Kiln

---

Spawn an object into existence.

Kiln is how AI agents make real things, safely. Describe what you want to exist, and your agent designs it, checks it will print, and prints it on your own 3D printer, or has it printed and shipped to you. Every version is kept, Git-style, so you can try the risky idea and keep the one that worked.

The open-source MCP server for 3D printing.

Kiln lets AI agents (ChatGPT, Claude Desktop, Claude Code, Claude Duet, Codex, Cursor, Gemini, Grok, Hermes Agent, OpenClaw, or any custom MCP client) drive real 3D printers end to end — Bambu Lab, Creality, Prusa, Elegoo, Voron, Sovol, AnkerMake, Artillery, FlashForge, QIDI, RatRig, and SparkX. It is compatible with OctoPrint, Moonraker/Klipper, PrusaLink, and Direct USB.

In a single conversation, an agent can design a part, slice it, queue it on the right printer, monitor the camera, recover from failures, and ship the result. You approve every print, or let one printer run on its own for as long as you choose.

Reading this as an AI agent? kiln3d.com/agents is written for you rather than for the person running you: install, MCP config, the design-to-print loop, and exactly what Kiln will refuse to do and why.

pip install kiln3d

Version control for 3D printing. Branch a design to try the risky idea, compare any two versions with the numbers, merge the one that printed, and undo anything. See how it works →

Quick Start

Using Claude Desktop? Install Kiln in one click. Download kiln.mcpb and double-click it — Claude Desktop installs Kiln and wires it in (just Claude Desktop: steps 1 and 2 below are how Codex and every other AI app connect), so those steps aren't yours. Two things still are: OpenSCAD, and Kiln's terms — the command shows them and asks you to type your acceptance, which is why it's yours and not your AI's: uvx --from kiln3d kiln accept-terms. The bundle and that command both run on uv — free, with a one-line install for each platform at that link. If Claude Desktop says the server failed to start, that's uv missing: install it and restart. Updates arrive with the extension, not via kiln self-update.

Using ChatGPT, Claude, Claude Duet, Gemini, Grok, Cursor or Hermes Agent? Nothing to install. Add Kiln inside the app by its address, https://api.kiln3d.com/mcp, and sign in (Claude Duet uses the one you add in Claude; Hermes Agent takes one terminal command, on its page): it designs the part, checks it will print, and shows it in 3D, right in the chat where the app can show it. Each app's page says exactly what was seen there: ChatGPT, Claude, Claude Duet, Codex, Cursor, Gemini, Grok, Hermes Agent. To run your own printer, do the three steps below on the computer next to it.

Using OpenClaw? Tell it to install Kiln from ClawHub and it sets Kiln up on the computer it runs on: see how.

Everyone else — three steps. Then ask your AI to make something.

1. Install

pip install kiln3d

2. Connect your AI — Kiln sets itself up inside Claude Desktop, Claude Code, and Codex:

kiln signin        # create your free account
kiln install-mcp   # connects Kiln to your AI apps

Restart your AI app and it can run your printer. (Claude Code and Codex can even run this whole setup for you — the one-prompt version lives at kiln3d.com/install.) Using a different MCP client? kiln install-mcp --print prints the config — or paste it yourself:

{
  "mcpServers": {
    "kiln": {
      "command": "python3",
      "args": ["-m", "kiln", "serve"]
    }
  }
}

No install needed? Swap the command for a zero-install runner — "command": "uvx", "args": ["kiln3d", "serve"] (Python), or "command": "npx", "args": ["kiln3d"] (Node). Same server, nothing to pip install.

Drop this into Claude Desktop, Claude Code, Codex, Cursor, or any MCP-capable agent. Runs on the free tier until you sign in.

3. Ask — paste a sentence like this into your agent. Kiln does the rest:

Make me a coaster with my dog's photo on it

That's the whole happy path. Your AI does the designing, slicing, and printing — you never touch a CLI. OS-specific walkthrough (Windows, WSL 2, Linux) at kiln3d.com/install.

[!TIP] kiln doctor checks your whole setup and tells you exactly what to fix. kiln self-update upgrades in place when a new release lands.

