Overview
The Starknet World ID Bridge connects World's proof-of-personhood system to the Starknet ecosystem. This integration enables developers to incorporate human verification into their Starknet DApps while preserving user privacy through zero-knowledge proofs.
Developed as part of a targeted grant from the World Foundation, this bridge represents a strategic enhancement to Starknet's capabilities, positioning it among the growing ecosystem of networks supporting World ID verification. The implementation utilizes Garaga's Groth16 verifier written in Cairo, addressing one of the most significant technical challenges in bringing World ID to non-EVM environments.
Current Status & Roadmap
The Starknet World ID Bridge is under active development with substantial progress on core components. The engineering team at Nethermind is focused on delivering a production-ready solution that meets the high standards of both Starknet and World infrastructure.
Development Timeline
The development process is structured into focused phases:
Ready to start building? Check out our Getting Started guide.
Technical Architecture
The bridge employs a secure cross-chain architecture to enable World ID verification on Starknet.
On Ethereum (L1), a dedicated contract monitors the World ID Identity Manager to access the latest identity Merkle tree root. This root hash serves as a cryptographic commitment to the entire set of verified World ID identities.
The root data is transmitted to Starknet (L2) via Starknet's L1-L2 messaging mechanism, which provides secure asynchronous communication between Ethereum and Starknet. This mechanism ensures that only authorized messages from the L1 contract can update the state on L2.
On Starknet, a Cairo implementation receives these roots and implements a specialized Groth16 zero-knowledge proof verifier. This verification system allows Starknet applications to validate World ID proofs without requiring additional L1 interactions, providing gas-efficient and privacy-preserving identity verification.
For end-users, the process is seamless—they generate World ID proofs through the standard World ID interface, then submit these proofs to Starknet applications. The on-chain verification confirms their unique humanity status without revealing biometric data or personal information.
Learn more about the benefits this brings to developers in Why It Matters.
Join the Ecosystem
Developers are invited to explore, test, and contribute to this critical infrastructure project. The source code is available on GitHub, with comprehensive documentation to guide users through understanding and working with the bridge.
By integrating the Starknet World ID Bridge into applications, developers join the growing movement toward more secure, privacy-preserving, and authentically human digital experiences.
Get started with integration by following our Getting Started guide or learn about the Prerequisites needed for development.