Host

For the application embedding a canvas, not for the environments in it: the document and scene hosts, and the adapters they are given for storage, code execution and plugins.

@internote/canvas-sdk@internote/canvas-sdk/host29 exports

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This area is for the application that shows documents, not for the environments in them.

CanvasDocumentHost, from @internote/canvas-sdk/host, draws one scene of a compiled document: its environments and other content in the order the author wrote them, one toolbar and one footer. Import @internote/canvas-sdk/styles once, alongside it.

import { CanvasDocumentHost } from '@internote/canvas-sdk/host';
import '@internote/canvas-sdk/styles';

<CanvasDocumentHost document={compiled} environments={[greetingEnvironment]} />

The host is given the services environments need: db for database-tier storage, and a CodeRunner for environments that run code. Leave one out and the environments that use it do without.

CanvasSceneView draws one scene of a host already mounted. Its footer says what goes under the canvas: scene, the whole footer; key, the scene's key and scales alone with no frame or controls, for a picture of the scene; or none. useSceneHasKey says whether key would draw anything.

createHeadlessCanvasHost takes two options for drawing a picture of a document someone is reading: seed, another host's session.snapshot(), so every environment starts where it stood there; and still, which tells every environment that nothing should play.

createHeadlessCanvasHost mounts a document with no React and no browser. It is what tests use, and what CanvasDocumentHost is built on.

loadEnvironmentFromManifest checks a plugin's manifest, loads its code and registers the environment it defines.

#Components

CanvasDocumentHost

Mounts a compiled document on a headless host and draws one of its scenes.

CanvasSceneView

Draws one scene of a headless host: one toolbar, the scene's blocks in source order, one footer.

#Hooks

Returns whether the scene has a key or a scale to show: what SceneKey would draw.

useStepRevision

Re-renders the calling component on every step change, and on each animation frame after it while the scene moves.

#Functions

createHeadlessCanvasHost

Mounts a compiled document without React or a DOM: step controllers, environment runtimes, session storage and toolbar resolution, exposed for direct use.

finalTrackValue

Returns the value a track ends on: its last frame's, or its base when it has none.

loadEnvironmentFromManifest

Validates a plugin manifest, imports its code and registers the environment it defines.

printedDocument

Returns a copy of document whose scenes' canvases are as a printed page draws them: no tasks, and settled when options.settle says so.

resolveCanvasLayout

Splits a compiled scene's detail into canvas environments and blank-canvas content, and reads the scene's direction and ratio.

resolveSplitDirection

Returns the concrete axis a split lays out on.

settledDocument

Returns a copy of document with its canvases settled for print: no tasks, every cue in, nothing emphasised, every !cue.to at its final value.

#Interfaces

Runs code for environments that run programs, injected by the host.

One program for a CodeRunner to run.

BlankRenderContext

What a blank-element renderer receives alongside the node.

A scene's canvas split into its environments, its blank-canvas content and the split's arrangement.

CanvasLayoutItem

One block of a scene's canvas: an environment, or an element of its blank-canvas content.

CanvasLoadOptions

How loadEnvironmentFromManifest imports and registers a plugin.

HeadlessCanvasHost

A mounted document: its scenes and environments, the shared session store and the semantic diagnostics.

HeadlessEnvironment

One mounted canvas environment in a headless host.

HeadlessHostOptions

What createHeadlessCanvasHost mounts and the services it hands each environment.

One scene of a mounted document: its step timeline, layout and environments.

HostPlaybackState

The playback control's state — null on a step with nothing to play, where the host draws no control at all.

HostToolbarState

Everything an embedder needs to draw the host toolbar.

PrintedCanvasOptions

How a printed canvas is drawn.

StepRevisionOptions

Options for useStepRevision.

#Types

CodeRunAvailability

Whether running is possible right now, and if not, why.

One frame of a run, in arrival order.

BlankElementRenderer

Draws one element of a scene's blank-canvas content (everything in the detail outside the canvas environments).

A split's direction as the author wrote it.

Last updated 26 September 2026