05+ refuses the command (HMS 0500-0500-0001-0007, needs LAN Only Mode and Developer Mode), the call fails and says so; clear that fatal HMS entry with clear_hms_errors before printing again. ams_slots is the preferred override input; ams_mapping remains the raw escape hatch. On AMS-equipped H2 printers, use_ams: false does not suppress mapping lookup if the sliced file declares filaments. If no mapping is provided for an H2 pre-sliced job with declared filaments, the server fails before sending; pass explicit ams_slots, raw ams_mapping, or auto_match_ams: true.
Set auto_match_ams: true to match the sliced 3MF's tray_info_idx values against the live AMS inventory and use the matching ams_slots. The matcher joins on (tray_info_idx, tray_color) and tracks already-claimed slots, so prints with two filaments of the same SKU but different colors (e.g. two GFG02 PETG HF in black and white) resolve correctly. Falls back to SKU-only when the 3MF's filament has no color set or only one tray of that SKU is loaded. Returns a structured missing report (reason: "no_loaded_match" | "color_mismatch" | "exhausted" | "no_sku") when a filament can't be resolved. Ignored when you provide ams_slots or ams_mapping explicitly.
Layer height, nozzle temperature, and other slicer parameters cannot be overridden via this tool -- they are baked into the 3MF's G-code at slice time. Apply those settings in your slicer before generating the 3MF.
For the optional FULU bridge, set connection_mode: "bambu_network" and explicitly choose connection_type: "cloud" or "lan"; see FULU setup. A successful command submission is not proof that the printer accepted it: inspect printer state, HMS errors, and the printer itself.
bambu_network_bridge_status
Inspect the configured FULU bridge without starting it using {}. Use {"connect": true} to launch the host, handshake, and initialize an agent. See bridge probes for interpreting the result.
bambu_network_call
Call an allowed read-only probe such as {"method": "net.is_user_login", "payload": {}}. The default injects the initialized agent; use with_agent: false for bridge.handshake. Raw printer mutations and unknown methods are refused; use the dedicated checked print or printer tools.
X2D native transport (macOS)
Install Bambu Studio and its networking plug-in, plus the Apple command-line developer tools (clang++). The plug-in is loaded at runtime and is not redistributed. In the installed bambu-printer-mcp package directory, run npm run build:native. For a global install, locate that directory with npm root -g; for an extracted desktop extension, run the same command in the extension directory. Rebuild after updating the package. For Linux, see X2D native transport (Linux); Windows can use status and slicing only.
The npm package and desktop bundle include native/bambu-native-print.cpp, scripts/build-bambu-native.sh and the Linux setup script, never a developer's compiled binary. The server finds the built helper relative to its installed package, regardless of the launch directory. A trusted server setting BAMBU_NATIVE_HELPER can select an alternate executable.
For X2D, print_3mf defaults to connection_mode: "bambu_native"; legacy lan_mqtt_ftps requests are redirected to it. Supply ams_slots, a complete project-level ams_mapping, or auto_match_ams: true. A job that uses only one external spool requires explicit use_ams: false; a job mixing AMS trays with the external spools maps them as 254 (left/deputy nozzle) and 255 (right/main nozzle). Raw ams_mapping2 and nozzle/extra-option overrides are rejected before dispatch; the server derives both AMS representations from the checked structured mapping. Model/nozzle/material inspection, fresh printer-state checks, and human preflight apply before the helper receives a private snapshot. The native helper requests fresh shared printer-state authorization immediately before each print submission, including a certificate retry, and before checked heating, resume, or error-clearing commands; custom helpers must support this handshake. Stop and heater-off remain available without preflight. Native upload-only requests use the same all-plate inspection as FTPS uploads. They accept project_name, preset_name, bed_type, and an existing plate_index; AMS, nozzle, and calibration print options are rejected. Use print_3mf for checked print settings.
The helper waits for connection/certificate exchange and retries only the initial -4030 send once. Rebuild the helper after upgrading to receive the teardown fix. A successful dispatch receipt ends the helper before plug-in cleanup can turn an accepted job into an error. If an older/custom helper crashes after dispatch, the server reports uncertainty: check the printer state and job name before retrying, because resending can duplicate a print. Previous hardware testing reached RUNNING on X2D; this revision is validated with mocked transport regressions and clean installs, not a new physical print. bambu_connect is an optional macOS handoff for user review in Bambu Connect and does not start a print. Native task, heater, and error controls retain the common safety checks; raw controls cannot bypass them. Request cancellation, stop, and heater-off interrupt pending native helpers; the server waits for process exit before releasing a checked file. A command already sent to the printer cannot be recalled by cancelling the request, so verify printer state before retrying.