# Discover printers on your network (mDNS + HTTP probe)
kiln discover

# Add your printer, saying which printer it is (see "Supported Printers")
kiln auth --name my-printer --host http://octopi.local --type octoprint --api-key YOUR_KEY --printer-model "Ender 3"
# Other types:
# kiln auth --name prusa  --host http://192.168.1.100      --type prusalink --api-key YOUR_KEY --printer-model MK4
# kiln auth --name klipper --host http://192.168.1.100:7125 --type moonraker --printer-model "Voron 2.4"
# kiln auth --name bambu  --host 192.168.1.100             --type bambu --access-code LAN_CODE --serial SERIAL --printer-model P1S
# A printer Kiln doesn't list yet: add who makes it, e.g. --printer-make Anycubic --printer-model "Kobra X"

kiln status                       # Printer state + job progress
kiln upload model.gcode           # Upload a file
kiln print model.gcode            # Start printing
kiln slice model.stl --print-after  # Slice an STL and print in one step
kiln print *.gcode --queue        # Batch print
kiln wait                         # Monitor a running print
kiln snapshot --output photo.jpg  # Webcam snapshot
kiln history --status completed   # Print history
kiln park --plan                  # Describe the safe park, send nothing; then --step 1, 2, 3
kiln home --plan                  # Same for the Home button; --plate-clear where Z homes onto the plate
kiln filament wipe --plan         # Same for the wipe-pad pass; --plate-clear where its plan presses the plate

# Every command supports --json for agent consumption
kiln status --json

Global option: --printer <name> targets a specific printer per command. The full command reference is in Project Docs.

Claude Code — install the plugin (one-time: install uv first if you don't have it — it's free and takes one line):

claude plugin marketplace add codeofaxel/Kiln
claude plugin install kiln@kiln

Or wire it by hand — add to .claude/settings.json (project) or ~/.claude/settings.json (global):

{
  "mcpServers": {
    "kiln": { "command": "kiln", "args": ["serve"] }
  }
}

Claude Code uses your ~/.kiln/config.yaml for printer credentials (set via kiln setup or kiln auth). No env vars needed if a printer is already configured.

Claude Desktop — add to ~/.config/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "kiln": {
      "command": "python3",
      "args": ["-m", "kiln", "serve"],
      "env": {
        "KILN_PRINTER_HOST": "http://192.168.1.100",
        "KILN_PRINTER_API_KEY": "your_key",
        "KILN_PRINTER_TYPE": "prusalink"
      }
    }
  }
}

Set KILN_PRINTER_TYPE to your backend: octoprint, moonraker, bambu, prusalink, elegoo, duet, or usb — or skip env vars entirely if you've run kiln setup.

Any other LLM (OpenRouter) — Kiln works with any model that supports OpenAI-compatible function calling, not just Claude:

export KILN_OPENROUTER_KEY=sk-or-...
kiln agent --model openai/gpt-4o
kiln agent --model meta-llama/llama-3.1-70b-instruct --tier essential

Tool tiers auto-match model capability: essential (15 tools) for smaller models, standard (60 tools) for mid-range, full (135 tools) for stronger models. All 880 tools are available over MCP via kiln serve.

Prerequisites by printer type

Printer	--type	What you need
Prusa MK4/XL/Mini+	prusalink	IP + API key (Settings › Network › PrusaLink on the LCD)
OctoPrint (any printer)	octoprint	OctoPrint URL + API key (User Settings › Application Keys)
Klipper/Moonraker	moonraker	Moonraker URL (usually http://<ip>:7125)
Creality K1/K2/Hi/Ender V4/V3 KE	creality	IP + printer_model (e.g. creality_k1_max); probes local Moonraker ports
Bambu Lab	bambu	IP + serial number + LAN access code, all on the printer's screen; LAN Only Mode and Developer Mode on to start and control prints
Elegoo (SDCP)	elegoo	IP only — no auth. Neptune 4 / OrangeStorm Giga use moonraker.
Duet / RepRapFirmware	duet	IP only, plus the machine password if one is set (M551 in config.g).
Direct USB (Marlin)	usb	USB cable only — no network. Ender 3, Prusa MK3, CR-10, any Marlin/RepRap printer.

Kiln only needs IP reachability on your LAN. Ethernet-only printers are fully supported.

Optional tools: PrusaSlicer OrcaSlicer, or BambuStudio for slicing STL → G-code (brew install --cask prusaslicer); OpenSCAD for local text-to-3D generation — install the current build (brew install --cask openscad@snapshot); set KILN_GEMINI_API_KEY to enable Gemini-generated geometry.

Linux / WSL 2

pipx installs Kiln into its own isolated environment and puts kiln on your PATH. (The pip package is kiln3d; the CLI command is kiln.)

sudo apt install pipx && pipx ensurepath
git clone https://github.com/codeofaxel/Kiln.git && cd Kiln
pipx install ./kiln
sudo apt install prusa-slicer            # optional: slicing for printing
sudo snap install openscad --edge        # optional: the design engine (current build)
kiln verify

# Update / uninstall
git pull && pipx install --force ./kiln
pipx uninstall kiln3d

WSL 2 networking: WSL 2 uses NAT, so mDNS discovery (kiln discover) won't see printers on your home network. Connect directly by IP instead (same as Ethernet-only setups).

