Kiln

Build and revise 3D assets with your coding agent.

The agent writes JavaScript using Kiln's geometry and material helpers. Kiln runs the program and returns rendered views and structural checks so the agent can review its work. Export the asset as a GLB and keep the source for later changes.

Kiln runs locally. It includes an MCP server, a CLI, a TypeScript library, and skills for authoring, editing, animation review, and scene composition. Your agent supplies the model; Kiln does not require a separate model API key for its tools.

Walk the Farm, drive across Golden Gate, or explore the Foundry Floor, or fight as Achilles or Hector in Troy. The scenes put Kiln assets to work with animation, levels of detail and interactive controls.

Farm	Golden Gate
Crops, animals and working farm buildings.	Bridge, terrain, water and drivable traffic.

Foundry Floor: the campus	Inside the fab

Foundry Floor pairs a factory campus with a representative floor in its southwest building. AMRs, robot arms and overhead transport move containers through the fab.

Six reusable vehicles, shown with the gallery's live body-paint controls:

Hatchback · yellow	Sedan · blue	SUV · green
Pickup · red	Box truck · silver	Transit bus · blue

Browse the current assets · Farm pack · Vehicles pack · Scenes

All five packs offer Runtime assets for applications and Editable assets with authoring sources, materials and the available revisions. The vehicle viewer includes live paint colours. Pack source and the maintained Farm, Bridge, Foundry and Troy scene code are in this repository. Large generated models and archives are downloaded explicitly from Cloudflare. The Blender and Unity guide describes the tested import workflows and their limits.

Kiln's local dashboard adds optional projects, a material library and Live Review. Standalone assets remain a complete workflow; projects add shared briefs, inventories, art direction and material pins when useful.

Earlier examples remain in the gallery and example provenance. They are historical showcases, not golden outputs or a model ranking. Screenshots above show the v0.9 review builds; image provenance.

Version 0.10.0 is the v1 readiness release: the stdio server serves protocol revision 2026-07-28 beside the 2025 handshakes and answers before the engine loads, the three record tools are flat objects with an action field, every tool result is bounded and leads with its verdict, and the generated workspace guide and skills are shorter. It builds on 0.9.0's optional projects, material library, Live Review and calibrated review-neutral-v1 lighting rig. CHANGELOG.md lists the changes with each breaking one marked, and the migration notes list what an existing author will notice.

0.10.0 is the source and site release for dogfooding. Its package tarball is attached to the v0.10.0 release with SHA256SUMS.txt and the installed-package receipts, as later releases' tarballs are on the releases page; registry publication is deferred to v1.0 after feedback, and the site deployment publishes no package.

Install and start an asset workspace

Use Node.js 20.15.0+ on the 20.x line, or 22.2.0 and later, with npm. Download the tarball and SHA256SUMS.txt from the release and check the tarball against the checksum file before installing. Use only a tarball actually attached to a release, with that release's documentation; a checkout ahead of the release builds its own package. Bun and a separate model API key are not required to install the tarball:

mkdir kiln-install
cd kiln-install
npm init -y
npm install /absolute/path/to/kiln-engine-VERSION.tgz --omit=dev --include=optional
npm exec --offline -- kiln-init ../my-assets --harness opencode  # or claude, codex, hermes, agy, copilot, cursor-agent
cd ../my-assets
# Follow START.md for your harness

The installation stays separate from your asset workspace. Choose claude, codex, opencode, hermes, agy, copilot, or cursor-agent for --harness. The installation guide covers checksums, local package builds, existing-workspace upgrades and platform qualification. For a new installation, a maintained Node 22 or 24 LTS release is recommended; Node 20 compatibility accommodates existing distribution-managed installations.

Run from a checkout

For engine development, install Bun 1.4.2, then:

git clone --filter=blob:none https://github.com/matthew-kissinger/kiln
cd kiln
bun install --frozen-lockfile
bun run kiln render examples/crate.kiln.js --out crate.glb --views sheet.png

--filter=blob:none checks out the current tree in full and leaves historical file contents on the server, fetching them only if you ask for an old revision. A plain git clone also works and gives you the whole history up front.

This writes a GLB and a six-view image of an existing program. It makes no model call. Rendering uses the CPU unless a compatible local GPU service is available. Use --render cpu to select the CPU explicitly. Sheets sit on a neutral grey; add --backdrop dark or --backdrop light when an asset's silhouette merges with it; kiln save takes the same flag for the preview it stores.

For anchored CLI edits, import source with kiln source asset.kiln.js, then run kiln edit RETURNED_REF --edits edits.json. The file contains an array of { "oldString": "exact existing text", "newString": "replacement text" } objects. The command returns a new immutable reference and diff without executing source; render that new reference to inspect the result. kiln edit --help describes batch limits and replaceAll.

Using assets in Blender or Unity? Read the handoff guide for direct GLB import, materials, backfaces, named pivots and animation checks. The established exporter remains the default. An experimental community exporter is available for explicit comparison when you need its additional feature preservation; the guide includes activation, rollback and known limitations. Both converters are included in this installation.

History was rewritten on 2026-09-10 to drop 288 MB of gallery renders and launch video that no tool reads, taking a clone from 440 MB to 60 MB, or 49 MB with --filter=blob:none; measured 2026-09-12. Every commit survived and the tree is unchanged apart from those files, but every commit hash changed, so a clone made before that date cannot fast-forward.

Re-cloning is simplest. Before converting an old clone, back up uncommitted work and local branches: the commands below reset the checkout and prune recovery history. Move the tag as well as the branch:

git fetch --tags --force origin
git reset --hard origin/main
git reflog expire --expire=now --all
git gc --prune=now

--force is the load-bearing flag. oss-2026-09-05 was rewritten too, and git will not move a tag that already exists without it: plain git fetch --tags, and even --prune-tags, both report would clobber existing tag and leave the old one in place, holding every removed file reachable. Omit it and .git stays at 228 MB where a fresh clone is 26 MB; run it and the same clone packs to 23 MB.

The gallery images are served from assets.kilnstudio.tools; the 83 poster receipts that attest their bytes stayed in examples/renders/.

Connect your agent

The agent reading guide links to setup, tool schemas and the source revision workflow in plain text.

The installation commands above create a separate asset workspace, register MCP and copy the Kiln skills. Follow its START.md to launch your harness. Setup writes project-local configuration and leaves your global settings unchanged. A user-level server named kiln