gpt-image-playground

GPT Image Playground

Skill by ara.so — Daily 2026 Skills collection.

A React 19 + TypeScript + Vite web application for generating and editing images via OpenAI's Images API (/v1/images) or Responses API (/v1/responses). Features a responsive UI with waterfall task cards, IndexedDB local storage, PWA support, bulk selection, history management, and ZIP export/import.

---

What It Does

• Text-to-image: Generate images from prompts via images/generations or responses with image_generation tool
• Reference image editing: Upload up to 16 reference images, call images/edits or multimodal Responses API
• Smart size selector: Auto-calculates resolutions for 1K/2K/4K at common aspect ratios; custom sizes auto-snapped to 16px multiples, max 3840px, max ratio 3:1, pixel range 655360–8294400
• Parameter control: Quality (low/medium/high), format (PNG/JPEG/WebP), compression, moderation level
• History: IndexedDB storage with SHA-256 image deduplication, bulk ops, favorites, search/filter
• Data portability: ZIP export/import with raw image files + manifest.json

---

Tech Stack

Layer	Technology
Framework	React 19 + TypeScript
Build	Vite
Styling	Tailwind CSS 3
State	Zustand
Storage	Browser IndexedDB API

---

Installation & Setup

Prerequisites

• Node.js 18+
• npm

Clone and Run Locally

git clone https://github.com/CookSleep/gpt_image_playground.git
cd gpt_image_playground
npm install
npm run dev
# Visit http://localhost:5173

Environment Variables

Create .env.local in the project root:

# Optional: pre-fill default API URL at build time
VITE_DEFAULT_API_URL=https://api.openai.com/v1

Build for Production

npm run build
# Output in dist/ — deploy to any static file server

Docker

# Single container
docker run -d -p 8080:80 \
  -e API_URL=https://api.openai.com/v1 \
  ghcr.io/cooksleep/gpt_image_playground:latest

# Docker Compose
cat > docker-compose.yml << 'EOF'
services:
  gpt-image-playground:
    image: ghcr.io/cooksleep/gpt_image_playground:latest
    environment:
      - API_URL=https://api.openai.com/v1
    ports:
      - "8080:80"
    restart: unless-stopped
EOF
docker compose up -d

Update to latest:

docker compose pull && docker compose up -d

---

Vercel One-Click Deploy

Add environment variable in Settings → Environment Variables:

VITE_DEFAULT_API_URL=https://api.openai.com/v1

---

API Configuration

In-App Settings

Open settings (top-right gear icon) and configure:

Field	Images API	Responses API
Endpoint	/v1/images/generations, /v1/images/edits	/v1/responses
Model example	gpt-image-1	gpt-4o, gpt-5.5

URL Query Parameters (Deep-link Config)

Pre-fill settings via URL — useful for bookmarks or sharing:

https://gpt-image-playground.cooksleep.dev?apiUrl=https://your-proxy.com&apiKey=sk-xxxx
https://cooksleep.github.io/gpt_image_playground?apiUrl=https://your-proxy.com&apiKey=sk-xxxx

Parameters:

• apiUrl — API base URL
• apiKey — OpenAI API key

---

Local Development Proxy (CORS Bypass)

When your API endpoint doesn't allow browser CORS, use the Vite dev proxy:

cp dev-proxy.config.example.json dev-proxy.config.json

Edit dev-proxy.config.json:

{
  "enabled": true,
  "prefix": "/api-proxy",
  "target": "http://127.0.0.1:3000",
  "changeOrigin": true,
  "secure": false
}

Request flow:

Browser → http://localhost:5173/api-proxy/v1/images/generations
       → Vite proxy forwards to →
         http://127.0.0.1:3000/v1/images/generations

Note: Proxy only works with npm run dev. Not included in production builds.

Set API URL in the app settings to match target. The app rewrites matching requests to use the proxy prefix.

If target or API URL already includes /v1, the path won't be duplicated — requests become /api-proxy/responses not /api-proxy/v1/responses.