X2D native transport (Linux)
On x86-64 Linux, one command builds the helper and installs Bambu's networking plug-in and the Bambu Studio certificates. It needs a C++ compiler (g++ or clang++) and network access; no desktop or slicer is required:
Use the same package version as the server, for example bambu-printer-mcp@1.2.3; when the installation is missing or stale, the server's error names the exact command. The setup downloads the Linux plug-in that Bambu Studio itself installs, pinned to an exact version and SHA-256, and stores it with the certificates under ~/.config/bambu-printer-mcp/bambu-native (BAMBU_NATIVE_HOME or XDG_CONFIG_HOME move it; set the same value for the server). The plug-in is not redistributed by this package, and Bambu Studio's own auto-updating copy is never used. The server finds the installation automatically and passes the plug-in and certificate paths to the helper. Rerun the setup with the server's package version after upgrading: the server refuses a helper built from another version. Only missing or changed files are downloaded again. The setup then loads the plug-in once, offline, so missing system libraries are reported during installation rather than on a stop command. --verify repeats these checks without network access. On Linux the server uses only this managed helper or BAMBU_NATIVE_HELPER; a package-local npm run build:native binary is not used.
--check-update asks Bambu's plug-in service for the newest Linux plug-in and compares the PrintParams layout in the matching Bambu Studio header with the helper. It reports only: the setup never installs an unpinned plug-in, because a changed layout would send wrong print parameters. A pin is raised by a package release after the check passes and a hardware test.
Once the helper, plug-in and certificates are installed, X2D printing, upload and controls use the same routing, safety checks and authorization handshake described for macOS above. On Linux, stop and heater-off go out over the native route and MQTT at the same time, so a stuck helper cannot delay them. MQTT is sent again once every older print or heating helper for that printer has exited and the immediate MQTT attempt has settled, so none can dispatch after it; either the native route or that later MQTT send succeeding counts, and the result lists all sends under routes. Each MQTT send gives up after 15 seconds (BAMBU_EMERGENCY_MQTT_TIMEOUT_MS), so an unreachable MQTT connection cannot hold back a stop the native route already sent. A connection completing after that deadline cannot dispatch its expired command; an already queued MQTT publish is discarded by force-closing and invalidating that client. A repeated stop or heater-off is harmless. macOS keeps its native-only route. The server accepts only the pinned plug-in checksums; BAMBU_NATIVE_ALLOW_UNPINNED_PLUGIN=1 is a trusted override for testing another build at your own risk. Without a complete installation, Linux keeps its previous behavior: X2D status and slicing work, stop, pause and heater-off use MQTT, and native print requests name the setup command before contacting the printer. Bambu publishes the Linux plug-in for x86-64 only; other architectures keep the MQTT behavior.
x2d_native_control
This optional X2D metadata tool accepts ams_filament_setting and extrusion_cali_sel, plus the read-only queries extrusion_cali_get, extrusion_cali_get_result, and flowrate_get_result. It validates command fields, numeric metadata, and AMS unit/slot selection. Motion, filament loading, heating, safety-setting changes, and task control are not exposed through raw JSON; use the dedicated checked tools where available. A metadata declaration does not verify the physical spool contents.
print_3mf_bambu_network
Submit a sliced project through FULU's separately configured networking runtime. connection_type defaults to cloud. Both cloud and LAN bridge jobs require a printer IP, LAN access code, matching serial/device ID, and fresh MQTT safety telemetry. File, raw AMS/nozzle mapping, and extra-option overrides cannot replace checked parameters. See print examples and AMS requirements. A zero bridge return code confirms submission, not a physical print or direct X2D support.
resolve_3mf_ams_slots
Dry-run the AMS match without uploading or starting a print. The tool reads Metadata/plate_<n>.json and Metadata/slice_info.config, then compares required tray_info_idx values against live AMS trays.
High-level wrapper for a prepared two-part dog-collar-charm workflow. This tool is intentionally specialized: it expects a prepared two-part charm project and applies a fixed tray policy.
Smaller inner object -> black -> AMS 1 slot 1
Larger outer object -> white -> AMS 2 slot 1
The tool will:
Resolve a local .3mf or template_name.
Auto-slice if the 3MF is still an unsliced project.
Inspect Metadata/plate_1.json to identify the smaller inner part and larger outer part.
Preflight the required AMS trays on the printer.
Dispatch the print through the existing H2-safe print3mf path using ams_slots.
You can also pass source_path directly instead of template_name.