Ethernet-only printers (no Wi-Fi)

Kiln works the same over Ethernet and Wi-Fi — it talks to printer APIs over LAN IP. Verify the printer endpoint responds, then register by IP:

curl http://<ip>/api/version                              # OctoPrint
curl http://<ip>:7125/server/info                         # Moonraker / Creality (local Moonraker)
curl -H "X-Api-Key: YOUR_KEY" http://<ip>/api/v1/status   # Prusa Link
# Bambu uses MQTT — ensure port 8883 is reachable:  nc -zv <ip> 8883

kiln auth --name my-printer --host http://<ip> --type prusalink --api-key YOUR_KEY --printer-model MK4

If PrusaSlicer isn't on your PATH: export KILN_SLICER_PATH=/path/to/prusa-slicer.

Bambu TLS & webcam

Kiln pins the printer certificate (TOFU) on first connection in ~/.kiln/bambu_tls_pins.json. Overrides:

export KILN_BAMBU_TLS_MODE=ca         # strict CA/hostname (usually fails on stock self-signed printers)
export KILN_BAMBU_TLS_MODE=insecure   # legacy, no validation — trusted LANs only
export KILN_BAMBU_TLS_FINGERPRINT=0123abcd...   # explicit SHA-256 pin

Webcam capture is model-dependent: A1, A1 Mini, P1P, P1S serve frames over TLS+JPEG (no extra software), and Kiln can show that camera as live video in the print monitor on the computer connected to the printer. The X1 series (X1C, X1E) streams RTSPS, which Kiln's live-video relay does not carry: on an X1, Kiln takes snapshots by cutting a frame from that stream with ffmpeg (brew install ffmpeg / sudo apt install ffmpeg), and there is no live video. can_snapshot is reported True for every Bambu model; on an X1 without ffmpeg, the attempt surfaces a clear model-specific error rather than failing silently.

Paid tiers (kiln3d.com/pricing) add version control on every design, product templates, assembly manuals, fleet workflows, SSO + SCIM, ERP webhooks, and long-term audit logs.

Why Kiln?

• One control plane, any printer — compatible with OctoPrint, Moonraker, Creality, Bambu Lab, Prusa Link, Elegoo, Serial. Manage a mixed fleet from one place.
• No printer? No problem — Outsource jobs to Craftcloud's 150+ manufacturing services, quoted and ordered through Kiln.
• AI-native — 887 MCP capabilities and 253 CLI commands built for AI agents. Not a web UI with an API bolted on.
• Describe it, print it — Natural-language to physical object pipeline: text or sketch → AI generation → validation → slice → print.
• Decorate anything — QR codes, photos, logos, text, SVGs, and procedural textures (tiger stripe, marble, camo, wood grain, honeycomb) embossed or debossed onto any model with one command.
• Manuals included — Multi-part prints can generate printable PDF assembly manuals with Bill of Materials, isometric step renders, mating arrows, and pause-and-check verification gates. (Business)
• Resume, don't restart — Cancelled or failed print? Resume from the exact layer it stopped on any supported FDM printer. No filament wasted. (Pro)
• Modify mid-print — Add decorations, append features, or swap materials on a live print with atomic revert if anything goes wrong. (Pro)
• Smart material routing — 38 materials and brand filament profiles for 69 brands and lines (the per-brand tune is part of Kiln Pro). Intent-based recommendations with printer capability awareness.
• Prints don't fail silently — Cross-printer learning, automatic failure recovery, closed-loop AI generation feedback (failed prints auto-improve future generations), preflight safety checks on every job.
• Doomed prints stopped early — Too big for the build plate, or a material your hotend can't melt? Caught before filament is wasted, rotated to fit when possible, one-command override. Pro shows the fix: true usable area, cleanest split, or the material to switch to.
• Search → Slice → Print — Search and download 3D models from MyMiniFactory and Cults3D (search only), auto-slice with PrusaSlicer, OrcaSlicer, or BambuStudio, print — all from one agent conversation.
• Safety at scale — a named safety profile for every supported printer, G-code validation, heater watchdog, tamper-proof audit logs. Enterprise adds encrypted G-code at rest with key rotation, lockable profiles, RBAC, SSO, fleet site grouping, per-project cost tracking, and PostgreSQL HA.

