This repository provides a comprehensive Solidity implementation of the ERC-734 (Key Holder) and ERC-735 (Claim Holder) standards for decentralized on-chain identities. It includes a core Identity contract that manages cryptographic keys (management, action, claim, encryption) and claims (issuance, storage, revocation), along with a ClaimIssuer contract for issuing and revoking claims. The system supports proxy-based upgradeability via an ImplementationAuthority and IdentityProxy, allowing identity contracts to be upgraded without losing state. A factory contract (IdFactory) enables deterministic deployment of identity proxies using CREATE2, with support for wallet linking and token identity creation. A Gateway contract provides an off-chain authorization layer for identity deployment, managing approved signers and signature revocation. A Verifier contract allows other contracts to verify that an identity holds valid claims from trusted issuers for required topics. The architecture is modular, well-tested, and follows security best practices including signature malleability protection. It is designed for use in decentralized identity (DID) systems on EVM-compatible blockchains.