Generative UI Spec

The serializable node tree an assistant emits to describe generative UI. Covers the GenerativeUISpec format, its nodes, and the message part that carries the spec.

API Reference

GenerativeUIMessagePart

A message part that carries a JSON spec describing UI to render.

Render with <MessagePrimitive.GenerativeUI components={...} />. The primitive resolves component names against the consumer-provided allowlist — any unknown name throws a typed error rather than rendering. Stream- friendly: a partially-streamed spec renders progressively.

GenerativeUIMessagePart

type : "generative-ui"

spec : GenerativeUISpec

The JSON spec describing the UI tree.

root : GenerativeUINode | readonly GenerativeUINode[]: Root node(s) to render.

id ?: string

Optional id (useful for replays / stable keys).

parentId ?: string

GenerativeUINode

A JSON spec describing a tree of UI components to render.

The agent emits a GenerativeUIMessagePart containing this spec, and the consumer-provided component allowlist is used to resolve component names. Any component referenced that is not present in the allowlist is rejected with a typed error — the allowlist is the security boundary in the default same-realm rendering path.

GenerativeUINode

toString : (() => string) | (() => string)
valueOf : (() => string) | (() => Object)

GenerativeUISpec

The root spec for a generative UI tree.

GenerativeUISpec

root : GenerativeUINode | readonly GenerativeUINode[]: Root node(s) to render.