Supported Printers

Backend	Status	Printers
OctoPrint	Stable	Compatible with any OctoPrint-connected printer (Prusa, Ender, custom)
Moonraker	Stable	Klipper-based printers (Voron, Ratrig, etc.)
Creality	Stable when Moonraker is reachable	SPARKX i7, K1/K1 Max/K1C/K1 SE, K2/K2 Pro/K2 Plus/K2 SE, Creality Hi, Ender-3 V4/V3 KE, Ender-5 Max, CR-10 SE via local Moonraker. Older Marlin Creality printers use serial or octoprint.
Bambu	Stable	Bambu Lab X1C, X1E, P1S, P1P, P2S, A1, A1 Mini, A2L, H2S, H2D, H2D Pro, H2C, H3C, X2D (via LAN MQTT)
Prusa Link	Stable	Prusa MK4, XL, Mini+ (local REST API — type: prusalink)
Elegoo	Stable	Centauri Carbon (via LAN WebSocket/SDCP). Neptune 4 / OrangeStorm Giga use Moonraker.
Duet / RepRapFirmware	Beta — not yet verified against physical hardware	Duet 2 and Duet 3 controller boards, over the same HTTP interface Duet Web Control uses. Both RepRapFirmware 2 and 3 are supported. Vision Miner 22 IDEX v4 is the first catalogued machine. Type: duet.
Direct USB	Stable	Any Marlin-based printer over USB (Ender 3, Prusa MK3, CR-10, etc.). No OctoPrint or Klipper needed — just a USB cable. Type: serial.

Kiln ships tuned profiles for 76 models across 17 brands — Creality, Bambu Lab, QIDI, Prusa Research, Elegoo, Sovol, Voron, AON3D, Anycubic, Artillery, AnkerMake, FlashForge, INTAMSYS, RatRig, Snapmaker, SparkX, Vision Miner. See the full searchable list →

Architecture

graph TD
    A["🤖 AI Agent<br/><sub>Claude · GPT · Custom</sub>"]
    A -->|"CLI or MCP"| B["⚙️ Kiln<br/><sub>CLI + MCP Server</sub>"]

    B --> C["🖨️ Your Printers"]
    B --> F["🏭 Fulfillment"]
    B --> D["🛒 Marketplaces"]
    B --> V["📐 Designs (versioned)<br/><sub>Pro+</sub>"]

    C --> E1["OctoPrint"]
    C --> E2["Moonraker"]
    C --> E3["Creality"]
    C --> E4["Bambu"]
    C --> E5["Prusa Link"]
    C --> E6["Elegoo"]

    F --> F1["Craftcloud"]

    D --> I["MyMiniFactory"]
    D --> J["Cults3D"]

    V --> V1["Branches"]
    V --> V2["Signed Releases"]
    V --> V3["Cloud Sync"]

    style A fill:#1a1a2e,stroke:#e94560,color:#fff
    style B fill:#16213e,stroke:#0f3460,color:#fff
    style C fill:#0f3460,stroke:#e94560,color:#fff
    style F fill:#0f3460,stroke:#27ae60,color:#fff
    style D fill:#0f3460,stroke:#533483,color:#fff
    style V fill:#0f3460,stroke:#f59e42,color:#fff
    style E1 fill:#2d2d44,stroke:#e94560,color:#fff
    style E2 fill:#2d2d44,stroke:#e94560,color:#fff
    style E3 fill:#2d2d44,stroke:#e94560,color:#fff
    style E4 fill:#2d2d44,stroke:#e94560,color:#fff
    style E5 fill:#2d2d44,stroke:#e94560,color:#fff
    style F1 fill:#2d2d44,stroke:#27ae60,color:#fff
    style I fill:#2d2d44,stroke:#533483,color:#fff
    style J fill:#2d2d44,stroke:#533483,color:#fff
    style V1 fill:#2d2d44,stroke:#f59e42,color:#fff
    style V2 fill:#2d2d44,stroke:#f59e42,color:#fff
    style V3 fill:#2d2d44,stroke:#f59e42,color:#fff

Agents can also outsource jobs through Craftcloud fulfillment and search models on MyMiniFactory and Cults3D (search only). The design store itself is versioned — branches and cross-machine cloud sync on the designs a free Kiln account keeps, and on every design with signed releases on Pro and up — first-class outputs of the system, not a side database.

Version control for 3D printing

A printed part goes through versions the way code does, and usually ends up as bracket_final_v2_REAL.stl. Kiln keeps every version for you, so you can try the risky idea and keep the one that printed. Your agent does it in plain words: "try 4 mm walls on a branch, and keep the 3 mm one."

• Branch and undo. Try the risky idea on a branch. The working version stays untouched, and any step can be undone.
• See what changed. Compare two versions side by side or drag between them, with how much material each change added or removed.
• Prints on the record. Every print is filed under the version that made it, so you can look up how each one went.
• Merge. Bring the change that printed best back into your main design. Kiln merges what it can and asks you about the rest.
• Signed releases. Sign the version you ship, and prove later that it hasn't changed.

