Bambu Lab MCP Server

Model Context Protocol server for Bambu Lab 3D printers

Full control of Bambu Lab printers through Claude AI — MQTT, FTP, camera, AMS, and X.509 auth

Features · Quick Start · Tools · Background

Overview

Complete MCP server for Bambu Lab 3D printers (P1P, P1S, X1C, A1, A1 Mini). Connects over local MQTT for real-time control and monitoring, with FTPS file upload and X.509 certificate signing to bypass firmware authentication restrictions.

25 tools covering print control, status monitoring, camera, AMS filament management, temperature, LED control, and more.

Background

In January 2025, Bambu Lab pushed firmware updates requiring authentication for local LAN printer control, breaking all third-party tools — OctoPrint, Home Assistant integrations, custom scripts, everything.

Community researchers extracted the X.509 certificate and private key from the Bambu Connect desktop application, restoring third-party access. This MCP server builds on that work to provide comprehensive printer control through Claude.

Key references:

Hackaday: Bambu Connect's Authentication X.509 Certificate and Private Key Extracted — the article that started the workaround
OpenBambuAPI — reverse-engineered MQTT protocol documentation
bambu-node — TypeScript library for Bambu printers

Features

Local MQTT control — Print, pause, resume, stop, speed profiles, G-code execution
Real-time status — Continuous caching from MQTT reports with cached + fresh status tools
Camera control — Start/stop recording and timelapse
AMS management — Change filament trays, unload filament
FTP file upload — FTPS upload to printer SD card (port 990)
X.509 signing — Bypass firmware auth restrictions with certificate signing
Temperature control — Set nozzle/bed temps with safety limits
Object skipping — Skip failed objects without stopping the print
Speed profiles — Silent, Standard, Sport, Ludicrous (or raw percentage)
LED control — Chamber and work lights
Safety validation — Blocked G-codes, temperature limits, path traversal prevention

Quick Start

Prerequisites

Node.js 18+
Bambu Lab printer on your local network
Developer Mode enabled on the printer (recommended — Settings > LAN Only > Developer Mode)

Install

git clone https://github.com/schwarztim/bambu-mcp.git
cd bambu-mcp
npm install
npm run build

Option A: Developer Mode (Recommended)

Enable Developer Mode on your printer, then configure with your LAN credentials:

# Grab these from your printer screen:
#   IP Address:    WLAN → IP
#   Access Code:   WLAN → Access Code (8-digit)
#   Serial Number: Settings → Device → Serial Number

Add to ~/.claude/user-mcps.json:

{
  "mcpServers": {
    "bambu-lab": {
      "command": "node",
      "args": ["/path/to/bambu-mcp/dist/index.js"],
      "env": {
        "BAMBU_LAB_MQTT_HOST": "192.168.1.100",
        "BAMBU_LAB_MQTT_PASSWORD": "YOUR_ACCESS_CODE",
        "BAMBU_LAB_DEVICE_ID": "YOUR_SERIAL_NUMBER"
      }
    }
  }
}

Developer Mode gives the most reliable experience. All MQTT commands are automatically signed with X.509 certificates.

Option B: Browser Login (No Developer Mode)

If you don't want to enable Developer Mode (e.g., to keep Bambu Handy working), you can authenticate via browser login instead:

npm run setup

This opens Firefox (used instead of Chrome to avoid Google SSO bot detection), lets you log into your Bambu Lab account, and auto-discovers your printers. Credentials are saved to ~/.bambu-mcp/credentials.json and loaded automatically — no env vars needed.

Note: Token is valid for ~3 months. Run npm run setup again to refresh.

Then register with Claude Code (no env vars required):

{
  "mcpServers": {
    "bambu-lab": {
      "command": "node",
      "args": ["/path/to/bambu-mcp/dist/index.js"]
    }
  }
}

Limitations without Developer Mode: Printing .3mf files via project_file command requires Developer Mode. .gcode files and all other commands (stop, pause, resume, status, speed, G-code, camera, AMS) work without it.

Tools

Cloud API (4 tools)

Tool	Description
`get_user_profile`	Get Bambu Lab cloud account profile
`list_printers`	List all printers registered to cloud account
`get_printer_status`	Get printer status via cloud API
`sign_message`	Sign message with X.509 certificate for firmware auth bypass

Print Control (7 tools)

Tool	Description
`printer_stop`	Stop the current print immediately
`printer_pause`	Pause the current print
`printer_resume`	Resume a paused print
`printer_set_speed`	Set speed via profile (silent/standard/sport/ludicrous) or percentage
`printer_send_gcode`	Send G-code command (dangerous commands blocked)
`printer_print_file`	Start printing a file from printer SD card
`skip_objects`	Skip specific objects during multi-object prints

Status & Info (3 tools)

Tool	Description
`printer_get_status`	Request full status push (temps, progress, AMS, fans, etc.)
`printer_get_cached_status`	Return last cached status (no pushall — use for frequent polling)
`printer_get_version`	Get firmware and module version info

Camera (2 tools)

Tool	Description
`camera_record`	Enable/disable camera recording
`camera_timelapse`	Enable/disable timelapse recording

AMS & Filament (2 tools)

Tool	Description
`ams_change_filament`	Change to a different AMS tray (0-3)
`ams_unload_filament`	Unload current filament from extruder

