🧪 SpriteBrew

AI-powered pixel art sprite sheet generator. Generate characters from text → animate → slice → preview → export game-ready sheets for Unity, Godot, GameMaker, RPG Maker.

Status: Live in production · Active development · Real customers brewing daily

🌐 spritebrew.com — Try it now (free account = 5 generation tokens to start)

What is SpriteBrew?

SpriteBrew is a web-based tool for indie game developers that combines traditional sprite sheet workflows with AI-powered generation. Create new characters from text descriptions across 21 visual styles, animate existing pixel art, preview animations with full keyboard controls, and export to every major game engine — all in one place.

Free tools (no account needed): Upload & Slice, Animation Preview, Multi-Engine Export, Pixel Editor, Pixel-Perfect Resizer.

AI features (free account, token-based): Text-to-Sprite Generation across 21 styles, Animate My Character. Free signup bonus + daily login rewards. Token packs start at $4.99 for users who want more.

Features

🎨 AI Sprite Generation

Describe a character in plain text and pick from 21 visual styles across 5 categories: characters (Pro Fantasy, Sci-fi, Horror, Painterly, Simple, Default, Top Down, Platformer), tiles (Isometric, Hexagonal, Spritesheet, Dungeon Map), UI elements (Typography, FPS Weapon, Skill / Spell Icon, UI Panel, Inventory Items), and animation styles (4-Angle Walking, Walking & Idle, Small Sprites, VFX Effects, Custom Animation, 8-Direction Rotation). Each style has its own tier (Fast / Plus / Pro / Animation) with token cost scaled to model complexity. Powered by Retro Diffusion's pixel art models via direct API.

🖼️ Per-Style Example Lightbox

Tap the ⤢ icon on any style card to open a carousel showing what each style actually produces — 2-5 curated examples per style. Pick what you actually want, not what you think a style means by name. "Use this style →" in the lightbox toolbar selects + closes in one click.

🌅 Persistent Background Toggle

The "Remove background" control sits on the sticky generate bar — always visible during the entire generation flow. Defaults intelligently per style category (on for characters, off for tiles). Toggle off to keep environmental detail in your generations.

🏃 Animate My Character

Upload your existing pixel art character and generate animation frames from it. Walk cycles, idle loops, attacks, jumps, crouches, subtle motion, and custom actions — the AI preserves your character's appearance while creating smooth motion. Smart animation padding ensures weapons and motion aren't clipped.

🧙 Auto-Prep Character Pipeline

Drop any character image and SpriteBrew handles the rest: contour-based sprite detection, smart cropping, background removal with adjustable tolerance, and pixel-perfect resize to 64×64. Before/after preview with one-click approval. Edit the prepped image in the built-in pixel editor if auto-detection missed something.

✂️ Upload & Slice

Drop any sprite sheet PNG, configure frame dimensions (auto-detect or manual), and slice it into individual frames. Grid overlay preview, multi-select frames, contour-based detection for non-grid layouts, and smart auto-assignment of animation groups with directional detection.

🎮 Animation Preview

PixiJS-powered interactive demo area with full keyboard controls. Walk your character around with arrow keys, trigger attacks with spacebar, and test animations in real-time. Supports 4-directional movement for top-down RPG sprites. Multiple tiled backgrounds (grid, grass, dungeon, stone).

📦 Multi-Engine Export

Export to six formats in one click:

• TexturePacker JSON Hash (Unity, Godot, general)
• Aseprite JSON (pixel art workflow)
• GameMaker horizontal strips
• RPG Maker MV/MZ 3×4 grid
• Godot SpriteFrames .tres
• Raw Frames ZIP (individual PNGs)

🖌️ Pixel Editor

Click any frame to open a zoomed pixel editor. Fix AI artifacts, touch up details, or make manual adjustments. Pencil, eraser, eyedropper, color palette, undo/redo (50 states, Ctrl+Z). Edit at 8-16× zoom with pixel grid overlay and 1× preview alongside.

📸 Generation Gallery

Browse all past generations with filtering (Created vs Animated). Download PNGs, send to slicer, or delete. Per-user history — each account sees only their own generations.

🪙 Token Economy

Free users get 5 tokens at signup, +3 tokens every daily login, and a +6 bonus on every 7th consecutive day. Subscribe to the newsletter for +5 more. Token packs start at $4.99 for users who want to brew more. Generation costs: Fast 3 / Plus 10 / Pro 40 / Anim-short 15 / Anim-long 50 tokens.

📐 Pixel-Perfect Image Resizer

Built-in nearest-neighbor resizing for preparing pixel art for animation. Upload a high-res character, resize to 64×64 with crisp pixel-perfect scaling — no blurry bilinear interpolation.

🔐 Authentication

Sign in with Google or email via Clerk. Free tools work without an account. AI generation requires a free login. Production SSO, bot-signup protection enabled.

