Toss, Optimism to Pilot Korean-Won Stablecoin PoC

Toss, the Seoul-based operator of the Toss mobile app, and Optimism signed a memorandum of understanding to run a three-month proof of concept to develop a Korean won–pegged stablecoin for institutional payments in South Korea.

Under the agreement, Toss’s parent Viva Republica will work with Optimism and privacy solutions provider Sunnyside Labs. Optimism will provide Layer 2 infrastructure using its OP Stack while Sunnyside will supply Privacy Boost, a protocol designed to shield transfer details on a public ledger. The pilot will focus on technical and compliance questions relevant to banks and payment firms.

The proof of concept will test whether financial institutions can retain control of the settlement process when using an onchain stablecoin and whether standard checks such as know-your-customer and anti-money-laundering procedures can be carried out alongside privacy protections.

Participants will assess whether transaction privacy can be maintained on a public chain while meeting regulatory reporting and institutional audit requirements. Toss intends to use the pilot findings as the basis for building compliant stablecoin payment infrastructure in South Korea.

Sunnyside Labs is a core developer for the Optimism Collective and has contributed to components of the OP Stack. Optimism’s OP Stack is an open-source framework for building Layer 2 networks that increase transaction throughput and reduce costs compared with mainnet settlement.

Toss was founded in 2015 and its app has more than 30 million users in South Korea. The company expanded from peer-to-peer transfers into broader financial services.

The pilot follows other experiments with stablecoins for payments and settlement. A major South Korean card issuer has trialed stablecoin payments and non-custodial wallets, and global payment firms including Visa, Mastercard and BC Card have run stablecoin settlement pilots.

Results from the three-month proof of concept are expected to inform whether a Korean won–pegged stablecoin can be structured to meet the operational needs of payment providers and local compliance requirements.