Plan	What you get
Free	Every version saved on your computer, with diff and rollback. With a free Kiln account: branch, merge, cherry-pick, undo and pull requests on the designs you keep, synced to the account
Pro	All of that on every design, plus the change drawn on the part, pinned comments, signed releases, versioned decorations and features, and design provenance
Business	Approval gates, team review, organizations and teams
Enterprise	Named-approver sign-off, step-up sign-in before production releases, audit log export, SSO, access reviews

See how version control works →

Tools

The Kiln MCP server (kiln serve) exposes 880 tools to agents, plus prompts and resources for 887 total MCP capabilities. Rather than list them all here, agents browse the live catalog with get_skill_manifest and ToolSearch-style discovery. A representative slice, in the order a print actually happens:

• design_session
  • Talk to Kiln about what you're making and get back a design that matches what you asked for
  • The front door for making anything: goal, geometry, preview, iterate. Free, unlimited, every tier
• compile_scad
  • Compile OpenSCAD code into a printable STL — the keyless path underneath a design session
  • No API key and no external service: the agent writes the geometry, Kiln compiles it locally
• generate_model
  • Generate a 3D model from a text prompt through an external AI provider
  • Optional, and off unless you bring your own key (Meshy, Tripo3D, Stability, Gemini)
• search_all_models
  • Search connected 3D model marketplaces in one call
  • Covers MyMiniFactory and Cults3D; downloads where the marketplace supports it
• import_step_file
  • Import a STEP (.step/.stp) CAD file and convert it for Kiln's mesh pipeline
• analyze_printability
  • Run a full printability analysis on a mesh: overhangs, thin walls, warping risk, bed fit
• auto_orient_model
  • Find the print orientation that needs the least support and prints strongest
• repair_mesh
  • Repair mesh defects — holes, degenerate faces, rounding-noise seams
  • The usual fix for a model an AI generator or a rough scan produced
• split_mesh_to_fit
  • Cut one solid too big for your build plate into printable pieces that reassemble
• recommend_material
  • Recommend materials for a use case, with the reasons and the trade-offs
• decorate_surface
  • Put any image, text, QR code, or pattern onto a model surface as an emboss or deboss
• slice_model
  • Slice a model (STL/3MF/STEP) to G-code using PrusaSlicer, OrcaSlicer, or BambuStudio
• show_on_stage
  • Turn over a file you already have — a model, or the sliced file about to print — on Kiln's interactive 3D stage, without re-making or re-slicing it
• estimate_print_cost_from_mesh
  • Estimate material cost, weight, and print time before committing the printer
• preflight_check
  • Run pre-print safety checks: printer state, temperatures, file validity, bed clearance
• start_print
  • Start a print on a connected machine
• monitor_print
  • One-shot print status: progress, temperatures, time remaining, cost, and a camera snapshot where the printer has one
• emergency_stop
  • Stop a running print immediately
• purge_filament
  • Heat the nozzle and push a short length through — the clog test, with load_filament and unload_filament beside it for a spool change
  • Reports what the printer could actually tell: where a machine reports no flow signal it says so rather than claiming success
  • Always says where the purge went: over the machine's own purge chute where Kiln knows it for your model (served through Kiln's hosted service for a printer paired to your Kiln sign-in, free, and kept on your machine so it keeps working offline), or in place with the reason — never a guessed coordinate
• wipe_nozzle
  • Clean the nozzle tip on the printer's own wipe pad (served through Kiln's hosted service for a printer paired to your Kiln sign-in, free, and kept on your machine so it keeps working offline); refuses, and says what to use instead, on any model whose pad Kiln does not know
  • Run it in steps where the pass is new to a machine: plan_only describes every motion and sends nothing; step=N sends one motion, says what it left armed, and holds the cool-down until the last step. A wipe that presses or crosses the plate asks for plate_clear on every call: a person's word, never inferred. Where a model's wipe has not yet been run on a real machine, Kiln says so and runs it in steps only
• home_axes
  • The Home button, from Kiln: your model's own homing routine where Kiln has it (served through Kiln's hosted service for a printer paired to your Kiln sign-in, free, and kept on your machine so it keeps working offline), the firmware's own routine elsewhere, a refusal that names the screen's jog controls where neither is safe
  • Run it in steps the first time: plan_only describes every motion before anything moves; step=N sends one motion and says what it left armed
• park_head
  • Move the head to the model's own spot off the plate and leave it there; never a Z touch, never heat
• plate_status
  • What Kiln knows is on the build plate: the print that left a part there and how long ago, or that it is clear — a person's word (kiln plate clear, or plate_clear on home and park) or a look through the printer's camera (look_at_plate); nothing marks it clear on its own
  • Home, park, slicing and starting a print refuse to cross a recorded part, and the refusal shows the plate through the camera where the printer has one, so an old record is checked rather than trusted
• diagnose_print_failure_live
  • Diagnose a failing print from live printer state plus the model's own geometry
• retry_print_with_fix
  • Diagnose what went wrong on the last print, then re-slice and print with the fix applied
• resume_interrupted_print (Pro)
  • Resume an interrupted print with one call on any supported FDM printer
• save_design_version
  • Save a new version of a parametric design, so you can go back to the one that worked
  • Linear history is free; branching and merges are free on the designs you keep in a free Kiln account and on every design with Pro; signed releases are Pro
• export_step
  • Export a finished design as a real STEP CAD file — analytic B-rep a machine shop can open and measure
• fleet_status (Business)
  • Live status of every printer in a fleet: state, temperatures, connection
• fulfillment_quote
  • Get a manufacturing quote from Craftcloud's network — printing without owning a printer

