formlabs-local-mcp

A Model Context Protocol server that exposes the Formlabs Local API to any MCP-compatible AI tool — Claude Code, Claude Desktop, Cursor, VS Code, and others.

Drive your Formlabs printers from a chat prompt:

"Import ~/parts/bracket.stl, auto-orient it, generate supports, estimate the print time, then send it to my Form 4."

The MCP server wraps PreFormServer's HTTP API as a set of typed tools the model can call directly.

Status

Early alpha. The tool surface is complete for the common SLA/SLS preparation workflow, but has only been tested against the API spec — not yet validated against real hardware. PRs and bug reports welcome.

Requirements

• Python ≥ 3.10
• The PreFormServer executable, downloaded from the Formlabs API downloads page. PreFormServer is a headless build of PreForm; it must be running for the MCP server to do anything.

Install

Clone the repo and install it into a virtual environment:

git clone https://github.com/mkebiclioglu/formlabs-local-mcp.git
cd formlabs-local-mcp
python -m venv .venv
source .venv/bin/activate
pip install -e .

The pip install -e . step creates a formlabs-local-mcp script inside .venv/bin/ — note its absolute path (e.g. /Users/you/formlabs-local-mcp/.venv/bin/formlabs-local-mcp). You'll point your MCP client at it.

Configure your MCP client

Claude Code

Easiest path is the CLI:

claude mcp add formlabs \
  -s user \
  -e PREFORM_SERVER_PATH=/path/to/PreFormServer.app/Contents/MacOS/PreFormServer \
  -- /absolute/path/to/formlabs-local-mcp/.venv/bin/formlabs-local-mcp

Or edit ~/.claude.json (or .claude/mcp.json for project scope) directly:

{
  "mcpServers": {
    "formlabs": {
      "command": "/absolute/path/to/formlabs-local-mcp/.venv/bin/formlabs-local-mcp",
      "env": {
        "PREFORM_SERVER_PATH": "/path/to/PreFormServer.app/Contents/MacOS/PreFormServer"
      }
    }
  }
}

Confirm it's wired up: claude mcp list should show formlabs: ✓ Connected.

Claude Desktop

Add the same mcpServers block to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows). Restart Claude Desktop after editing.

PreFormServer lifecycle

The MCP server has two modes for talking to PreFormServer:

1. Spawn mode (recommended). Set PREFORM_SERVER_PATH to the absolute path of the PreFormServer executable. The MCP server starts it on launch, waits for READY FOR INPUT on stdout, and shuts it down on exit.
2. External mode. If PREFORM_SERVER_PATH is unset, the MCP server assumes PreFormServer is already running on localhost:44388 (or whatever PREFORM_SERVER_PORT / PREFORM_SERVER_URL you set).

Environment variables

Variable	Default	Purpose
PREFORM_SERVER_PATH	(unset)	Absolute path to the PreFormServer executable. If set, the MCP server spawns and supervises it.
PREFORM_SERVER_PORT	44388	Port the PreFormServer listens on.
PREFORM_SERVER_URL	http://localhost:$PORT	Override the base URL entirely (e.g. for a PreFormServer on another machine).
PREFORM_SPAWN	1	Set to 0 to disable spawning even if PREFORM_SERVER_PATH is set.
PREFORM_POLL_INTERVAL	2.0	Seconds between operation status polls.
PREFORM_POLL_TIMEOUT	600	Maximum seconds to wait for any async operation.

Tools

The MCP server exposes ~25 tools across these categories:

Category	Tools
Health	health_check
Scene	create_scene, list_scenes, get_scene, delete_scene, load_form
Models	import_model, update_model, delete_model
Auto-prep	auto_orient, auto_support, auto_layout (SLA), auto_pack (SLS)
Modify	hollow_model, add_drain_holes
Validate	estimate_print_time, get_print_validation
Export	save_form, save_screenshot
Devices	list_devices, discover_devices
Print	print_to_printer
Materials	list_materials
Auth	login, logout

File path parameters must always be absolute — PreFormServer rejects relative paths, environment variables, and URLs.

Companion skills

For Claude Code, the formlabs-claude-skills repo ships opinionated workflow skills (e.g. /formlabs-print) that orchestrate these tools end to end.

Development

In your already-cloned repo:

source .venv/bin/activate
pip install -e ".[dev]"
pytest

To run the server directly against a local PreFormServer (outside of an MCP client, useful for debugging):

PREFORM_SERVER_PATH=/path/to/PreFormServer formlabs-local-mcp

License

MIT. The Formlabs API itself is governed by the Formlabs API License Agreement; this MCP server only makes HTTP calls to it and does not redistribute any Formlabs code.

Disclaimer

This is an independent integration. It is not affiliated with, endorsed by, or supported by Formlabs Inc.