@molecule/app-ai-image-generator

AI image generation core interface for molecule.dev.

Defines the AIImageGeneratorProvider contract for prompt-to-image features: generate(request, config, onEvent) streams progress/image/done/error events and resolves with the generated images; loadHistory / deleteImage manage previously generated images; abort() cancels an in-flight generation.

Auto-generated, AI-first package reference for the molecule.dev ecosystem. It is written to be read by coding agents as much as by people, and is generated from this package's source — edit src/index.ts JSDoc, not this file.

Quick Start

import { requireProvider, setProvider } from '@molecule/app-ai-image-generator'
import { createProvider } from '@molecule/app-ai-image-generator-default'

setProvider(createProvider()) // at startup

const generator = requireProvider()
const images = await generator.generate(
  { prompt: 'A watercolor fox', size: '1024x1024', count: 1 },
  { endpoint: '/api/images/generate' },
  (event) => {
    if (event.type === 'progress') setProgress(event.percent)
    if (event.type === 'error') showError(event.message)
  },
)

Type

core

Installation

npm install @molecule/app-ai-image-generator @molecule/app-bond

API

Interfaces

ImageGenerationRequest

Request parameters for generating images.

interface ImageGenerationRequest {
  /** Text description of the desired image. */
  prompt: string
  /** Text description of elements to exclude from the image. */
  negativePrompt?: string
  /** Image dimensions as a preset string. */
  size?: ImageSize
  /** Number of images to generate (1–10). */
  count?: number
  /** Output image format. */
  format?: ImageFormat
  /** Quality preset. */
  quality?: ImageQuality
  /** Optional model identifier override. */
  model?: string
  /** Optional style preset (e.g. `'vivid'`, `'natural'`). */
  style?: string
}

GeneratedImage

A single generated image result.

interface GeneratedImage {
  /** Unique image identifier. */
  id: string
  /** URL to the generated image (may be temporary). */
  url: string
  /** The prompt that was used to generate this image. */
  prompt: string
  /** The revised/expanded prompt the model actually used, if different. */
  revisedPrompt?: string
  /** Image width in pixels. */
  width: number
  /** Image height in pixels. */
  height: number
  /** Creation timestamp (ms since epoch). */
  createdAt: number
}

ImageGenerationConfig

Configuration for image generation API requests.

interface ImageGenerationConfig {
  /** API endpoint path (e.g. `'/api/images/generate'`). */
  endpoint: string
  /** Default model to use for generation. */
  model?: string
}

AIImageGeneratorProvider

Provider interface for AI image generation.

Implement this in a bond package to provide a concrete image generation backend.

interface AIImageGeneratorProvider {
  /** Unique name identifying this provider implementation. */
  readonly name: string

  /**
   * Generates images from a text prompt.
   *
   * @param request - The generation parameters (prompt, size, count, etc.).
   * @param config - API endpoint and model configuration.
   * @param onEvent - Callback invoked for progress, image, done, and error events.
   * @returns The array of generated images on success.
   */
  generate(
    request: ImageGenerationRequest,
    config: ImageGenerationConfig,
    onEvent: ImageGenerationEventHandler,
  ): Promise<GeneratedImage[]>

  /**
   * Aborts the current in-flight generation request, if any.
   */
  abort(): void

  /**
   * Loads previously generated images from the server.
   *
   * @param config - API endpoint configuration.
   * @returns An array of previously generated images, newest first.
   */
  loadHistory(config: ImageGenerationConfig): Promise<GeneratedImage[]>

  /**
   * Deletes a previously generated image.
   *
   * @param id - The image ID to delete.
   * @param config - API endpoint configuration.
   */
  deleteImage(id: string, config: ImageGenerationConfig): Promise<void>
}

Types

ImageSize

Standard image size presets supported by most generation APIs.

type ImageSize = '256x256' | '512x512' | '1024x1024' | '1024x1792' | '1792x1024'

ImageFormat

Output image format.

type ImageFormat = 'png' | 'jpeg' | 'webp'

ImageQuality

Image generation quality preset.

type ImageQuality = 'standard' | 'hd'

ImageGenerationEvent

Events emitted during image generation.

• started — generation request accepted by the server.
• progress — intermediate progress update (percent complete).
• image — a single generated image is ready.
• done — all images have been generated.
• error — generation failed.

type ImageGenerationEvent =
  | { type: 'started' }
  | { type: 'progress'; percent: number; message?: string }
  | { type: 'image'; image: GeneratedImage }
  | { type: 'done'; images: GeneratedImage[] }
  | { type: 'error'; message: string }

ImageGenerationEventHandler

Callback invoked for each event during image generation.

type ImageGenerationEventHandler = (event: ImageGenerationEvent) => void

• event — The generation event.

Functions

setProvider(provider)

Registers the active image generator provider.

function setProvider(provider: AIImageGeneratorProvider): void

• provider — The provider implementation to bond.

getProvider()

Returns the bonded image generator provider, or null if none is set.

function getProvider(): AIImageGeneratorProvider | null

Returns: The active provider or null.

hasProvider()

Checks whether an image generator provider has been bonded.

function hasProvider(): boolean

Returns: true if a provider is configured.

requireProvider()

Returns the bonded image generator provider or throws if none is configured.

function requireProvider(): AIImageGeneratorProvider

Returns: The active provider.

Available Providers

Provider	Package
Ai Image Generator	@molecule/app-ai-image-generator-default

Injection Notes

Requirements

Peer dependencies:

• @molecule/app-bond ^1.0.1

Runtime Dependencies

• @molecule/app-bond

• Wire it with THIS package's setProvider() or bond('ai-image-generator', …). setProvider() delegates into the shared @molecule/app-bond registry, so both write the same slot; requireProvider() throws until one has run.

• Generation goes through YOUR backend (config.endpoint), which calls the image model server-side (see @molecule/api-ai-image-generation) — the vendor key never reaches the browser.

• GeneratedImage.url may be TEMPORARY (signed/expiring upstream URLs). If the app keeps a gallery, have the server download and persist the bytes (e.g. via the uploads package) and store YOUR url — storing the returned url alone ships dead links.

• count is bounded 1–10; generation is slow — drive the UI from the progress / image events rather than blocking on the promise alone.

E2E Tests

Integration checklist — drive the real UI (live preview, no mocks), adapt each item to this app's actual screens/flows, and check every box off one by one. A box you can't check is an integration bug to fix — not a skip:

• Entering a prompt and generating renders the resulting GeneratedImage(s) as real pixels on screen: the image / done events deliver objects whose url loads to a visible picture, not a broken or placeholder tile.
• A generating indicator shows while the request is in flight — driven by the started / progress (progress.percent) events — and clears when done fires and generate() resolves; it never spins forever.
• A generation failure surfaces visibly: the error event's message (provider failure, or a moderation-rejected prompt) renders as a message in the UI, never a silent no-op or a stuck spinner.
• When the request sets count > 1 (bounded 1–10), ALL requested images render — the done event's images array length matches what was asked, not just the first one.
• The request's size preset (e.g. '1024x1024' vs '1792x1024') is honored in the output: the rendered image's width / height match the requested dimensions rather than a default square.
• The generated image is usable downstream as the app wires it (insert / download / select), carrying the real GeneratedImage data (id, url); because url may be temporary, an image kept in a gallery still loads after a full reload — proving the app persisted the bytes, not a dead upstream link.
• Generations are scoped to the requesting user: loadHistory / the gallery returns only that user's own images, and a moderation-rejected prompt shows the rejection rather than a blank tile.