Beyond this slice, the catalog covers fleet orchestration, print-failure prediction, design version control, assembly manuals, and per-machine calibration; the deeper tiers are described at kiln3d.com/pricing. The complete tool catalog, grouped by subsystem, lives in Project Docs. If you are the agent, kiln3d.com/agents covers the same ground written in the second person, including the refusals worth knowing before you hit them.

Resource URI	Description
kiln://status	System-wide snapshot (printers, queue, events)
kiln://printers	Fleet listing with idle printers
kiln://printers/{name}	Detailed status for a specific printer
kiln://queue	Job queue summary and recent jobs
kiln://queue/{job_id}	Detail for a specific job
kiln://events	Recent events (last 50)

Capabilities

Search → download → print. Kiln searches MyMiniFactory and Cults3D (search only) in one call via search_all_models, downloads where supported, and uploads straight to a printer — a full design-to-print loop with no human in the middle. (Thingiverse is supported but deprecated since its Feb 2026 acquisition by MyMiniFactory; prefer MMF.) Marketplace access uses free API keys (KILN_MMF_API_KEY, KILN_CULTS3D_USERNAME + KILN_CULTS3D_API_KEY).

AI model generation. Set any provider key and it's available instantly — KILN_MESHY_API_KEY, KILN_TRIPO3D_API_KEY, KILN_STABILITY_API_KEY, KILN_GEMINI_API_KEY — or use local OpenSCAD with no key. Generated meshes are auto-validated for printability (manifold, triangle count, bounding box) before printing. kiln generate renders a 3-view preview by default.

Slicing. Wraps PrusaSlicer, OrcaSlicer, and BambuStudio for headless slicing; auto-detects installed slicers on PATH, macOS app bundles, or via KILN_SLICER_PATH. Supports STL, 3MF, STEP, OBJ, AMF with material-aware temps and smart supports.

Fulfillment (no printer required). Print through Craftcloud's network — quote, validate address, confirm, order, track — or run alongside your own printers for overflow and specialty materials. Orders go through Kiln's hosted service, which keeps provider credentials server-side and enforces your spend limits.

Decoration & textures. Emboss or deboss QR codes, photos, logos, text, and SVGs onto any model face, or apply procedural textures (tiger stripe, marble, camo, wood grain, honeycomb) with a single tool call.

Pricing

All local printing is free forever — status, file management, slicing, fleet control, and printing to your own printers cost nothing. Kiln charges a 5% orchestration fee on orders placed through external manufacturing services ($0.25 min / $200 max per order; a Pro account's first 3 orders each calendar month free; no fee on Business and Enterprise), shown transparently in every quote. Outsourced order volume is not capped on any tier.

Tier	Price	Headline
Free	$0	Unlimited local printing, slicing, marketplace search, safety profiles, one printer, design intelligence, linear design history, and branching on the designs you keep in a free account.
Pro	$49/mo	Branching on every design, signed releases, product templates, procedural textures, mid-print modification, print resume, failure recovery, nozzle-wear tracking, solo cloud sync.
Business	$199/mo	Commercial use, 3 printers + 3 seats, fleet management, cross-printer learning, QR generation, assembly manuals, team pull requests, approval gates, webhooks.
Enterprise	Contact us	Large fleets, SSO/SCIM, RBAC, audit trail, encrypted G-code at rest, white-label manuals, 99.9% SLA, on-prem/VPC.

Founding offer: half off for life while founding spots last — Pro $24.50/mo or $234/yr, Business $99.50/mo or $954/yr. Students get half off for 12 months. Details and how to claim the student price: kiln3d.com/pricing.