---

Key Source Code Patterns

Project Structure

src/
├── components/          # React UI components
├── hooks/               # Custom React hooks
├── store/               # Zustand state stores
├── utils/               # Helpers (IndexedDB, image processing, etc.)
├── types/               # TypeScript type definitions
└── main.tsx             # App entry point

Using the Images API Directly (TypeScript)

// Pattern matching how the app calls OpenAI Images API
async function generateImage(params: {
  prompt: string;
  model: string;
  size: string;
  quality: "low" | "medium" | "high";
  n: number;
  outputFormat: "png" | "jpeg" | "webp";
  outputCompression?: number;
  apiKey: string;
  apiUrl: string;
}) {
  const response = await fetch(`${params.apiUrl}/images/generations`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${params.apiKey}`,
    },
    body: JSON.stringify({
      model: params.model,
      prompt: params.prompt,
      n: params.n,
      size: params.size,
      quality: params.quality,
      output_format: params.outputFormat,
      ...(params.outputFormat !== "png" && {
        output_compression: params.outputCompression,
      }),
    }),
  });

  if (!response.ok) {
    const error = await response.json();
    throw new Error(error.error?.message ?? "Generation failed");
  }

  return response.json();
}

Using the Images Edit API with Reference Images

async function editImage(params: {
  prompt: string;
  images: File[];
  model: string;
  size: string;
  quality: "low" | "medium" | "high";
  n: number;
  apiKey: string;
  apiUrl: string;
}) {
  const formData = new FormData();
  formData.append("model", params.model);
  formData.append("prompt", params.prompt);
  formData.append("n", String(params.n));
  formData.append("size", params.size);
  formData.append("quality", params.quality);

  // Up to 16 reference images
  params.images.forEach((file) => {
    formData.append("image[]", file);
  });

  const response = await fetch(`${params.apiUrl}/images/edits`, {
    method: "POST",
    headers: {
      Authorization: `Bearer ${params.apiKey}`,
      // Do NOT set Content-Type — browser sets multipart boundary automatically
    },
    body: formData,
  });

  return response.json();
}

Using Responses API with image_generation Tool

async function generateViaResponsesAPI(params: {
  prompt: string;
  model: string;
  size: string;
  quality: "low" | "medium" | "high";
  apiKey: string;
  apiUrl: string;
}) {
  const response = await fetch(`${params.apiUrl}/responses`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${params.apiKey}`,
    },
    body: JSON.stringify({
      model: params.model,
      input: params.prompt,
      tools: [
        {
          type: "image_generation",
          size: params.size,
          quality: params.quality,
        },
      ],
    }),
  });

  return response.json();
}

Custom Size Validation (matches app logic)

function sanitizeImageSize(width: number, height: number): {
  width: number;
  height: number;
} {
  // Snap to 16px multiples
  let w = Math.round(width / 16) * 16;
  let h = Math.round(height / 16) * 16;

  // Max edge 3840px
  const maxEdge = 3840;
  if (w > maxEdge) w = maxEdge;
  if (h > maxEdge) h = maxEdge;

  // Aspect ratio must not exceed 3:1
  if (w / h > 3) h = Math.ceil(w / 3 / 16) * 16;
  if (h / w > 3) w = Math.ceil(h / 3 / 16) * 16;

  // Total pixels: 655360 to 8294400
  const pixels = w * h;
  const minPixels = 655360;
  const maxPixels = 8294400;

  if (pixels < minPixels) {
    const scale = Math.sqrt(minPixels / pixels);
    w = Math.ceil((w * scale) / 16) * 16;
    h = Math.ceil((h * scale) / 16) * 16;
  }

  if (pixels > maxPixels) {
    const scale = Math.sqrt(maxPixels / pixels);
    w = Math.floor((w * scale) / 16) * 16;
    h = Math.floor((h * scale) / 16) * 16;
  }

  return { width: w, height: h };
}

Adding IndexedDB Storage (pattern used by the app)

import { openDB, IDBPDatabase } from "idb"; // App uses native IDB API directly

const DB_NAME = "gpt-image-playground";
const DB_VERSION = 1;

async function initDB(): Promise<IDBDatabase> {
  return new Promise((resolve, reject) => {
    const request = indexedDB.open(DB_NAME, DB_VERSION);

    request.onupgradeneeded = (event) => {
      const db = (event.target as IDBOpenDBRequest).result;
      // Tasks store
      if (!db.objectStoreNames.contains("tasks")) {
        const tasks = db.createObjectStore("tasks", { keyPath: "id" });
        tasks.createIndex("createdAt", "createdAt");
        tasks.createIndex("status", "status");
        tasks.createIndex("favorited", "favorited");
      }
      // Images store with SHA-256 hash deduplication
      if (!db.objectStoreNames.contains("images")) {
        db.createObjectStore("images", { keyPath: "hash" });
      }
    };

    request.onsuccess = () => resolve(request.result);
    request.onerror = () => reject(request.error);
  });
}

