Print on your Formlabs from Claude Code

Install

You need Node.js 20+ and Claude Code. Then one line:

# macOS / Linux
curl -fsSL https://mkebiclioglu.github.io/formlabs-claude-skills/install.sh | sh
# Windows (PowerShell)
irm https://mkebiclioglu.github.io/formlabs-claude-skills/install.ps1 | iex

The script adds the plugin to Claude Code and downloads PreFormServer (Formlabs' headless PreForm, about 170 MB) from Formlabs, verifying Formlabs' code signature before installing it into a folder you own. No sudo, no Python, nothing global. Read the script first if you like; it is short.

Or, inside Claude Code

/plugin marketplace add mkebiclioglu/formlabs-claude-skills
/plugin install formlabs@formlabs-claude-skills
/formlabs:setup

/formlabs:setup notices that PreFormServer is missing, asks you, and installs it through the install_preform_server tool. Same download, same signature check.

Use it

Just ask. Claude picks the right skill from plain language, or you can invoke one directly.

• "Prep ~/parts/bracket.stl for the Form 4 in Black V5 and save it as ~/jobs/bracket.form."
• "Pack these five STLs in ~/parts/batch onto the Fuse 1+ in Nylon 12 and send them to Fuse-Loud-Otter."
• "What materials can I use on the Form 4B?"
• "Find printers on my network."
• "Hollow ~/parts/bust.stl with 2 mm walls, add drain holes, and estimate print time on the Form 3."
• "Open ~/jobs/old.form, swap the part for ~/parts/v2.stl, and re-estimate."

Every flow ends with a summary: printer, material and layer height, print time, resin or powder usage, validation warnings, and the files written. Sending a job to a printer always waits for your explicit yes.

No printer yet? PreFormServer ships a built-in virtual printer for every model (list_devices shows them as VIRTUAL: Form 4, Form 4L, Fuse 1+ and so on). "Send it to the virtual Form 4" runs the whole job upload without hardware and comes back with a job id, so a workflow can be rehearsed end to end. For the network path too, preform-linux's simulated printer is a fake Form 4 on the LAN that PreFormServer discovers by IP, lists with tank and cartridge, and uploads real jobs to. The virtual and simulated SLS printers refuse jobs in the current PreFormServer, so those dry runs are SLA only.

Fuse X1: PreFormServer 3.63.0 prepares jobs for it (FUSX-1-0, Nylon 12 GF FLP12G01 at 0.11 mm, the one setting it ships) but leaves the family out of its materials list; list_printer_types adds it with an unlisted note. No other material and no auto_pack yet; models stay where import_model places them.

What's inside

Under the skills sits the formlabs-local-mcp server: 45 typed tools covering scenes, models, orientation, supports, layout and packing, hollowing, labels, drain holes, every validation check (cups, minima, supportedness, thin walls, interferences), print-time estimates, screenshots, printer discovery and printing, plus a verified PreFormServer installer. It tracks Formlabs Local API 0.9.30.

Configuration

None needed when PreFormServer is in /Applications. Everything else is an environment variable. For the plugin, put them in the env block of ~/.claude/settings.json; Claude Code passes that block to every subprocess, the MCP server included:

{
  "env": {
    "FORMLABS_ALLOWED_PATHS": "/Users/me/prints:/Volumes/Parts",
    "FORMLABS_USERNAME": "me@example.com",
    "FORMLABS_PASSWORD": "..."
  }
}

Other MCP clients

The MCP server works on its own in Claude Desktop, Cursor, VS Code, Windsurf and anything else that speaks MCP over stdio. You lose the skills but keep every tool. It only needs Node.js. Add this to the client's MCP config (claude_desktop_config.json, .cursor/mcp.json, and so on):

{
  "mcpServers": {
    "formlabs": {
      "command": "npx",
      "args": ["-y", "formlabs-local-mcp@1.0.8"]
    }
  }
}

Environment variables go in an env object next to args. For Claude Code without the plugin:

claude mcp add --scope user formlabs -- npx -y formlabs-local-mcp@1.0.8

Then ask for health_check; if PreFormServer is missing the server offers to install it. From a shell: npx -y formlabs-local-mcp@1.0.8 install-preform, and doctor instead of install-preform shows what is installed and whether Formlabs has a newer release. The package is published on npm with signed build provenance from GitHub Actions.

Linux and remote

Formlabs ships PreFormServer for macOS and Windows only. On Linux the server can talk to PreFormServer running under Wine, in a container or on the same machine, or drive one on a Mac or Windows box over ssh.

