AI Image Generator

Generate PNG images from text prompts using Workers AI and the @cf/black-forest-labs/flux-1-schnell model at the edge.

FeaturesCopy Anchor Link

• Generate PNG images from text prompts at the edge
• Workers AI image model (@cf/black-forest-labs/flux-1-schnell)
• Returns binary image responses directly from the Worker
• No external image API keys required

API ReferenceCopy Anchor Link

GET /generateCopy Anchor Link

Generates a PNG image from the provided text prompt.

Example RequestCopy Anchor Link

curl "https://your-worker.workers.dev/generate?prompt=a%20sunset%20over%20snow-capped%20mountains" \
  --output image.png

Success ResponseCopy Anchor Link

Returns a PNG image with the following header:

Content-Type: image/png

Error ResponseCopy Anchor Link

{
  "error": "Missing or invalid query parameter: prompt",
  "code": "INVALID_PROMPT"
}

Error CodesCopy Anchor Link

• 400 - Missing or invalid prompt (INVALID_PROMPT)
• 502 - Workers AI model run failed (AI_ERROR)

Use CasesCopy Anchor Link

• Prototype AI image generation without external API keys
• Generate placeholder or marketing visuals from text at the edge
• Learn Workers AI image models in a stateless Worker
• Build creative tools that return binary image responses directly

LimitationsCopy Anchor Link

• Workers AI image generation is subject to usage limits by plan
• Fixed model and parameters; no style, size, or batch controls in this experiment
• Returns a single PNG per request; no async jobs or storage
• Public endpoint with no authentication or rate limiting

Use in your projectCopy Anchor Link

import type { Env } from "../types/env";import { AI_MODEL } from "../constants/defaults";type ImageResult = {  image?: string;};export async function generateImage(env: Env, prompt: string): Promise<Uint8Array> {  const out = (await env.AI.run(AI_MODEL, { prompt })) as ImageResult;  if (!out.image) {    throw new Error("Image model returned no image");  }  const binaryString = atob(out.image);  return Uint8Array.from(binaryString, (m) => m.codePointAt(0) ?? 0);}

DeploymentCopy Anchor Link

curl "https://your-worker.workers.dev/generate?prompt=a%20sunset%20over%20snow-capped%20mountains" \
  --output image.png

Local DevelopmentCopy Anchor Link

cd apps/experiments/ai-image-generator
npm install
npm run dev

Test locally:

curl "http://localhost:8787/generate?prompt=a%20cyberpunk%20cityscape" \
  --output image.png

Cloudflare Features UsedCopy Anchor Link

• Workers - Edge compute runtime
• Workers AI - @cf/black-forest-labs/flux-1-schnell image generation model