World Chain is a blockchain designed for humans. Built on the OP Stack and powered by reth, World Chain prioritizes scalability and accessibility for real users, providing the rails for a frictionless onchain UX.

Verified World ID holders receive priority access to blockspace, ensuring everyday users can transact even during peak network demand. PBH uses zero-knowledge proofs to verify humanity without revealing identity.

How it works:

• Top-of-block priority for verified humans
• Monthly transaction quotas with date-based rate limiting
• Semaphore ZK proofs for privacy-preserving verification
• Reserved blockspace capacity ensures network accessibility

📖 PBH Specification | Architecture

A high-speed execution lane that gives builders low-latency settlement for experiences like gaming, social, and real-time commerce. Flashblocks provides sub-second confirmation times for time-sensitive applications.

We use a home baked p2p flashblocks distribution mechanism by adding an additional rlpx sub protocol to the exisiting devp2p layer. Read more here!

📦 Flashblocks Implementation

World Chain extends the OP Stack with custom transaction ordering and validation:

• Priority Blockspace for Humans: Set of crates for World specific functionality
• Flashblocks: Set of crates that make up flashblocks components
• Smart Contracts: Solidity contracts for PBH validation

• Rustup
• Foundry (for smart contracts)
• Just (task runner)

# Clone the repository
git clone https://github.com/worldcoin/world-chain.git
cd world-chain

# Build the node
cargo build --release

# Run tests
cargo test

Use Kurtosis for local development and testing:

just devnet-up

See devnet documentation for configuration options and stress testing.

reth snapshots are regularly updated and can be downloaded and extracted with the following commands:

BUCKET="world-chain-snapshots" # use world-chain-testnet-snapshots for sepolia
FILE_NAME="reth_archive.tar.lz4" # reth_full.tar.lz4 is available on mainnet only
OUT_DIR="./" # path to where you would like reth dir to end up
VID="$(aws s3api head-object --bucket "$BUCKET" --key "$FILE_NAME" --region eu-central-2 --query 'VersionId' --output text)"
aws s3api get-object --bucket "$BUCKET" --key "$FILE_NAME" --version-id "$VID" --region eu-central-2 --no-cli-pager /dev/stdout | lz4 -d | tar -C "$OUT_DIR" -x

• Specifications - Detailed technical specifications and architecture
• PBH Overview - Priority Blockspace for Humans concept
• PBH Transaction Lifecycle - Complete walkthrough of PBH transactions
• Validation Rules - Transaction validation requirements

world-chain/
├── crates/
│   ├── world/           # Core World Chain node implementation
│   ├── flashblocks/     # Components for flashblocks construction, propagation, and execution
│   └── toolkit/         # CLI utilities
├── contracts/           # Solidity smart contracts (Foundry)
├── specs/               # Technical specifications (mdBook)
├── docs/                # Additional documentation
├── devnet/              # Local development environment (Kurtosis)
└── snapshotter/         # Database snapshot script

Contributions are welcome! Please see our contributing guidelines and code of conduct.

This project is licensed under the MIT License - see the LICENSE file for details.

• World Chain Explorer
• World ID Documentation
• OP Stack
• Reth