Kiln MCP
A local MCP server and CLI: the agent writes JavaScript for a 3D model, checks it on renders and exports a GLB with source
- 305 ★ on the repository
- Last commit
- MIT
Extended access
Why this level
- The agent runs JavaScript it wrote on your machine to build models
- Setup writes instructions, skills, launchers and MCP settings into the workspace folder
Install
- Works in
Manual install
npm install @instruktlabs/kilnRun in a separate folder after npm init -y. Requires Node.js 22 or 24 LTS.
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- The agent runs JavaScript it wrote on your machine to build models
- Setup writes instructions, skills, launchers and MCP settings into the workspace folder
This is third-party code. Review the repository files before installing.
What it does
Kiln gives a coding agent a way to build procedural 3D assets. The agent writes JavaScript using Kiln's geometry and material helpers, the engine runs the program, returns rendered views and structural checks and exports a GLB. The editable source stays alongside, so an asset can be refined later by editing named parts, and every version is kept as an immutable revision. Setup creates a separate asset workspace: kiln-init puts instructions, skills, launchers and an MCP connection for the chosen agent into it, from Claude Code and Codex to Copilot and Cursor. For an existing project there is an `--adopt` mode with a preview of the changes. The package ships the kiln, kiln-init and kiln-mcp commands and a TypeScript SDK. There is a local dashboard for materials and review, a library of saved assets and a revision history. CPU rendering works without a GPU and suits geometry review, while faithful materials come from an optional local render service.
Who it is for. For game and web 3D developers who want models from an agent, checked through renders, with the source kept at hand.
Good fit when
- You need a low-poly object such as a lantern with a handle, and the agent should inspect it from several angles and fix defects
- Game assets should live as code so sizes and materials can be changed later without redrawing
- You need a GLB export or a three.js runtime profile
- You want one workspace with an asset library and revision history connected to Claude Code, Codex or Cursor
Not a fit when
- You need photorealistic models generated from a picture: Kiln builds shapes from code
- The environment has no Node.js 22 or 24: only these versions are supported
- You work in ChatGPT: it has its own remote connection setup, and public hosted Kiln is not available yet
Example request
Create a low-poly camping lantern with a carry handle. Review it from several angles, refine any problems, and save the editable source and a GLBMCP
- Transport
- stdio
- Authentication
- not required
Environment variables
KILN_RENDER- Render mode in the sample MCP connection, set to auto.
Limitations
Requires Node.js 22 or 24 LTS and npm; Bun is needed only to work on Kiln itself. CPU rendering suits geometry, and materials are checked through the optional local render service. Implicit modeling and the alternative Three.js exporter are experimental and opt-in. KTX2 texture compression needs the separate ktx2-encoder package. Hosted Kiln is invite-only: ten accounts share 200 requests a month.
How to disable. Remove the kiln_workspace server from your agent's MCP settings and delete the workspace folder. Remove the global package with npm uninstall -g @instruktlabs/kiln.
FAQ
How do I connect Kiln to Claude Code?
Install the @instruktlabs/kiln package with npm and run kiln-init with `--harness claude` for a new asset folder. It creates instructions, skills and an MCP connection named kiln_workspace.
Do I need a separate API key for models?
No. Your coding agent supplies the model, and Kiln's tools work without a separate key or an account.
How do I add Kiln to an existing project?
First run kiln-init with `--adopt` and `--check`: it shows the planned changes and writes nothing. Then repeat without `--check`. Existing instructions and unrelated settings are preserved.
What do I get at the end?
A GLB file, editable source in the .kiln.js format, a contact sheet of views as PNG and an entry in the local asset library with revision history.
Which agents does kiln-init support?
Values for the `--harness` flag: claude, codex, opencode, agy, hermes, copilot and cursor-agent. Other MCP clients connect directly.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Entries that share the main search query, and how they differ.
| Entry | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| Kiln (this entry) | no | not required | 305 | |
| Blender MCP | no | not required | 32,717 | drives an installed Blender, with no model building in code |
| img2threejs | no | 19,794 | rebuilds an object from a reference image as a procedural three.js model |
README in short
The README opens with games and interactive scenes where Kiln assets already run. Install through npm, a sample prompt for the agent and CLI and SDK instructions follow.