Kiln

<!-- mcp-name: io.github.codeofaxel/kiln --> <p align="center"> <img src="docs/assets/kiln-banner-1280x640.svg" alt="Kiln" width="640"> </p>

<p align="center"> <a href="https://pypi.org/project/kiln3d/"><img src="https://img.shields.io/pypi/v/kiln3d" alt="PyPI"></a> <a href="https://pepy.tech/projects/kiln3d"><img src="https://img.shields.io/pepy/dt/kiln3d" alt="PyPI Downloads"></a> <a href="https://pypi.org/project/kiln3d/"><img src="https://img.shields.io/pypi/pyversions/kiln3d" alt="Python"></a> <a href="https://github.com/codeofaxel/Kiln/blob/main/LICENSE"><img src="https://img.shields.io/github/license/codeofaxel/Kiln" alt="License"></a> <a href="https://github.com/codeofaxel/Kiln/blob/main/policies/SIGNING.md"><img src="https://img.shields.io/badge/verified%20by-sigstore%20%2B%20SLSA-0f6fdc?logo=sigstore&logoColor=white" alt="Verified by Sigstore + SLSA"></a> <a href="https://glama.ai/mcp/servers/codeofaxel/kiln"><img src="https://glama.ai/mcp/servers/codeofaxel/kiln/badge?v=2" alt="Kiln MCP server" width="120"></a> </p>

---

The open-source MCP server for 3D printing.

Kiln lets AI agents (Claude Desktop, Claude Code, Codex, 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, over 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. No human in the middle.

pip install kiln3d

<p align="center"> <img src="docs/assets/kiln-demo-loop.svg" alt="A Kiln agent session: the user asks for a coaster with their dog's photo; Kiln designs it, checks it will print, slices, and prints it on a Bambu A1 — done in 41 minutes." width="640"> </p>

<p align="center"> <img src="docs/assets/ash-coaster.jpg" alt="A 3D-printed coaster with a relief portrait of a French bulldog and the name ASH along the bottom edge, held in a hand" width="640"> </p>

<p align="center"> <em>"a coaster with a photo of my dog Ash" — start to finish, from one sentence.</em><br> <a href="https://kiln3d.com/?utm_source=github&utm_medium=readme#demo">Watch the demo →</a> </p>

<p align="center"> _{Kiln's built in the open. If it made your printing more fun, or just saved you a headache, a ⭐ on the repo helps the next maker find it.} </p>

Quick Start

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:

<details> <summary><strong>Manual MCP config (any client, no sign-in needed)</strong></summary>

{
  "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. </details>

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

I have a Bambu A1, 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.

<details> <summary><strong>Prefer to drive it yourself? (CLI tour)</strong></summary>

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

# Add your printer (see the printer table under "Supported Printers")
kiln auth --name my-printer --host http://octopi.local --type octoprint --api-key YOUR_KEY
# Other types:
# kiln auth --name prusa  --host http://192.168.1.100      --type prusalink --api-key YOUR_KEY
# kiln auth --name klipper --host http://192.168.1.100:7125 --type moonraker
# kiln auth --name bambu  --host 192.168.1.100             --type bambu --access-code LAN_CODE --serial SERIAL

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 --save photo.jpg    # Webcam snapshot
kiln history --status completed   # Print history

# 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. </details>

<details> <summary><strong>Connect a specific agent (Claude Code, Claude Desktop, env vars)</strong></summary>

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 (16 tools) for smaller models, standard (61 tools) for mid-range, full (133 tools) for stronger models. All <!-- KILN_MCP_TOOL_COUNT:OLD --> 887 tools are available over MCP via kiln serve. </details>

<details> <summary><strong>Platform &amp; printer setup notes (Linux/WSL 2, Ethernet-only, Bambu)</strong></summary>

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 (Settings › API) | | 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 + LAN access code + serial number (all on the LCD) | | 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) | serial | 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 or OrcaSlicer 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

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

Bambu TLS &amp; 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). The X1 series (X1C, X1E) serves RTSPS, which Kiln relays via ffmpeg — so on an X1, both snapshots and the live stream need ffmpeg (brew install ffmpeg / sudo apt install ffmpeg). 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. </details>

Paid tiers (kiln3d.com/pricing) add Git-for-3D versioning, product templates, assembly manuals, fleet workflows, SSO + SCIM, ERP webhooks, and long-term audit logs.

Why Kiln?

• One control plane, any printer — 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 through the hosted proxy, or use direct mode with your own provider credentials.
• AI-native — <!-- KILN_MCP_CAPABILITY_COUNT:OLD --> 894 MCP capabilities and <!-- KILN_CLI_COUNT:OLD --> 235 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 — 25 materials, 45 brand-specific filament profiles (Bambu, Prusament, Polymaker, and more) across 11 material families. 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 or OrcaSlicer, print — all from one agent conversation.
• Safety at scale — 51 named per-printer safety profiles, 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 | 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 (via LAN MQTT) | | Prusa Link | Stable | Prusa MK4, XL, Mini+ (local REST API — type: prusalink) | | Elegoo | Stable | Centauri Carbon, Saturn, Mars series (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. |

<!-- BEGIN SUPPORTED PRINTERS (auto-generated by scripts/generate_supported_printers.py) --> Kiln ships tuned profiles for 59 models across 15 brands — Creality, Bambu Lab, QIDI, Elegoo, Prusa Research, Sovol, AON3D, Voron, AnkerMake, Artillery, FlashForge, INTAMSYS, RatRig, SparkX, Vision Miner. See the full searchable list → <!-- END SUPPORTED PRINTERS -->

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). On Pro and up, the design store itself is versioned — branches, signed releases, and cross-machine cloud sync are first-class outputs of the system, not a side database.

