Toss Partners With Optimism and Sunnyside Labs for Korean‑Won Stablecoin POC - Crypto Economy

TL;DR

• Toss Partnership: Toss teams with Optimism and Sunnyside Labs to test a Korean won stablecoin for institutional payments.
• Stablecoin Infrastructure: The three-month PoC evaluates settlement control, compliance requirements, and privacy using Optimism’s OP Stack and Sunnyside’s Privacy Boost.
• Industry Momentum: The company joins a growing list of financial institutions exploring stablecoins, including Shinhan Card, Visa, Mastercard, and BC Card.

Toss is moving deeper into blockchain-based payments through a new partnership with Optimism and Sunnyside Labs aimed at testing a Korean won-backed stablecoin for institutional use. Viva Republica, the operator behind the mobile money transfer platform, signed a memorandum of understanding to launch a three-month proof of concept that evaluates how a compliant, privacy-preserving stablecoin system could fit into South Korea’s financial infrastructure.

Stablecoin POC Anchored by Optimism and Sunnyside Labs

The PoC centers on whether a Korean won-based stablecoin can operate within domestic settlement systems while meeting strict KYC and AML requirements. Toss will rely on Optimism’s OP Stack to supply the blockchain foundation, while Sunnyside Labs contributes its Privacy Boost protocol to keep transactions shielded on a public ledger. According to the report, the three companies will test how financial institutions might control settlement flows, maintain compliance, and preserve privacy without compromising transparency. Toss views this PoC as a stepping stone toward building stablecoin-enabled payment rails that meet regulatory expectations in South Korea.


Toss Expands Its Blockchain Ambitions

Toss, headquartered in Seoul and launched in 2015, claims more than 30 million users on its mobile app. The company’s decision to explore stablecoin infrastructure follows a wave of similar initiatives across the country. In late April, Shinhan Card partnered with the Solana Foundation to test stablecoin payments and non-custodial wallets after completing a pilot project. Shinhan Card also expressed interest in developing DeFi-linked services using blockchain oracles to bridge off-chain and onchain data. Toss is positioning itself within this broader movement by experimenting with stablecoin technology that could eventually support institutional settlement.

Global Players Push Stablecoin Settlement Forward

The momentum extends beyond South Korea. Visa recently rolled out USDC settlement services for select US-based institutions using the Solana blockchain, marking one of the more advanced examples of stablecoin adoption. Mastercard and BC Card are also exploring stablecoin-based payment improvements. For Toss, the collaboration with Optimism and Sunnyside Labs signals a strategic effort to align with global trends while building domestic infrastructure tailored to Korean won settlement needs. As the PoC unfolds, Toss will appear repeatedly in discussions about how stablecoins may reshape institutional payments.