An infinite canvas runtime for AI‑generated web artifacts.

Lifecycle

Resources follow the viewport, not the document count

Every artifact moves through an explicit state machine. Live DOM, runtimes, and GPU textures are budgeted resources granted by visibility and interaction — never ambient.

• Transitions are transactions. Allocation happens before publication; a fault leaves the previous committed scene usable.
• Snapshots stay selectable. A texture is one revision of paint output — the interaction tree keeps internal hit testing alive without live DOM.
• Stale runtimes can't write. Revision and epoch checks reject late messages from replaced runtimes before they touch the store.

Streaming

Built for content that is still being written

An agent emits an artifact token by token. Every kind commits at its own boundary — a grapheme, a line, a closed markdown construct, a JSON value, a decided HTML tag — and that boundary only ever moves forward, so a reader never sees an interpretation get retracted.

• Nothing half-parsed reaches the screen. A partial tag, an unterminated raw-text element, or an open code fence stays outside the boundary until the stream proves what it is.
• Provisional paint is not authoritative. A streaming artifact is pinned against eviction, shows provisional frames, and commits exactly one source revision when it finishes.
• The scene streams too. Frames appear and join the spatial index while their content is still arriving, so hit testing and visibility sets work mid-generation.
• Every kind has three presentations. Content, loading, and failed. An artifact is loading until its first character commits, media is atomic and only ever loads or fails, and a failure shows its reason beside the code you would quote in a bug report.

Packages

Backend-independent contracts, tested against oracles

Optimized implementations ship next to naive reference implementations and are differentially tested against them — the oracle stays available as a rollback path.