Full comparison at kiln3d.com/pricing. Already subscribed? Run kiln signin to put this machine on your plan. For provider-routed orders, the provider remains merchant of record; Kiln acts as orchestration infrastructure.

Safety

Kiln is safety-first infrastructure for controlling physical machines:

• Pre-flight checks validate printer state, temperatures, and files before every print
• G-code validation blocks dangerous commands (firmware reset, unsafe temperatures)
• Temperature limits enforce safe maximums (300 °C hotend, 130 °C bed)
• A person says go before every print — in your AI app's approval dialog, by typing a code Kiln shows on your screen, or at the terminal — unless you chose not to be asked: for a while (a day at most), always on a printer you named yourself (at your own terminal, or on your Kiln account page with two-factor), or by switching on auto-print yourself; stopping, pausing and watching a print never need that yes
• Confirmation required for destructive operations (cancel, raw G-code)
• Optional authentication with scope-based API keys for multi-user setups
• Structured errors ensure agents always know when something fails

Packages

This monorepo contains two packages:

Package	Description	Entry point
kiln	CLI + MCP server for multi-printer control (OctoPrint, Moonraker, Creality, Bambu, Prusa Link, Elegoo, Direct USB)	kiln or python -m kiln
octoprint-cli	Lightweight standalone CLI for OctoPrint-only setups	octoprint-cli

Development

# Create a virtualenv first (required on modern Ubuntu/Debian/WSL)
python3 -m venv .venv && source .venv/bin/activate

pip install -e "./kiln[dev]"
pip install -e "./octoprint-cli[dev]"

cd kiln && python3 -m pytest tests/ -v
cd ../octoprint-cli && python3 -m pytest tests/ -v

Run in Docker

docker compose up self-hosts the Kiln MCP server against your own printer — set KILN_PRINTER_TYPE/KILN_PRINTER_HOST/KILN_PRINTER_API_KEY first. This is a personal self-host quickstart, unrelated to the infrastructure behind the hosted api.kiln3d.com service. Prefer zero setup? kiln3d.com runs the hosted version for you.

Authentication (optional)

Optional API-key auth for MCP tools, disabled by default. Scopes: read, write, admin. Read-only tools never require auth.

export KILN_AUTH_ENABLED=1
export KILN_AUTH_KEY=your_secret_key
export KILN_MCP_AUTH_TOKEN=your_secret_key   # clients provide their key here

Webhooks

Register HTTP endpoints for real-time event notifications:

register_webhook(url="https://example.com/hook", events=["job.completed", "print.failed"])

Payloads are signed with HMAC-SHA256 when a secret is provided. Redirects are blocked by default (KILN_WEBHOOK_ALLOW_REDIRECTS=0); when enabled, each hop is SSRF-validated and HTTPS→HTTP downgrade is blocked.

Printer discovery

kiln discover   # mDNS/Bonjour + HTTP subnet probing

Finds OctoPrint, Moonraker/Creality, Bambu, Elegoo, and Prusa Link printers. If discovery returns nothing, register directly by IP with kiln auth.

Third-party plugins

Entry-point plugins are default-deny in production (KILN_PLUGIN_POLICY=strict). Allow specific plugins with KILN_ALLOWED_PLUGINS=my_plugin,other_plugin, or set KILN_PLUGIN_POLICY=permissive for temporary migration compatibility.

