Obsidian Canvas JSON format (TypeScript definition)

canvas.ts

export type Side = 'top' | 'right' | 'bottom' | 'left';

export interface CanvasData {
    nodes: (CanvasFileData | CanvasTextData | CanvasLinkData)[];
    edges: CanvasEdgeData[];
}

export interface CanvasNodeData {
    id: string;
    x: number;
    y: number;
    width: number;
    height: number;
    color: string;
}

export interface CanvasEdgeData {
    id: string;
    fromNode: string;
    fromSide: Side;
    toNode: string;
    toSide: Side;
    color: string;
    label: string;
}

export interface CanvasFileData extends CanvasNodeData {
    type: 'file';
    file: string;
}

export interface CanvasTextData extends CanvasNodeData {
    type: 'text';
    text: string;
}

export interface CanvasLinkData extends CanvasNodeData {
    type: 'link';
    url: string;
}

Taken from Licat on Discord:
https://discord.com/channels/686053708261228577/716028884885307432/1049422491560452186

Official TypeScript declaration file:
https://github.com/obsidianmd/obsidian-api/blob/master/canvas.d.ts