Git for 3D

Designs aren't text, but they need version control. Kiln treats meshes, decorations, and mechanical features as first-class versioned artifacts: branch a design, print variants, merge what works, sign releases with cryptographic proof the mesh hasn't changed.

Three things make this different from git:

1. Outcome-correlated branches. Every branch is tagged with empirical print results — success rate, warp, adhesion, cost — so cross-branch A/B is automatic, not anecdotal.
2. 3-way semantic mesh merge. Z-level / pocket / bounding-box conflict zones rendered as visual diffs, not text patches. Manufacturing tolerance, not character offsets.
3. Signed releases with mesh re-fingerprinting. Ed25519 signatures over a release manifest pinned to an exact mesh; verification re-computes the fingerprint to detect tamper after release.

Here's what visualize_branch_tree("my-coaster") actually emits — the same renderer the workshop, CLI, and your agent see (yellow = signed release, light blue = experiment, light red = branch with failed outcomes):

flowchart TD
    subgraph tree_coaster["📐 my-coaster · design"]
        v0[v0: initial]
        v1[v1: emboss-1mm<br/>83% success]
        v2[v2: emboss-2mm<br/>92% success · warp 2%]
        v3[v3: emboss-3mm<br/>warp 5%]
        v4[v4: merge winner]
        rel[🔏 1.0.0]
        v0 --> v1
        v0 --> v2
        v0 --> v3
        v2 --> v4
        v4 --> rel
    end
    classDef root fill:#f3f4f6,stroke:#374151,color:#111
    classDef released fill:#ffd60a,stroke:#111,stroke-width:3px,color:#111
    classDef experiment fill:#e0e7ff,stroke:#6366f1,color:#1e1b4b
    classDef failed fill:#fecaca,stroke:#b91c1c,color:#7f1d1d
    class v0 root
    class v1 experiment
    class v2 experiment
    class v3 failed
    class v4 experiment
    class rel released
    style tree_coaster fill:#ffffff,stroke:#e5e7eb,stroke-width:1px

| Tier | What you get | |------|-------------| | Free | Linear local design history (save / diff / rollback) | | Pro | Branch · merge · cherry-pick · Ed25519 signed releases · solo cloud sync | | Business | Team pull requests · approval gates · orgs / teams / scopes | | Enterprise | Audit log export · SSO · step-up authentication on releases · access review |

Patent pending across semantic mesh merge, outcome-correlated branching, and signed-release-with-physical-provenance.

What Agents Can Do

The Kiln MCP server (kiln serve) exposes <!-- KILN_MCP_TOOL_COUNT:OLD --> 887 tools to agents, plus prompts and resources for <!-- KILN_MCP_CAPABILITY_COUNT:OLD --> 894 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:

| Theme | Example tools | |-------|---------------| | Control | printer_status · start_print · monitor_print · pause_print · cancel_print · emergency_stop · send_gcode (validated) | | Make | generate_model (text → 3D) · slice_and_print · analyze_printability · auto_orient_model · decorate_surface (QR/photo/logo/texture) | | Find &amp; outsource | search_all_models · download_and_upload · fulfillment_quote · fulfillment_order | | Recover &amp; learn | retry_print_with_fix · resume_interrupted_print (Pro) · predict_print_failure · get_printer_insights · diagnose_print_failure_live | | Versioning (Pro+) | save_design_version · diff_design_versions · get_proven_recipe · check_design_regression | | Fleet &amp; safety | fleet_status · submit_job · preflight_check · list_safety_profiles · validate_gcode_safe |

The complete tool catalog, grouped by subsystem, lives in Project Docs.

<details> <summary>MCP resources (read-only context for agents)</summary>

| 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) | </details>

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 and OrcaSlicer 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. Normal users go through the hosted proxy (credentials stay server-side, spend limits enforced); operators can use direct mode with KILN_FULFILLMENT_PROVIDER=craftcloud + KILN_CRAFTCLOUD_API_KEY.

Decoration &amp; 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 (first 3/month free, $0.25 min / $200 max per order), shown transparently in every quote.

| Tier | Price | Headline | |------|-------|----------| | Free | $0 | Unlimited local printing, slicing, marketplace search, safety profiles, one printer, design intelligence, linear design history. | | Pro | $49/mo | Git-for-3D branching/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, fulfillment, 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. |

Full comparison at kiln3d.com/pricing. Run kiln upgrade to activate a license key. 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)
• 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.

<details> <summary><strong>Configuration reference (auth, webhooks, discovery, plugins)</strong></summary>

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. </details>

<details> <summary><strong>Modules (for contributors)</strong></summary>

| 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) 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_catalog.py | Material brand catalog, properties, and purchase-link metadata | | 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 | Bundled safety database (51 named printer models, temps/feedrates/flow) | | slicer_profiles.py | Bundled slicer profiles (auto-generates .ini files per printer) | | printer_intelligence.py | Printer knowledge base (firmware quirks, materials, failure modes) | | 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) | | gateway/ | External-provider integration gateway (as integrations launch) | | 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 <!-- KILN_CLI_COUNT:OLD --> 235 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. </details>

Documentation

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

<details> <summary>Brand assets</summary>

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. </details>

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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