Tech Stack

Architecture Highlights

• Queue-and-poll architecture for long-running AI generations. Producer enqueues to Cloudflare Queues, consumer Worker calls Retro Diffusion out-of-band, browser polls /api/generation-status/{jobId} every ~2-3 seconds. Sidesteps Cloudflare's 120-second proxy timeout entirely. Tokens auto-refund on generation failure.
• Token economy backed by Cloudflare KV with server-side debiting and idempotency-keyed refunds.
• Server-side free-tier caps (10 Pro / 30 Fast lifetime per non-paying account) — paid accounts uncapped.
• Stripe webhooks for payment processing with signature verification and replay protection.
• Contour-based sprite detection using connected component labeling for non-grid sprite sheets.
• Recon-first development methodology — when wiring up a new API, library, or feature, read existing code paths and verify assumptions before implementation. Caught at least one architectural misconception per major feature so far.

Getting Started (Development)

# Clone the repo
git clone https://github.com/GAlbanese09/spritebrew.git
cd spritebrew

# Install dependencies
npm install

# Set up environment variables
cp .env.example .env.local

Add your API keys to .env.local:

NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_test_...
CLERK_SECRET_KEY=sk_test_...
CLERK_WEBHOOK_SECRET=whsec_...
NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=pk_test_...
STRIPE_SECRET_KEY=sk_test_...
STRIPE_WEBHOOK_SECRET=whsec_...
RETRO_DIFFUSION_API_KEY=rdp_...
RESEND_API_KEY=re_...
RESEND_AUDIENCE_ID=...
APP_ENV=dev
QUEUE_KICKOFF_ENABLED=true

# Run development server
npm run dev

Open http://localhost:3000 to see the app.

Note on local dev: The full app stack (queue-and-poll, Stripe webhooks, KV bindings) requires a Cloudflare Pages preview deployment to fully exercise. Local npm run dev is best for UI iteration; for end-to-end testing, push to a dev branch and let Cloudflare deploy a preview.

The consumer Worker that processes the queue lives in a sibling repo: spritebrew-rd-consumer.

The Story

SpriteBrew exists because a friend was building a pixel art game and needed sprite sheets. Making them by hand is brutally slow — every frame, every direction, every animation state, hand-drawn. There had to be a better way.

What started as a weekend project to help one friend turned into a production tool used by indie game developers worldwide. Pricing kept honest at token-based packs starting at $4.99 (no subscriptions). Real customers, real generations, real games getting made.

Built by George Albanese — an endpoint automation engineer by day, solo indie developer by night. Built with Claude as architect, research partner, and rubber duck through every session.

Roadmap

Done:

• [x] Phase 1: Web shell, sprite slicer, multi-engine export (6 formats)
• [x] Phase 2: AI integration via Retro Diffusion direct API (21 styles across 5 categories)
• [x] Phase 3: Production launch — Clerk auth, Stripe payments, token economy
• [x] Queue-and-poll architecture (replaces SSE streaming)
• [x] Per-style example lightbox previews
• [x] Persistent background toggle on sticky bar

In progress / on the roadmap:

• [ ] Animation style example previews (animated WebP)
• [ ] Client-side download upscaler (1× / 2× / 4× nearest-neighbor)
• [ ] DIY status page surfacing SpriteBrew + Retro Diffusion upstream health
• [ ] KV-backed feature kill switch (sub-60-second rollback path)
• [ ] Privacy Policy / Terms of Service / Refund Policy
• [ ] Public sprite gallery on landing page
• [ ] Subscription plans (Pixel Pass)
• [ ] OpenNext migration (replace deprecated @cloudflare/next-on-pages)
• [ ] Isometric sprite tooling beyond the existing isometric style
• [ ] Tauri desktop app

Acknowledgments

• Retro Diffusion — pixel art image generation models that power SpriteBrew's generation pipeline.
• Clerk — authentication without the pain
• Stripe — payments and customer management
• Cloudflare — Pages, Queues, KV, and the infrastructure that keeps this running on a hobby budget
• PixiJS — the rendering engine behind the animation preview
• Purelymail — transactional email at indie-budget pricing
• Resend — audience and newsletter delivery
• Claude (Anthropic) — architect, research partner, prompt writer, rubber duck
• George's friend @mohammadsalim — the reason this exists in the first place

License

AGPL-3.0 — Open source with SaaS protection. You can use, modify, and distribute SpriteBrew, but if you deploy a modified version as a service, you must release your changes under the same license.

Contributing

SpriteBrew is live in production and actively developed. If you're interested in contributing, please open an issue first to discuss what you'd like to work on. A Contributor License Agreement (CLA) will be required before merging PRs.

Bug reports, feature suggestions, and feedback are welcome via GitHub Issues or the in-app feedback form.

Built with ☕ and Claude · spritebrew.com · @spritebrew