Hardware (3 tools)

Tool	Description
`set_temperature`	Set nozzle or bed temperature (with safety limits)
`set_nozzle`	Set nozzle diameter for profile selection
`led_control`	Control chamber/work LED lights

Connection & Upload (3 tools)

Tool	Description
`mqtt_connect`	Connect to printer via local MQTT over TLS
`mqtt_disconnect`	Disconnect from MQTT
`ftp_upload_file`	Upload .gcode/.3mf/.stl to printer via FTPS

Architecture

Claude Code / AI
    |
    v
Bambu Lab MCP Server
  |-- Cloud API (bambulab.com)
  |-- MQTT Client (port 8883, TLS)
  |-- FTP Client (port 990, FTPS)
    |
    v
Bambu Lab Printer (P1P/P1S/X1C/A1)

How It Works

MQTT connects to the printer over TLS on port 8883 using the LAN access code
Status reports are continuously cached as they arrive on the MQTT report topic
Commands are sent on the MQTT request topic with sequence IDs for response matching
FTP uploads files to the printer SD card over FTPS (port 990)
X.509 signing uses the extracted Bambu Connect certificate for authenticated commands

Configuration

Environment Variables

Variable	Required	Description
`BAMBU_LAB_MQTT_HOST`	For MQTT	Printer IP address
`BAMBU_LAB_MQTT_PASSWORD`	For MQTT	LAN access code
`BAMBU_LAB_DEVICE_ID`	For MQTT	Printer serial number
`BAMBU_LAB_MQTT_PORT`	No	MQTT port (default: 8883)
`BAMBU_LAB_MQTT_USERNAME`	No	MQTT username (default: bblp)
`BAMBU_LAB_COOKIES`	For cloud	Session cookies for cloud API
`BAMBU_LAB_BASE_URL`	No	Cloud API base URL
`BAMBU_LAB_USER_ID`	No	Bambu Lab numeric user ID (for signed MQTT commands)
`BAMBU_LAB_APP_CERT_ID`	No	Override the built-in X.509 cert ID
`BAMBU_APP_PRIVATE_KEY`	No	Override the built-in X.509 private key
`BAMBU_APP_CERTIFICATE`	No	Override the built-in X.509 certificate

Finding Your Printer Info

IP Address: Printer screen → WLAN → IP
Access Code: Printer screen → WLAN → Access Code (8-digit)
Serial Number: Settings → Device → Serial Number

Security

X.509 Certificate

This server includes the publicly extracted X.509 certificate from the Bambu Connect desktop application. This is not a secret — it was publicly disclosed in January 2025 and is embedded in every copy of Bambu Connect.

All MQTT commands are now automatically signed with RSA-SHA256 using this certificate. This is required by post-January 2025 firmware — unsigned commands are rejected with error 84033543. No Developer Mode required for basic commands (stop, pause, resume, speed, G-code).

The certificate can be overridden via BAMBU_APP_PRIVATE_KEY and BAMBU_APP_CERTIFICATE environment variables if Bambu Lab rotates credentials. Set BAMBU_LAB_USER_ID (your numeric Bambu Lab user ID) for full compatibility — find it via the cloud API's /v1/design-user-service/my/preference endpoint.

Safety Features

Blocked G-codes: M112 (emergency stop), M502 (factory reset), M500/M501 (EEPROM), M997 (firmware update), M999 (restart)
Temperature limits: Nozzle max 300C, bed max 120C
File validation: Only .gcode, .3mf, .stl uploads allowed
Path traversal prevention: No .. or absolute paths in FTP uploads

Best Practices

Keep printers on a separate VLAN
Rotate LAN access codes periodically
Never commit .env files (already in .gitignore)

Acknowledgments

Community researchers who extracted the X.509 certificate — making this possible
OpenBambuAPI — reverse-engineered MQTT protocol docs
Shockedrope/bambu-mcp-server — speed profile concept
DMontgomery40/mcp-3D-printer-server — multi-printer platform inspiration
bambu-node — TypeScript Bambu library
Bambu Lab — for making excellent printers (even if the auth lockdown was rough)

License

MIT — see LICENSE for details.

Disclaimer

Not affiliated with or endorsed by Bambu Lab. Use at your own risk.

Name		Name	Last commit message	Last commit date
Latest commit History 17 Commits
.github		.github
api		api
docs		docs
scripts		scripts
src		src
.dockerignore		.dockerignore
.env.example		.env.example
.gitignore		.gitignore
Dockerfile		Dockerfile
LICENSE		LICENSE
README.md		README.md
launch-secure.sh		launch-secure.sh
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json

Folders and files

Latest commit

History

Repository files navigation

Bambu Lab MCP Server

Overview

Background

Features

Quick Start

Prerequisites

Install

Option A: Developer Mode (Recommended)

Option B: Browser Login (No Developer Mode)

Tools

Cloud API (4 tools)

Print Control (7 tools)

Status & Info (3 tools)

Camera (2 tools)

AMS & Filament (2 tools)

Hardware (3 tools)

Connection & Upload (3 tools)

Architecture

How It Works

Configuration

Environment Variables

Finding Your Printer Info

Security

X.509 Certificate

Safety Features

Best Practices

Acknowledgments

License

Disclaimer

About

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Uh oh!

Uh oh!

Contributors

Uh oh!

Languages

Packages