Bambu Lab CLI for slicing and printing 3D models

Developer voska released bambu, an open-source command-line tool that slices, sends and monitors Bambu Lab 3D prints over a local network without a cloud account or Bambu Connect. The tool drives the Bambu Studio CLI with printer-specific presets, gates `print send` behind a `--confirm` flag and preflight checks, and requires a printer in LAN Only mode with Developer Mode enabled, which Bambu Lab's January 2025 "Authorization Control" firmware made necessary for unsigned third-party control commands. It ships as a single static binary for macOS, Linux and Windows, offers `--json` output and stable exit codes for AI agents, and is tested only on the X1 Carbon, with the X1/X1E/P1/A1/H2/P2S series expected to work but untested.

Migrating the Python Print Operator? See the command and configuration guide https://github.com/voska/bambu/blob/main/docs/operator-migration.md . Slice, check, send and monitor Bambu Lab prints from the terminal over your LAN. It's built for humans and for AI agents. - Headless slicing: it drives the Bambu Studio CLI with the correct system presets for your printer and nozzle, plus recipes and --set overrides. - Safety first: - Preflight gates check that the printer is idle, the right filament is in the slot, the plate and nozzle match, Developer Mode is on, and there's enough filament. - print send refuses to run without --confirm . - No command ever changes printer settings. - LAN only: MQTT and FTPS go directly to the printer. No cloud account, no Bambu Connect. - Agent-friendly: --json everywhere NDJSON for streams , stable exit codes, schema introspection, and no prompts with --no-input . - Single static binary for macOS, Linux and Windows. bash $ bambu status workshop 192.168.1.50 IDLE / idle dev mode=true sdcard=true liveview=true temps nozzle 26/0 bed 24/0 nozzle 0.4 mm hardened steel errors none AMS A1 PLA PLA Matte FF6A13 33% ~330 g AMS A2 PETG PETG Basic FFFFFF 80% ~800 g protect first layer=true spaghetti=true halt=true medium $ bambu slice bracket.stl --recipe functional-petg sliced bracket-functional-petg time 35m 38s 2138 s filament 13.22 g PETG GFG00 layers 113 temps bed 70 C textured plate nozzle 252 C, first layer 252 C 3mf ./bracket-functional-petg.gcode.3mf $ bambu print send bracket-functional-petg.gcode.3mf --slot A2 --dry-run preflight + exact payload, sends nothing $ bambu print send bracket-functional-petg.gcode.3mf --slot A2 --confirm after you've checked the plate is clear $ bambu monitor --snapshot-at-layer 2 - A Bambu Lab printer in LAN Only mode with Developer Mode enabled. Since the January 2025 "Authorization Control" firmware, the printer rejects unsigned third-party control commands otherwise. - On the printer, go to Settings → LAN Only , enable LAN Only Mode , then Developer Mode . Note the access code shown there. - Developer Mode disconnects the printer from Bambu Cloud and the Handy app. That's Bambu's tradeoff, not ours. - Status bambu status is read-only and works without Developer Mode. FTPS upload and control need it. - On the printer, go to - Bambu Studio https://bambulab.com/en/download/studio installed, for slice . - ffmpeg , for camera snapshots. - Tested models: X1 Carbon. The X1/X1E/P1/A1/H2/P2S series use the same LAN protocol and should work, but they are untested. Camera snapshots are X1/H2/P2S-series only for now; P1/A1 use a different camera protocol. brew install voska/tap/bambu macOS / Linux go install github.com/voska/bambu/cmd/bambu@latest Binaries for macOS, Linux and Windows are on Releases https://github.com/voska/bambu/releases . 1. Add the printer IP + serial from the printer's Settings, or use discovery bambu printer discover listens for the printer's SSDP broadcast UDP 2021 bambu printer add workshop --host 192.168.1.50 --serial 00M00A000000000 --model X1C --nozzle 0.4 --plate textured plate 2. Store the access code in the OS keychain read from stdin; verified against the printer, read-only bambu auth set workshop prompts; or: echo CODE | bambu auth set workshop 3. Check bambu auth status --check bambu slicer info bambu status Config: ~/.config/bambu/config.toml %AppData%\bambu\config.toml on Windows, or $BAMBU CONFIG . Printers are named, and --printer / BAMBU PRINTER picks one. bambu only reads and writes config.toml , so it coexists with other tools that use ~/.config/bambu/config.json . Access code: looked up in this order: 1. The OS keychain service bambu , account = the printer serial 2. BAMBU ACCESS CODE 3. Bambu Studio's BambuStudio.conf , as a last-resort fallback It is never printed, and never written to the config. bambu recipe list prototype-pla, solid-pla, functional-pla, functional-petg bambu slice part.3mf --recipe solid-pla STL / 3MF / OBJ bambu slice part.stl --recipe prototype-pla --set wall loops=3 --filament "Bambu PLA Matte" bambu camera snapshot -o plate.jpg look at the plate bambu preflight part-solid-pla.gcode.3mf --slot 4 PASS/WARN/FAIL gates bambu print send part-solid-pla.gcode.3mf --slot 4 --confirm bambu monitor --snapshot-at-layer 2 --exec 'notify-send "$BAMBU EVENT $BAMBU STATE"' A two-filament job changes colour at a layer height, and the AMS swaps by itself: no pause, nobody at the printer. bambu slice sign.3mf --recipe prototype-pla \ --filament "Generic PLA" --color FFFFFF --filament "Bambu PLA