Rhinestone

Rhinestone provides self-custodial stablecoin infrastructure for fintechs, helping companies launch financial products in weeks rather than spending months assembling separate vendors. Its platform connects wallets, deposits, transaction relaying and fiat integrations through one integration and service-level agreement.

The wallet product uses passkey-based sign-up and client-side key generation, with gas abstraction and multichain functionality. Hosted deposit and withdrawal flows let users fund accounts through wallets, exchanges, cards, Apple Pay or bank transfers, with funds settled as a token on a selected chain. Relaying supports gas sponsorship, cross-chain execution and liquidity routing, while fiat integrations include virtual bank accounts, stablecoin cards and KYC through licensed partners.

Rhinestone’s technology is built on account abstraction. The company says it helped define the modular smart account movement and created ERC-7579, a standard used by smart account wallets. Its infrastructure serves fintechs as well as DeFi protocols, agentic platforms and onchain applications. The site reports $4.8 billion in annualized flow and 5.2 million transactions, and lists security audits by specialist blockchain firms.