prusactl

prusactl

Hand your Prusa 3D printer to an AI agent.
An MCP server that talks to the printer directly on your network, and through Prusa Connect from anywhere — and a CLI that does everything the agent can.

[CI] [Go version] [MCP server] [License: MIT]

prusactl mcp gives an agent such as Claude hands on your printer. It can:

• Watch: check state, temperatures, job progress, and the camera (over RTSP with setup --camera, or through Connect).
• Print: upload files, start them, pause, resume, and stop, and (with Connect) queue them.
• Control: heat, home, move, load and unload filament, and level the bed: through Connect at any time, or as G-code while the printer is idle.
• Answer the printer: press the buttons on dialogs shown on its screen, such as runout or errors. Needs Connect.
• Run G-code: any G-code, over the direct connection, while the printer is idle.

It is one Go binary; no browser is needed. Setup is two terminal prompts.

Things you can ask

How's the print going? Show me the camera.

Print ~/Downloads/bracket.bgcode.

Preheat for PETG.

Object 3 is spaghetti. Cancel just that one.

The printer is showing a dialog. What does it say?

What did I print this week, and how many failed?

Cancelling one object, reading a dialog, and print history go through Prusa Connect, so those need prusactl login; the rest works directly. So does the camera, once you tell prusactl where it is (see The camera).

Install

Homebrew (macOS and Linux):

brew install trevin-lee/tap/prusactl

This builds prusactl from source, so Homebrew installs Go first if you don't have it; the build itself takes seconds. Tab completion for bash, zsh, and fish comes with it. Update with brew upgrade prusactl. To remove it, see Uninstall.

Installed prusactl 0.1.3 or earlier? That was a cask. Switch once with brew uninstall --cask prusactl && brew update && brew install trevin-lee/tap/prusactl. Your saved printer and Prusa Connect session are kept.

A downloaded binary: get the archive for your system from Releases: macOS (universal), Linux (x86-64, ARM64, ARMv7 such as a Raspberry Pi), or Windows (x86-64, ARM64). checksums.txt lists their SHA-256 sums.

tar -xzf prusactl_*_linux_arm64.tar.gz   # macOS and Linux: unpack the one you downloadedsudo install prusactl /usr/local/bin/    # or any other folder on your PATH

On Windows, unzip it and put prusactl.exe in a folder on your PATH. The binaries aren't code-signed: if macOS won't open it because it can't verify the developer, run xattr -d com.apple.quarantine /usr/local/bin/prusactl. To update, replace the file with a newer release. prusactl help completion shows how to add Tab completion.

Go:

go install github.com/trevin-lee/prusactl/cmd/prusactl@latest

This puts it in $(go env GOPATH)/bin, which needs to be on your PATH. It needs Go 1.26.6 or newer; recent Go versions fetch that on their own.

Check it worked with prusactl --version.

Uninstall

First remove what prusactl saved: prusactl setup --forget deletes the printer's address and password, and prusactl logout deletes the Prusa Connect session. Then remove the program with brew uninstall prusactl, or by deleting the file. All that's left is a prusactl folder holding an empty lock file, in your config directory (~/Library/Application Support on macOS, ~/.config on Linux, %AppData% on Windows); delete it too if you like.

Quick start

prusactl setup 192.168.1.50    # the printer's address; asks for its PrusaLink passwordprusactl status
prusactl setup --camera rtsp://192.168.1.60/live   # optional: the camera, no Connect neededprusactl login                 # optional: Prusa Connect, for remote access, camera, dialogs

The PrusaLink password is on the printer under Settings → Network → PrusaLink. PrusaLink is on by default; if someone turned it off, turn it back on there.

setup saves one printer for the direct route; running it again for another printer replaces the first (it says so). With several printers, set up the one you use most and reach the others through Prusa Connect.

Connect an AI agent

Claude Code:

claude mcp add --scope user prusa -- "$(command -v prusactl)" mcp

$(command -v prusactl) saves the full path, so it works even when the app isn't started from a terminal that has your PATH.

Any other MCP client: add prusactl as a stdio server, using the path that command -v prusactl prints (where prusactl on Windows):

{  "mcpServers": {    "prusa": { "command": "/opt/homebrew/bin/prusactl", "args": ["mcp"] }  }}

The MCP bundle: each release includes prusactl.mcpb, which carries its own copy of prusactl for macOS, Linux x86-64, and Windows x86-64. Open it in an app that installs MCPB extensions, such as Claude Desktop (double-click the file), and enter the printer's address and PrusaLink password when asked. The bundle covers the direct route; Prusa Connect sign-in still needs prusactl login from an installed copy.

prusactl is also listed in the MCP Registry as io.github.trevin-lee/prusactl, for clients that browse it.