Container: preform-linux (recommended for servers and automation)

preform-linux runs the Windows build of PreFormServer under Wine and Xvfb in a container: headless, no GPU, MIT, prebuilt as ghcr.io/mkebiclioglu/preform-linux (the image holds no Formlabs software; PreFormServer is downloaded from Formlabs and signature-checked on first start). Printers are reached by IP address or through a Formlabs account, both set with environment variables:

git clone https://github.com/mkebiclioglu/preform-linux.git && cd preform-linux && mkdir jobs
PREFORM_PRINTERS=10.0.0.21,10.0.0.22 docker compose up   # FORMLABS_USERNAME/PASSWORD or a Docker secret for Fleet Control

Point the MCP server at it and tell it how the container sees your files:

PREFORM_SERVER_URL=http://127.0.0.1:44388
PREFORM_SERVER_PATH_STYLE=wine
PREFORM_PATH_MAP=/home/me/preform-linux/jobs=Z:/jobs

Files under the mapped directory are sent as Z:/jobs/...; every tool then works as on macOS. The container probes the listed printers as soon as it is up (and every ten minutes after) and logs in to your account, so list_devices shows them; print_to_printer takes a printer IP or, after login, a Fleet Control queue. LAN discovery by mDNS does not work under Wine, which is why printers are listed by address. A pipeline needs no MCP client at all: the same Local API answers on port 44388 for curl or any HTTP client, and examples/smoke.sh in that repository is a complete import, support, estimate, save run in bash.

Wine on this machine

install-preform fetches the Windows build and verifies its Authenticode signature with osslsigncode; the server starts it through wine with headless defaults and writes file paths as Z:/home/me/... automatically. Needs Wine 11.5 or newer from WineHQ (distro Wine 9.0 cannot load PreFormServer 3.63.0) and a display: PREFORM_LAUNCHER="xvfb-run -a wine" on a headless box. A weekly CI job runs the smoke test this way.

Remote mode

Run PreFormServer on any Mac or Windows machine on your network and let the MCP server on Linux drive it over ssh:

PREFORM_REMOTE_HOST=me@studio-mac.local

One ssh session, keys only, forwards a loopback port and starts PreFormServer on the remote machine so it stops when the MCP server does. Input files are copied over with scp into a per-session staging folder under the remote user's home; .form files and screenshots are copied back. The remote host needs PreFormServer installed (run install-preform there) and a POSIX shell over ssh. For a Windows remote host set PREFORM_REMOTE_SPAWN=0 and start PreFormServer yourself. Remote mode also works from a Mac to another Mac, for instance a Mac mini next to the printers.

Security

PreFormServer is a plain-HTTP server with no authentication that reads and writes files as you. The MCP server is built to keep that surface small:

• Verified installs. The installer only downloads over HTTPS from downloads.formlabs.com with Formlabs' release path layout, refuses redirects elsewhere, scans the archive for path traversal before extracting, and checks the code signature before anything is moved into place: Developer ID team KVPE3R79SR plus notarization on macOS, a valid Authenticode signature from Formlabs on Windows, osslsigncode on Linux. A failed check leaves the previous install untouched. The one-line install scripts are pinned to a release and read from this site over HTTPS.
• Path guard rails. Every file path Claude passes must be absolute, resolve (symlinks included) to somewhere under FORMLABS_ALLOWED_PATHS (your home directory by default), avoid hidden directories such as ~/.ssh, and carry the right extension: models in, .form/.png/.fps out. A prompt injection cannot turn save_form into a way to write arbitrary files.
• Credentials never enter the chat. login takes no arguments. It reads your Formlabs account from the environment and returns only your username, never tokens.
• Loopback only. Credentials are refused for any PreFormServer that is not on this machine unless you opt in.
• Short-lived and quiet. PreFormServer runs only while Claude Code is connected, and its telemetry is switched off.
• Remote mode uses ssh keys only (no password prompts), validates the host string so it can never be parsed as an ssh option, binds the forward to 127.0.0.1, and sanitizes staged file names.
• Small, pinned supply chain. The server has two runtime dependencies and a lockfile; the plugin pins an exact npm version, published from CI with signed provenance; GitHub Actions are pinned to commit SHAs and CodeQL runs on every change. Tools declare MCP annotations, so clients can ask before print_to_printer, save_form, install_preform_server or any delete.

Troubleshooting

Still stuck? Run /formlabs:setup, or open an issue on formlabs-claude-skills (plugin and skills) or formlabs-local-mcp (tools and PreFormServer).

Contribute

Both repositories are MIT and take issues and pull requests. The most useful things you can send are a transcript of a skill doing something wrong, and a note on which printer, material and OS you used, so behaviour can be fixed where it matters.

• formlabs-claude-skills: the plugin, the skills, the install scripts and this site. CONTRIBUTING.
• formlabs-local-mcp: the MCP server, its 45 tools and the PreFormServer installer. CONTRIBUTING.
• Questions, ideas and "here is what I printed" go in Discussions on either repo. Security reports go through GitHub's private reporting, see each repo's SECURITY.md.

Updating

/plugin update formlabs@formlabs-claude-skills picks up new skills and the MCP server version the plugin pins. For a new PreFormServer release, ask Claude to run install_preform_server again (or run install-preform from a shell): it is a no-op when you already have the latest.