Iki
A rigged character rendered by the Iki engine, head turned slightly and smiling.

Every frame is just numbers you own.

Iki is an open 2D rig puppet animation engine for the web. You author a character as layered parts wired to parameters, and the runtime animates it in WebGL. The model is plain JSON — readable in a text editor, diffable in git, and small enough for a script to generate.

These sixteen values produced the frame above. That is the whole rig — a host drives the same ids from lip-sync, gaze, blink timers, and expressions.

ParamAngleX11.00
ParamAngleY−4.00
ParamAngleZ4.00
ParamBreath0.45
ParamMouthOpenY0.18
ParamMouthForm0.65
ParamEyeLOpen1.00
ParamEyeROpen1.00
ParamEyeBallX0.22
ParamEyeBallY0.05
ParamBrowLY0.25
ParamBrowRY0.25
ParamBrowLAngle0.00
ParamBrowRAngle0.00
ParamHairSwayX−6.00
ParamHairSwayZ3.00

What runs today

Iki is early, but none of this is a mockup — every line below is running in the two demos linked at the top of this page.

Runtime
Renders parameter-driven color quads, atlas-sampled texture parts, warp-mesh and grid deformation, stencil clipping masks, and spring and chain physics. WebGL2, no native toolchain.
Editor
Authors parts, deformers, and physics rigs in the browser, with undo and redo on every edit. Imports layered PSDs.
Generator
Rigs a character from role-named PNG or PSD layers — blink, gaze, mouth, head turn, and brows, wired automatically. It also runs as an MCP server, so an AI agent can take layers to a rigged model without a human in the loop.
Format
One documented schema with a fail-fast validator that reports the exact path that failed. A model is a .iki JSON file you can open, read, and edit by hand.

Packages

Published to npm under @ikijs. The engine depends only on the format package, and never on a host.

Package What it is
@ikijs/format The .iki model schema, types, loader, and validator
@ikijs/engine WebGL2 runtime that plays a model
@ikijs/editor Headless editing core — documents, commands, undo/redo, and the auto-rigger
@ikijs/mcp MCP server that exposes reading, validating, and rigging to agents

Live2D Cubism is the industry standard and is far more mature than Iki in every dimension that matters to an artist. If you need production-grade 2D rigging today, use Cubism. Iki exists for people who want an open web format they can script against — read the full comparison.