This wrapper currently assumes:
the input is a prepared two-part charm .3mf, not a bare STL that needs color-region generation
the selected plate has exactly 2 objects
the selected plate has exactly 2 used filament positions
the smaller object is the inner insert/letter and the larger object is the outer body
If the project does not match those assumptions, the tool fails fast with a structured error instead of guessing. The role-to-color and color-to-tray mapping is isolated in code so the next version can evolve toward customer-requested colors without replacing the whole wrapper.
Slicing Tools
Slicing Tools
Note: the verified workflow is to slice in Bambu Studio (GUI) and feed the resulting .gcode.3mf to print_3mf. The CLI-driven slicing tools below (slice_stl, slice_with_template) work but are sensitive to profile drift and are not the recommended path for production prints. See slicing guide.
list_templates
List saved templates from the local registry directory. You can override the registry root with BAMBU_TEMPLATE_DIR.
config.json
{}
Each result includes the template name, absolute path, source type, and relative path inside the registry. You can then pass template_name to get_slice_settings, slice_stl, or print_3mf instead of a raw path.
save_template
Copy a local 3mf, json, or .config file into the template registry and register it under a reusable template name.
This creates the destination under the template registry directory and makes it available immediately to list_templates, get_slice_settings, slice_with_template, slice_stl, and print_3mf.
get_slice_settings
Inspect the slicer settings embedded in a saved 3MF template or in an extracted JSON/config profile without slicing anything.
config.json
{
"template_name": "h2s_template"
}
This returns a compact summary of the high-signal settings such as printer preset, default print profile, filament profiles, layer height, infill density, shell counts, support mode, and bed type. It accepts either source_path or template_name. For 3MF inputs it also writes the extracted settings blob to a temp path so the result can be reused directly.
slice_with_template
Slice an STL or 3MF using a named template from the local registry. This is a higher-level wrapper over slice_stl for template-based workflows.
This uses the named template as the slicing profile source and still supports live printer filament selection unless you explicitly override load_filaments. The template settings are applied at slice time, and the later print_3mf step computes H2-safe AMS mapping from the newly sliced output.
slice_stl
Slice an STL or 3MF file using an external slicer and return the path to the output file. The output is a sliced 3MF (for BambuStudio, OrcaSlicer, and FULU OrcaSlicer-bambulab) or a G-code file (for PrusaSlicer, Cura, Slic3r).
slicer_type options: bambustudio, orcaslicer, orcaslicer-bambulab (FULU), prusaslicer, cura, slic3r. Aliases include fulu-orca and orca-studio. When omitted, the value from the SLICER_TYPE environment variable is used (default: bambustudio).
FULU/Orca CLI safety: from 1.1.11, these backends require the exact model/nozzle preset from the selected installation and stop on profile preparation failures. A process override cannot bypass that gate. See configuration and validation limits.
slicer_path and slicer_profile fall back to the SLICER_PATH and SLICER_PROFILE environment variables when omitted. Per-call slicer_path overrides require MCP_ALLOW_EXECUTABLE_ARG=1.
You can provide either template_3mf_path or template_name when you want to slice from a saved template. template_name resolves through the local template registry directory configured for the server.
For printing on a Bambu printer, the recommended workflow is: export a sliced 3MF from your selected Bambu-compatible slicer, then pass that output path to print_3mf.
BambuStudio Slicer Options
When slicer_type is bambustudio (the default), these additional parameters are available on slice_stl:
Parameter
Type
Description
uptodate
boolean
Update 3MF configs to latest BambuStudio presets
repetitions
number
Number of copies to print
orient
boolean
Auto-orient model for optimal printability
arrange
boolean
Auto-arrange objects on the build plate
ensure_on_bed
boolean
Lift floating models onto the bed
clone_objects
string
Clone counts per object, comma-separated (e.g. "1,3,1,10")
skip_objects
string
Object indices to skip, comma-separated (e.g. "3,5,10")
load_filaments
string
Filament profile paths, semicolon-separated
load_filament_ids
string
Filament-to-object mapping, comma-separated
nozzle_volume_type
string
Installed nozzle flow type: standard or high_flow (default: BAMBU_NOZZLE_VOLUME_TYPE, else the preset's Standard default). high_flow uses the presets' High Flow values, such as the filament's High Flow max volumetric speed, and is refused if the machine preset declares no High Flow variant. Also on slice_with_template.
filament_colours
string
Slot colours, one #RRGGBB per filament slot, semicolon-separated. Explicit values take priority, followed by input 3MF colours, each custom profile's colour, then the BambuStudio default.