Module	Description
server.py	MCP server with tools, resources, and subsystem wiring
printers/	Printer adapter abstraction (OctoPrint, Moonraker, Creality, Bambu, Prusa Link, Elegoo)
marketplaces/	Model marketplace adapters (MyMiniFactory, Cults3D, Thingiverse, metadata-only sources)
slicer.py	Slicer integration (PrusaSlicer, OrcaSlicer, BambuStudio) with auto-detection
registry.py	Fleet registry for multi-printer management
queue.py	Priority job queue with status tracking
scheduler.py	Background job dispatcher with history-based smart routing
events.py	Pub/sub event bus with history
persistence.py	SQLite storage for jobs, events, and settings
webhooks.py	Event-driven webhook delivery with HMAC signing
auth.py	Optional API key authentication with scope-based access
discovery.py	Network printer discovery (mDNS + HTTP probe)
generation/	Text-to-model generation providers (Meshy, Tripo3D, Stability AI, Gemini Deep Think, OpenSCAD) with auto-discovery, mesh validation, and printability analysis
consumer.py	Consumer workflow for non-printer users (address validation, material recommendations, timeline/price estimation, onboarding)
cost_estimator.py	Print cost estimation from G-code analysis
materials.py	Multi-material and spool tracking
material_inventory.py	Fleet material inventory and assignment tracking
bed_leveling.py	Automated bed leveling trigger system
streaming.py	MJPEG webcam streaming proxy
cloud_sync.py	Cloud sync for printer configs and job history
plugin_loader.py	Internal tool-plugin discovery and registration
plugins/	Focused MCP tool modules loaded by the plugin loader
gcode.py	G-code safety validator with per-printer limits
gcode_interceptor.py	Rule-based G-code interception and safety rewriting
safety_profiles.py	Per-printer safety limits (temps, feedrates, flow) for every supported model, served per printer from Kiln's catalogue, over a bundled generic floor for any other machine
slicer_profiles.py	Bundled slicer profiles (auto-generates .ini files per printer)
printer_intelligence.py	Printer roster and spec sheets: each machine's limits, per-material temperatures and motion facts, with the spec sheet served per printer from Kiln's catalogue (curated quirks, calibration recipes and failure modes are in Kiln Pro)
pipelines.py	Pre-validated print pipelines (quick_print, calibrate, benchmark)
assembly.py	Multi-part assembly validation and manual planning support
design_versions.py	Local design history, version records, diffs, and rollback primitives
mesh_validation_pipeline.py	Multi-gate printability validation pipeline
model_visualizer.py	Local model preview rendering
tool_schema.py	OpenAI function-calling schema converter (MCP → OpenAI format)
tool_tiers.py	Tool tier definitions (essential/standard/full) for model capability matching
agent_loop.py	Generic agent loop for any OpenAI-compatible API (OpenRouter, direct, etc.)
openrouter.py	OpenRouter integration with model catalog and auto-tier detection
data/	Bundled JSON databases (safety profiles, slicer profiles, printer intelligence)
heater_watchdog.py	Auto-cooldown watchdog for idle heaters
wallets.py	Crypto wallet configuration (Solana/Ethereum for donations and fees)
pro_tool_manifest.json	Public manifest for kiln-pro tool discovery and REST proxy stubs
decoration_quota.py	Free-tier decoration quota tracking and tier resolution hooks
cli/	Click CLI with 253 commands and JSON output

kiln-pro (kiln3d.com) extends public Kiln with paid-tier REST serving, billing, licensing, SSO, RBAC, G-code encryption, uptime reporting, team administration, and project-cost workflows. Public Kiln exposes only the interface/proxy surface for those capabilities; the private implementation stays in kiln-pro.

Documentation

Document	Description
Project Docs	Complete reference (CLI, MCP tools, adapters, config)

Logo files live in docs/assets/ — all vector SVG, scale to any size.

File	Use
kiln-banner-1280x640.svg / kiln-banner-1280x640-light.svg	GitHub / social media banner (dark / light scheme)
kiln-logo-dark.svg / kiln-logo-light.svg	Primary mark + wordmark (dark / light bg)
kiln-horizontal-dark.svg / kiln-horizontal-light.svg	Horizontal lockup (dark / light bg)
kiln-logo-dark-notext.svg	Mark only (dark bg)
kiln-favicon-256.svg	Favicon / app icon
kiln-logo-transparent.svg / kiln-logo-transparent-dark.svg	Transparent bg (for dark / light UIs)
kiln-mark-1024.svg	Square mark tile — profile picture, app tile (1024×1024)
kiln-x-header-1500x500.svg	Social header (1500×500)
wallpapers/kiln-wallpaper-iphone-*.svg	iPhone wallpapers
wallpapers/kiln-wallpaper-macbook-*.svg	MacBook wallpapers

Every file above is generated from one geometry, so the mark is identical across all of them. Please don't redraw it — scale the vector instead.

Support Development

Kiln is free, open-source software. If you find it useful, consider sending a tip:

• Solana: kiln3d.sol
• Ethereum: kiln3d.eth

Positioning

Messaging clarification (February 24, 2026): We clarified wording to remove ambiguity and align with existing intent; no strategy change. Kiln is orchestration and agent infrastructure for fabrication workflows. Kiln does not operate a first-party decentralized manufacturing marketplace/network. Kiln integrates with third-party providers and external provider/network adapters as integrations are available.

Non-goals: operating a first-party decentralized manufacturing marketplace/network; replacing partner supply-side networks; owning provider marketplaces instead of integrating with them; acting as merchant of record for provider-routed manufacturing orders.

License

Kiln is a project of Hadron Labs Inc.

AGPL-3.0 License — open source with copyleft. Commercial licensing available for companies that need proprietary use.

By contributing, you agree to the Contributor License Agreement.

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Also listed on Smithery and LobeHub:

Trademarks

OctoPrint is a registered trademark. Other product and company names are trademarks of their respective owners; Kiln is not affiliated with or endorsed by them.