A skill for Claude Code: skills/prusactl/SKILL.md teaches an agent the workflows (checking status, starting a print after looking at the plate, watching for failures, updating firmware) and the hazards. Copy the folder to ~/.claude/skills/prusactl/ (or a project's .claude/skills/) to use it.

How it works

flowchart LR    agent["AI agent<br/>(Claude Code, …)"] -- "MCP over stdio" --> px["prusactl"]    you["You, in a terminal"] --> px    px -- "local network<br/>PrusaLink API" --> printer["Your printer"]    px -. "internet, optional" .-> connect["Prusa Connect"]    connect <-.-> printer    px --- keychain[("OS keychain")]

prusactl reaches the printer two ways, and each tool picks one:

The direct route is used whenever the printer answers. Otherwise, or for Connect-only features, the tool goes through Connect. Results from tools that can take either route say which one they used (via); the rest always use the route their feature needs.

The camera

The Buddy3D camera is not part of the printer. It is a separate Wi-Fi device that talks to Prusa Connect on its own and serves a video stream at rtsp://<camera-ip>/live; the printer's PrusaLink has no camera endpoint (Buddy firmware serves none), so a direct connection alone can't show it. Tell prusactl where the camera is and it grabs one frame at a time with ffmpeg, which must be on your PATH:

prusactl setup --camera rtsp://192.168.1.60/live   # find the camera's IP in your routerprusactl camera snapshot.jpg

A snapshot comes from the first source that works: the printer's own /api/v1/cameras/snap, if its PrusaLink has one (other PrusaLink builds do); the saved RTSP address; then Prusa Connect. via: "direct" limits it to the first two, via: "connect" to Connect. PRUSACTL_CAMERA_URL overrides the saved address. An address with a user or password is refused: ffmpeg would get the password on its command line, where any local user can read it with ps, and it would sit in plain text in the config. The Buddy3D camera takes none.

Only plain rtsp:// addresses are accepted. rtsps:// is refused on purpose: FFmpeg 7.1.5 completes the TLS handshake with a self-signed certificate and sends the camera's credentials even with -tls_verify 1 and -ca_file, because its RTSP code never hands those options to the TLS layer. The Buddy3D camera serves plain RTSP, so this costs nothing there. Residual risk: plain RTSP sends the video unencrypted, so anyone on your network can watch it; keep the camera off untrusted networks.

Signing in to Prusa Connect

prusactl login asks for your Prusa Account email and password, plus a 2FA code if your account has one. It fills in Prusa's own login page over HTTPS the same way a browser would. It then trades the resulting code for tokens, using the OAuth + PKCE flow of the Connect web app.

Letting an AI agent sign in for you. prusactl login --manual never sees a password. It prints a Prusa Account link on a line of its own (and opens it in your browser unless you pass --no-open), then reads one line from stdin: the address the browser ends on after you approve, which looks like https://connect.prusa3d.com/login/auth-callback?code=...&state=... (the bare code= value also works). An agent can drive it; skills/prusactl/SKILL.md says how. There is no loopback mode: Prusa Account rejects a 127.0.0.1 redirect for the Connect client ("Mismatching redirect URI"), so the code can only be read from the address bar. It also relies on Connect's auth-callback page leaving a code alone when its state isn't one the page issued, which is how the page behaves today. If Prusa changes that, the sign-in fails at the token step, and the fix is an update to prusactl.

• Your password is sent only to account.prusa3d.com and is never stored.
• Where tokens are kept: the OS keychain (macOS Keychain, Secret Service, or Windows Credential Manager), under the service prusactl. A machine without one, such as a headless Raspberry Pi, gets secrets.json in prusactl's config directory instead, readable only by you; PRUSACTL_KEYRING=file forces that.
• Staying signed in: tokens refresh on their own. Prusa rotates refresh tokens, so refreshes are coordinated between processes. Several agents can share one session without signing each other out.
• Google or Apple sign-in accounts need a Prusa Account password set before this works.

The printer's PrusaLink password is kept in the same keychain.

MCP tools

Every printer argument accepts a name, serial number, or Connect UUID. With one printer you can leave it out. via: "direct" or via: "connect" forces a route.