When print_3mf detects an unsliced 3MF and auto-slices it, these defaults are applied automatically:
uptodate: true -- prevents stale config bugs from downloaded 3MFs
ensure_on_bed: true -- safety net, lifts floating models onto the bed
min_save: true -- smaller output for faster FTP uploads to the printer
skip_modified_gcodes: true -- strips custom gcodes from other users' profiles
These defaults reduce stale-profile problems; inspect downloaded models and their slice preview before printing. When calling slice_stl directly, you have full control over every flag.
Advanced Tools
Advanced Tools
Blender MCP
Use a standard stdio Blender MCP server with BLENDER_MCP_COMMAND and
BLENDER_MCP_ARGS. For the common Blender MCP server, install uv and its
matching Blender addon, enable the addon, and start its connection inside
Blender. Set the command to your full uvx path and the argument array to
["blender-mcp"]. The Claude Desktop extension also offers these two optional
settings. Printer tools work without Blender configured.
Call blender_mcp_status with {"connect": true} to initialize the server
and discover its tools and input schemas. A connected MCP server does not
by itself prove that the Blender addon is running.
Call blender_mcp_call with a discovered tool name and its arguments. The
full MCP result, including images and errors, is returned. For example:
config.json
{
"tool_name": "get_scene_info",
"arguments": {"user_prompt": "Inspect the scene before preparing a print."}
}
For advanced Blender operations, forward execute_blender_code with code
and the user's original user_prompt. These calls may edit the active scene.
Use the discovered schema rather than assuming a tool exists.
blender_mcp_edit_model
The standard MCP edit helper imports an STL, applies ordered edits, and exports
an STL without replacing the input or an existing output. Supported operations
are decimate:<ratio> (greater than 0 through 1), remesh:<voxel size> (positive,
in STL coordinate units), and boolean_union:<STL path>. Other operations can
use blender_mcp_call. Both processes must have access to the same file paths.
When BLENDER_MCP_COMMAND selects standard MCP, the advertised tool schema
requires an explicit output_path for both preview and execution. Legacy-only
bridge configurations keep output_path optional for compatibility.
config.json
{
"stl_path": "/path/to/model.stl",
"output_path": "/path/to/model-edited.stl",
"operations": ["decimate:0.5"],
"user_prompt": "Reduce the triangle count of this model for printing.",
"execute": false
}
The default preview returns the plan and generated Python without launching
Blender. Set execute to true to run it. A successful standard edit returns
output_verified: true, output_path, byte count, and triangle count after
checking the matching export receipt and a valid finite mesh. The helper
preserves existing scene objects and requires Object Mode. Inspect the result
before slicing; a valid STL is not a guarantee of printability.
The bridge enforces request deadlines, closes child connections, and never
replays interrupted editing requests. After a timeout, inspect Blender before
trying the edit again because execution may already have started.
Existing custom executables still work through BLENDER_MCP_BRIDGE_COMMAND.
They receive MCP_BLENDER_PAYLOAD with the requested file and operations;
their results explicitly report output_verified: false. A missing executable
configuration is an error when execution is requested. Per-call legacy
bridge_command overrides remain disabled unless MCP_ALLOW_EXECUTABLE_ARG=1.
Only hidden or informational HMS entries let an operation proceed. Fatal, serious and common HMS entries block printing, heating and resume. The exceptions are info-level entries and serious or common entries that Bambu lists for the exact printer model with empty text: the printer screen, Bambu Studio and Bambu Handy never show those, and the printer keeps printing with them. An X2D, for example, raises the hidden camera code HMS 0500-0600-0002-0070 at every boot. The list comes from the bundled HMS tables of a pinned Bambu Studio commit (scripts/generate-hidden-hms.mjs), selected by the printer's serial prefix as Bambu Studio does, and covers X2D, P2S, H2D, H2D Pro, H2S and H2C. Each model's own table decides: 0500-0600-0002-0070 is hidden in the X2D table, but the P2S table does not list it, so it still blocks a P2S. If Bambu later publishes text for a listed code, the gate keeps passing it until the list is regenerated from a newer Studio release. The print preflight names any hidden entry it passes, and the first check that passes each one logs it on stderr, so headless runs still record it. clear_hms_errors leaves hidden entries alone. Unlisted codes and other models' tables never qualify.
Network requirements depend on the path. Direct MQTT/FTPS tools require local reachability and compatible LAN/Developer Mode settings. FULU bridge cloud jobs use BambuNetwork and require its runtime, internet access, and authentication. Standard status, camera, file, and control tools remain local; bridge printing does not turn them into cloud tools.
Self-signed TLS certificate. The printer's FTPS server uses a self-signed certificate. The basic-ftp client is configured with rejectUnauthorized: false to accept it. This is standard for local network Bambu connections but assumes a trusted local network environment.
