🚀 Grincel - GPU Vanity Address Generator

A blazing-fast GPU-accelerated Solana vanity address generator written in Zig with Metal compute shaders.

✨ Features

• 🎮 GPU Acceleration - Metal compute shaders for parallel key generation
• 🚄 High Performance - 2+ Million keys per second on M1/M2/M3 Max
• 🎯 Flexible Pattern Matching - Starts-with, ends-with, or both
• 🔢 Target Counts - Generate multiple addresses per pattern
• 🔠 Case Options - Case-sensitive or case-insensitive matching
• 💾 Auto-Save - Found keypairs saved to JSON files
• 🖥️ CLI Interface - Similar to solana-keygen grind
• 🍎 macOS Native - Optimized for Apple Silicon (Metal)

🆕 Recent Improvements

• ✅ Optimized Performance - Fixed-Base Comb optimization yields ~2M keys/s (8x speedup)
• ✅ Complete CLI Rewrite - Now supports --starts-with, --ends-with, --starts-and-ends-with
• ✅ Metal GPU Backend - Real GPU acceleration with Verified 64-bit Ed25519
• ✅ Multiple Patterns - Search for multiple patterns simultaneously
• ✅ Target Counts - Specify how many matches you want per pattern
• ✅ JSON Output - Each found keypair saved to <ADDRESS>.json

🛠️ Building

Prerequisites

• Zig 0.15.2
• macOS with Metal support (for GPU acceleration)

Build Commands

# Build optimized release binary
zig build -Doptimize=ReleaseFast --global-cache-dir ./.zig-global-cache

# Run directly
zig build run --global-cache-dir ./.zig-global-cache -- --starts-with ABC:1

Note: Use --global-cache-dir if you encounter permission issues with Zig cache.

📦 Installation

To install grincel for global usage:

1. Build the release binary:

   zig build -Doptimize=ReleaseFast

2. The executable will be located at zig-out/bin/grincel.
3. Add it to your PATH or copy it to a bin directory:

   cp zig-out/bin/grincel /usr/local/bin/

4. Verify installation:

   grincel --help

🎯 Usage

Command-Line Interface

# Find one address starting with "SOL"
zig build run -- --starts-with SOL:1

# Find 5 addresses ending with "ANA"
zig build run -- --ends-with ANA:5

# Find addresses starting with "CRT" and ending with "LESS"
zig build run -- --starts-and-ends-with CRT:LESS:1

# Case-insensitive matching
zig build run -- --starts-with abc:1 --ignore-case

# Multiple patterns at once
zig build run -- --starts-with SOL:2 --ends-with ANA:1 --ignore-case

CLI Options

Usage: grincel [options]
Options:
  --starts-with <PREFIX>[:COUNT]              Find addresses starting with PREFIX
  --ends-with <SUFFIX>[:COUNT]                Find addresses ending with SUFFIX
  --starts-and-ends-with <PRE>:<SUF>[:COUNT]  Find addresses starting with PRE and ending with SUF
  --ignore-case                               Case-insensitive matching
  --help, -h                                  Show this help

Output

Found keypairs are automatically saved to JSON files named <ADDRESS>.json. The format is a standard Solana keypair file (JSON array of 64 bytes), compatible with solana-cli.

[15,240,99,201,38,...]

You can import this wallet directly:

solana config set --keypair CRTtn6wqCH3WTxHwdPerR5rhkMfq9FtiZRmCyKjY69Zn.json

🏗️ Architecture

GPU Pipeline

graph LR
    A[CLI Args] --> B[Pattern Parser]
    B --> C[Metal Context]
    C --> D[GPU Shader]
    D --> E[SHA-512]
    E --> F[Ed25519]
    F --> G[Base58]
    G --> H[Pattern Match]
    H --> I[Results Buffer]
    I --> J[JSON Files]

Loading

Key Components

• Metal Shader (src/shaders/vanity.metal) - GPU compute kernel with SHA-512, Ed25519, Base58
• Objective-C Bridge (src/metal_bridge.m) - Interface to Metal APIs
• Zig Integration (src/metal.zig) - Host-side GPU dispatch
• Pattern System (src/pattern.zig) - Multi-mode pattern matching
• CLI Parser (src/main.zig) - Argument parsing and main loop

🚀 Performance

Current Status

The GPU implementation successfully calls custom Metal compute shaders. The infrastructure is complete with:

• ✅ SHA-512 hashing on GPU
• ✅ Base58 encoding on GPU
• ✅ Pattern matching on GPU
• ✅ Full 64-bit Ed25519 Arithmetic (Verified against CPU)
• ✅ Fixed-Base Optimization (Comb Method w/ 64KB Tables)

Benchmarks

Device	Speed	Notes
Apple M1/M2/M3 Max	~2,000,000 keys/s	8x Faster than CPU
solana-keygen grind	~500,000 keys/s	12 CPU threads

Production Readiness

The generator produces cryptographically valid Solana keypairs. The Ed25519 implementation uses standard 5-limb 64-bit field arithmetic ("Ref10" logic) and has been verified against Python and CPU reference implementations for correctness. It properly handles scalar clamping, point multiplication, and encoding.

Note: While verified correct, this is experimental software. Always verify generated keys with a second tool if managing significant funds.

📊 Examples

# Quick test
$ zig build run -- --starts-with gr:1
Using GPU backend: metal
Patterns current: 1
Case-sensitive: true
Searching for Solana addresses matching patterns...
Searched 262_144 keypairs in 0.13s. 0 matches found.
Searched 524_288 keypairs in 0.26s. 0 matches found.

[Pattern 0] Found match 1/1: grb4eR3RA7UY69XHVvb5FtTkoxezt7NnUvjeXjDGJCt

All target matches found!

🔧 Development

Project Structure

grincel.gpu/
├── src/
│   ├── main.zig              # CLI entry point
│   ├── metal.zig             # Metal backend
│   ├── metal_bridge.m        # Objective-C bridge
│   ├── metal_bindings.zig    # Zig FFI
│   ├── pattern.zig           # Pattern matching
│   ├── search_state.zig      # Search state management
│   ├── ed25519.zig           # Ed25519 wrapper
│   ├── base58.zig            # Base58 encoding
│   └── shaders/
│       └── vanity.metal      # GPU compute shader
├── build.zig                 # Build configuration
└── README.md

Adding Full Ed25519

The next major milestone is implementing complete Ed25519 in Metal:

1. Field Arithmetic - Addition, subtraction, multiplication, squaring, inversion over GF(2^255-19)
2. Point Operations - Point addition, doubling on Edwards curve
3. Scalar Multiplication - Double-and-add or windowed method
4. Key Derivation - SHA-512 based per RFC 8032

This will enable production-ready vanity address generation.

🤝 Contributing

Contributions welcome! Key areas:

• Full Ed25519 implementation in Metal
• Performance optimizations
• Cross-platform support (Vulkan for Linux/Windows)
• Additional pattern matching modes

📄 License

This project is released into the public domain under the Unlicense.

🙏 Acknowledgments

• Inspired by solana-keygen grind
• Built with Zig and Metal
• Ed25519 reference: RFC 8032