OPNfi

What we built

OPNfi is a yield-tokenization and fixed-rate money market for OPN Chain. It wraps any yield-bearing asset into a Standardized Yield token (SY), then splits it into two tradable ERC-20s:

• PT (Principal Token) — redeems 1:1 for principal at maturity. Buying PT below par locks a fixed rate.
• YT (Yield Token) — captures all variable yield until maturity. Pure yield exposure.

A purpose-built PT/SY AMM (PtAmmV2) gives them price discovery and liquidity, and a Router bundles multi-step actions into one transaction.

tUSD → SYToken → YieldTokenization → PT + YT
                          ↓
                  PtAmmV2 (PT/SY AMM)
                          ↓
                       Router (1-tx flows)

Why it matters

A new chain needs a base interest-rate market. OPNfi provides it permissionlessly:

• Fixed-rate lending/borrowing — lock a known return by buying PT.
• Yield speculation & hedging — trade the yield stream in isolation via YT.
• LP-friendly liquidity — the AMM curve flattens toward maturity, cutting impermanent loss.
• Composability — PT, YT and SY are plain ERC-20s any protocol can build on.

It is a financial primitive others build on, while also shipping a yield product, a liquidity venue, and an AMM in one stack.

How it works

• Split: deposit tUSD → SY → split into equal PT + YT in one tx via Router.depositAndSplit.
• Trade: buy/sell PT on PtAmmV2, a StableSwap curve whose amplification grows over time — far from maturity = more curvature, near maturity = ~1:1 pricing as PT converges to par.
• Provide liquidity: add PT + SY, earn swap fees, withdraw anytime.
• Redeem at maturity: PT → principal, YT → accrued yield. PT + YT always reconstructs the original position.

Status

• 8 Solidity contracts (0.8.30, OpenZeppelin v5), 29/29 tests passing
• Deployed and source-verified on OPN Testnet (chainId 984)
• Full Next.js + wagmi dApp: dashboard, split, trade, liquidity, faucet
• Live demo: https://opnfi.vercel.app · Code: https://github.com/luonglee1/opnfi