Zustand Store Pattern (matching app architecture)

import { create } from "zustand";
import { persist } from "zustand/middleware";

interface SettingsStore {
  apiKey: string;
  apiUrl: string;
  apiMode: "images" | "responses";
  model: string;
  setApiKey: (key: string) => void;
  setApiUrl: (url: string) => void;
  setApiMode: (mode: "images" | "responses") => void;
  setModel: (model: string) => void;
}

const useSettingsStore = create<SettingsStore>()(
  persist(
    (set) => ({
      apiKey: "",
      apiUrl: "https://api.openai.com/v1",
      apiMode: "images",
      model: "gpt-image-1",
      setApiKey: (apiKey) => set({ apiKey }),
      setApiUrl: (apiUrl) => set({ apiUrl }),
      setApiMode: (apiMode) => set({ apiMode }),
      setModel: (model) => set({ model }),
    }),
    { name: "gpt-image-settings" }
  )
);

---

Common Workflows

1. Fork & Customize for a Specific Use Case

git clone https://github.com/CookSleep/gpt_image_playground.git
cd gpt_image_playground

# Set default API
echo "VITE_DEFAULT_API_URL=https://your-proxy.com/v1" > .env.local

npm install && npm run dev

2. Add a Custom Preset Size

In the size selector component, add to the presets array:

const SIZE_PRESETS = [
  // existing presets...
  {
    label: "Banner 16:5",
    ratio: { w: 16, h: 5 },
    resolutions: {
      "1K": { width: 1024, height: 320 },
      "2K": { width: 2048, height: 640 },
    },
  },
];

3. Extend Task History with Custom Metadata

interface TaskRecord {
  id: string;
  createdAt: number;
  prompt: string;
  status: "pending" | "success" | "failed";
  favorited: boolean;
  parameters: {
    model: string;
    size: string;
    quality: string;
    n: number;
    outputFormat: string;
  };
  // Add custom fields:
  tags?: string[];
  projectId?: string;
  outputImages: string[]; // SHA-256 hashes referencing images store
}

4. Export/Import Data Programmatically

The app exports a ZIP containing:

• Raw image files (not base64)
• manifest.json with task records and image metadata

// manifest.json structure
interface ExportManifest {
  version: string;
  exportedAt: string;
  tasks: TaskRecord[];
  images: {
    hash: string;
    filename: string;
    mimeType: string;
    size: number;
  }[];
}

---

Troubleshooting

CORS Errors in Browser

Cause: API endpoint doesn't allow browser cross-origin requests.

Fix (dev): Enable local proxy in dev-proxy.config.json (see above).

Fix (production): Use a server-side proxy (Vercel Functions, Cloudflare Workers, or Nginx proxy_pass).

.dev Domain HTTPS Requirement

The gpt-image-playground.cooksleep.dev deployment requires all resources to be HTTPS. If your API is HTTP-only, use the GitHub Pages version:

https://cooksleep.github.io/gpt_image_playground

Custom Size Not Accepted by API

Ensure size passes validation:

• Width and height are multiples of 16
• Neither dimension exceeds 3840px
• Aspect ratio ≤ 3:1
• Total pixels between 655,360 and 8,294,400

Use the sanitizeImageSize function above to auto-correct.

Responses API vs Images API

Scenario	Use
Direct image generation	Images API + gpt-image-1
Codex CLI-derived APIs	Responses API
Text model + image tool	Responses API + text model (e.g. gpt-4o)
images/edits for multi-image input	Images API only

Docker: API URL Not Pre-filled

Ensure you pass the env variable at runtime (not build time):

docker run -e API_URL=https://api.openai.com/v1 ...

The container's entrypoint injects API_URL into the Nginx-served static files at startup.

IndexedDB Orphaned Images

The app automatically cleans up orphaned image blobs on startup. If storage grows unexpectedly, use the in-app export → clear data → reimport workflow, or manually clear IndexedDB via DevTools → Application → IndexedDB.

---

Live Deployments

Version	URL
Vercel (HTTPS only)	https://gpt-image-playground.cooksleep.dev
GitHub Pages	https://cooksleep.github.io/gpt_image_playground