CLI

prusactl setup [ADDRESS]           connect directly to the printer on your networkprusactl login [--manual]          optional: sign in to Prusa Connectprusactl logout                    forget the Prusa Connect sessionprusactl status                    printer state and how it is reachableprusactl mcp                       run the MCP server on stdio
prusactl printers                  the printers prusactl can reachprusactl print FILE                upload a sliced file and start printing itprusactl start PATH                start a file already on the printerprusactl pause | resume | stop     control the running printprusactl gcode "G28" ["M104 S215"] run G-code as a one-off jobprusactl dialog BUTTON             answer a question on the printer's screenprusactl files ls|get|put|rm       browse and manage files on the printerprusactl cloud ls|rm               files in Prusa Connect's cloud storageprusactl queue ls|add|rm           the Prusa Connect print queueprusactl jobs [JOB-ID]             print history, or one jobprusactl events                    the printer's recent eventsprusactl telemetry                 recorded temperatures and speedsprusactl transfers                 file transfers in progressprusactl camera [FILE]             save a snapshot from the printer's camera (RTSP or Connect)prusactl cmd ls|send|status        run a firmware command through Prusa Connectprusactl firmware [update]         the printer's firmware; update installs the latest via Connect
prusactl api [METHOD] PATH [JSON]  /api/... to the printer, /app/... to Prusa Connectprusactl completion bash|zsh|fish  print a shell completion scriptprusactl help [COMMAND]            the command list, or one command's detailsprusactl version                   print the version (--version does the same)

The printer commands run the very tools the MCP server exposes, over an in-memory connection, so the CLI and an agent reach the printer by the same code path with the same safety checks, and neither can do something the other can't. Most of them take --printer NAME to pick a printer and --via direct or --via connect to force a route; prusactl help <command> lists what each one accepts. Every one takes --json.

The same plate check applies: after a finished or stopped print, anything that starts a job asks whether the plate is clear. --plate-clear answers yes, for scripts.

prusactl help <command> (or <command> --help) explains a command and its flags, and flags work before or after the arguments. Tab completion covers commands, flags, and their values: Homebrew installs it for bash, zsh, and fish, and prusactl help completion shows how to add it otherwise.

prusactl setup --forget removes the saved printer and camera. --api-key uses a PrusaLink API key instead of the password, --password-stdin reads the secret from a pipe, and --camera URL saves the camera's RTSP address (on its own it leaves the printer alone; --no-camera forgets just the camera).

prusactl api masks API keys and tokens in responses (Connect's printer record carries the PrusaLink and Connect keys), so its output is safe to paste or hand to an agent. --raw shows them.

Firmware

prusactl firmware shows the firmware the printer runs and the latest one Prusa Connect offers for it. prusactl firmware update has Connect copy its hosted .bbf to the printer's USB drive and then installs it with the FLASH command, which restarts the printer. It waits for the copy. Without --version it goes by Connect's own verdict on the firmware, and refuses to decide when there is none.

prusactl firmware                       # running vs latestprusactl firmware update [--version X]  # copy, then install

FLASH is accepted only while the printer is idle, ready, finished or stopped. While a print is running it refuses before copying anything; run it again when the print has ended. Whether an update is due is Prusa Connect's own verdict, so a printer newer than Connect's latest is never downgraded unless you pass --version. The printer may ask for a confirmation on its screen. Firmware goes through Prusa Connect only, so you need prusactl login.

Limits

• It has no hands. It can't clear the build plate, swap a spool, or fix a clog. The tool descriptions tell the agent to check the printer (and the camera, if any) before starting a print or moving anything. Tools that start a job refuse a busy printer. After a finished or stopped print, everything that starts a job or moves toward the plate (start_print, upload_file with print, run_gcode, and send_command HOME, MOVE, MOVE_Z, MESH_BED_LEVELING, or START_PRINT) also needs plate_clear: true, since the last part may still be there. Marking the printer ready is the same confirmation. api_request is raw access and skips these checks.
• plate_clear is the agent's own claim. Nothing can check that the plate is empty, so the tool descriptions tell the agent to verify it with a camera snapshot or the user's word before passing it. Deletes are permanent, and pausing is the recommended first move for a print that looks wrong.
• run_gcode runs as a tiny print job. So it only works while the printer is idle, and it shows up in the printer's history. It also leaves the file /usb/prusactl-macro.gcode on the printer, which each run overwrites.
• Connect's API is unofficial. Prusa doesn't publish it; prusactl uses the same endpoints as connect.prusa3d.com, so a change on Prusa's side can break the Connect route. The direct route uses Prusa's documented PrusaLink API. If either changes, prusactl says so instead of misbehaving: "Prusa Connect answered in a way this version of prusactl doesn't recognize: …", naming the request and what was unexpected. Updating prusactl usually fixes it; if the newest version doesn't, report the message as an issue.

Configuration

Development

go test ./...go vet ./...

Releases are cut by pushing a vX.Y.Z tag. CI builds the binaries, updates the Homebrew tap, attaches the MCP bundle, and publishes to the MCP Registry. See CHANGELOG.md.

License

MIT.

prusactl is an independent project. It is not affiliated with or endorsed by Prusa Research. Prusa and Prusa Connect are trademarks of Prusa Research a.s.