Kiln

What codeofaxel/Kiln MCP server does

The codeofaxel/Kiln MCP server is an open-source MCP application for controlling physical 3D printers. It is designed to cover a print workflow from preparing a model through monitoring a running job. The README names Bambu Lab, Creality, Prusa, Elegoo, Voron, Sovol, AnkerMake, Artillery, FlashForge, QIDI, RatRig, and SparkX printers, using OctoPrint, Moonraker/Klipper, PrusaLink, or direct USB connections.

The supplied MCP tool list contains load_filament and unload_filament. The project documentation also describes a wider server interface and a command-line interface for discovering printers, checking status, uploading G-code, starting prints, slicing STL files, queueing jobs, waiting for completion, taking webcam snapshots, and viewing print history. Those broader operations are documented as Kiln capabilities, but the exact MCP tool names for them are not provided here.

How it works

Kiln runs locally and connects to a printer backend configured by the operator. Printer types include octoprint, moonraker, bambu, prusalink, elegoo, duet, and usb. A configured printer can be selected by name for CLI commands, while the MCP server exposes printer operations to a compatible AI client.

The README gives a design-to-print workflow in which an agent can prepare an object, slice it, send it to a printer, and monitor progress. Camera snapshots and print history support observation, while queueing and status commands support multi-step jobs. The project also documents model-dependent tool tiers for its agent mode and says that MCP clients can access its full tool set.

Setup and configuration

Install the Python package with pip install kiln3d. The documented zero-install server command is uvx kiln3d serve. A manual MCP configuration can also launch python3 -m kiln serve. Claude Desktop users can install the published kiln.mcpb bundle, while other setup paths include kiln signin followed by kiln install-mcp.

Printer credentials can be stored through Kiln setup or authentication commands. Environment-based configuration uses KILN_PRINTER_HOST, KILN_PRINTER_API_KEY, and KILN_PRINTER_TYPE; these are shown as an alternative to saved configuration, not as universally required variables. Backend-specific credentials vary: OctoPrint and PrusaLink use API keys, Bambu uses a LAN access code and serial number, and Moonraker is configured with its URL.

The codeofaxel/Kiln MCP server can be connected to Claude Desktop, Claude Code, Codex, Cursor, or another MCP-capable client. The README states that manual MCP configuration does not require sign-in and can run on the free tier. OpenSCAD is also identified as a prerequisite for the documented Claude Desktop bundle workflow.

Tools and capabilities

• Load filament with load_filament.
• Unload filament with unload_filament.
• Discover printers on a local network through the CLI.
• Upload G-code and start or queue print jobs.
• Slice an STL and optionally print it afterward.
• Monitor job status, wait for completion, capture webcam snapshots, and inspect print history.

Limitations and notes

The server controls real hardware, so printer connectivity and correct backend credentials are required for useful printer operations. Support depends on the printer connection method and the selected backend. The README describes many capabilities beyond the two tools listed in the supplied listing; verify the installed release if a workflow depends on a specific MCP tool.

The project is licensed under AGPL-3.0. Its setup also includes terms acceptance through kiln accept-terms, and its documentation distinguishes between signed-in account setup and manual local MCP configuration.