Matte" --color 000000 \ --filament-change-z 4.0 white through Z 4.0, black from the next layer up bambu print send sign-prototype-pla.gcode.3mf --slot A4 --slot A1 --dry-run one slot per filament, in order - --filament-change-z must be a layer top. slice reads the change back from the G-code and fails exit 11 if Bambu Studio didn't place it. - The summary has grams per filament, including purge and prime-tower waste, and filament changes . - To change colour by hand at a pause e.g. a spool that isn't in the job , bambu filament load --slot A1 --confirm swaps the toolhead to another AMS slot remotely, then bambu print resume --confirm . Recipes name presets generically "0.20mm Standard" , "Bambu PLA Basic" , and bambu resolves the right system preset for your printer model and nozzle. | recipe | for | settings | |---|---|---| | prototype-pla | fit/form checks | PLA Basic, 0.20 Standard, 2 walls, 15% gyroid | | solid-pla | solid PLA parts | Generic PLA, 6 walls inner 0.45 , 100% zig-zag | | functional-pla | strong PLA parts | 6 walls @ 0.45, 100% zig-zag, 5 top/bottom, elephant-foot 0.15 | | functional-petg | strong/warm/outdoor parts | as functional-pla in PETG Basic; 252 °C, 70 °C bed, fan ≤ 30% | - No recipe adds a brim. Brims are opt-in: --set brim type=outer only --set brim width=5 . - Custom recipes: drop JSON files in ~/.config/bambu/recipes/ . The same name overrides a built-in. See bambu recipe show solid-pla . - --set key=value takes any Bambu Studio setting key. Unknown keys are rejected before slicing. At 100% infill, patterns the slicer rejects grid, gyroid, … switch to zig-zag automatically. 1. preflight checks before anything is sent: - the printer is idle, with no blocking errors informational HMS codes like "Inspecting first layer" are ignored - Developer Mode is on and an SD card is present - the 3MF is intact and sliced for this printer model, with one --slot per filament - the nozzle diameter and plate match - each slot is loaded with its filament's type a different product of that type is a WARN - each slot has enough filament unknown remaining is a WARN , and the temperatures are sane - the printer's AI protections are on WARN only and FTPS login works 2. print send re-runs preflight and refuses on any FAIL. It requires --confirm , uploads over FTPS, reads the file back to verify its MD5, then starts the job with bed leveling, flow calibration, vibration compensation and first-layer inspection on . 3. print pause|resume|stop require --confirm . resume exits 0 only once the printer reports RUNNING. It refuses mid-filament-change, and with an empty toolhead on the X1 series. 4. filament load requires --confirm and works only while paused or idle. When paused, the toolhead must hold an AMS filament and the slot must hold the same material. It exits 0 only once the printer reports that slot in the toolhead. bambu has no command that changes printer settings. bambu exit-codes | code | meaning | |---|---| | 0 | success | | 1 | error | | 2 | usage | | 3 | empty | | 4 | auth required / code refused | | 5 | not found | | 6 | forbidden Developer Mode off | | 8 | retryable unreachable/timeout | | 9 | gate failed preflight FAIL, missing --confirm , busy | | 10 | config error / slicer not found | | 11 | slice failed | | 12 | print failed | | 13 | print paused, needs a human | | 14 | monitor timeout | - bambu schema --json returns the full command tree with flags. bambu schema print send returns one command. - Every command takes --json . Errors come back as {"error":{"code","name","message","hint"}} , and the hint says what to do next. - status --watch --json and monitor --json stream NDJSON events. - There's an agent skill in skills/bambu/SKILL.md https://github.com/voska/bambu/blob/main/skills/bambu/SKILL.md . The recommended flow: status → slice → dry-run → show the human the summary, preview and snapshot → --confirm only after explicit approval. - Bambu Studio is discovered in this order: 1. BAMBU STUDIO PATH / slicer path 2. /Applications/BambuStudio.app macOS 3. bambu-studio in the usual Linux paths, Flatpak, or an extracted AppImage 4. Program Files\Bambu Studio Windows Only macOS is tested. A packed AppImage can't be read, so extract it --appimage-extract or set slicer resources . - Presets are flattened by bambu . The Bambu Studio CLI does not resolve inherits / include in preset files. Unflattened presets slice "successfully" with a generic 200×200 bed and no printer start G-code. - STEP is not supported by the Bambu Studio CLI. Export STL or 3MF instead. - OrcaSlicer isn't supported yet. Its 2.4.x CLI has the same inherits problem fixed upstream after 2.4.2 . The LAN protocol details come from these open projects' public documentation and code. No code was copied. - OpenBambuAPI https://github.com/Doridian/OpenBambuAPI GFDL docs : MQTT, FTPS and video. - ha-bambulab https://github.com/greghesp/ha-bambulab MIT : HMS decoding, stage names, print.fun Developer Mode bit, project file usage. - bambulabs api https://github.com/BambuTools/bambulabs api MIT : implicit FTPS with TLS session reuse. - Bambu Studio https://github.com/bambulab/BambuStudio AGPL-3.0 : preset resolution order and AMS mapping format were read from its source; bambu invokes the installed app and ships none of its files. Not affiliated with Bambu Lab. "Bambu Lab" is a trademark of its owner. MIT