How We Built Treasury Yield Infrastructure on Circle’s Arc Blockchain

Most builders hear "new Layer-1" and scroll past. Fair enough. The market doesn't need another chain. But when Circle unveiled Arc's public testnet in October 2025, we stopped scrolling. This wasn't another blockchain fishing for liquidity incentives. This was the company behind USDC, behind CCTP, behind a $75 billion stablecoin empire, saying: we're building the chain that money deserves.

We're AbdelAziz and Fayssal, brothers and co-founders of Meridian Finance. We shipped our first smart contract on Arc the same day the testnet went live. We haven't stopped since.

The numbers as of February 2026: 28 deployed smart contracts. 3,000+ unique wallets. $160K+ total value locked. 5,000+ on-chain transactions. Marketing budget: zero. Every wallet found us organically.

This is our story. The wins, the disasters, and why we'd bet on Arc all over again.

Before we talk about what we built, let's talk about who we're building with. Because the infrastructure underneath your protocol matters more than the code on top.

USDC ended 2025 at $75 billion market cap. That's a 73% jump year-over-year, and it outpaced Tether's growth for the second straight year. Over $50 trillion in cumulative on-chain volume has moved through USDC since launch. BlackRock manages the reserve. BNY provides custody. Deloitte handles attestations.

EURC, the euro stablecoin, surged from 70M to 300M+ euros in 2025. USYC, Circle's Treasury yield token backed by US T-bills, hit $1.54 billion in AUM.

Circle is publicly traded on the NYSE under CRCL. The GENIUS Act gave stablecoins a legal framework in the US. The OCC gave Circle conditional approval to establish a national trust bank.

When you build DeFi yield infrastructure on USDC, you want to be on the chain that was purpose-built for USDC. That's Arc.

We've shipped code on Ethereum, Base, Arbitrum, Sepolia. Arc is EVM-compatible so the tooling is familiar. Foundry, Hardhat, Solidity, everything works. But three things set it apart.

Dollar-denominated gas. Every other chain forces your users to acquire a volatile token before they can do anything. Buy ETH. Buy MATIC. Swap something somewhere. On Arc, gas is paid in USDC. A stablecoin. Predictable fees. No volatility surprises. This removes the single biggest barrier for non-crypto-native users.

Deterministic sub-second finality. Not probabilistic. Not "wait for 12 confirmations." Deterministic. Your transaction is done in under 500 milliseconds. We've verified this across thousands of vault deposits. For payment applications, this is transformational.

The institutional roster. Arc's testnet participants include BlackRock, Deutsche Bank, HSBC, Goldman Sachs, Visa, Mastercard, Coinbase, Robinhood, Societe Generale. Developer tools from Alchemy, Chainlink, Thirdweb. DeFi protocols like Aave, Curve, Uniswap, Morpho. No chain in history has launched with this caliber of institutional backing on day one.

We built two products. Both live, both functional, both generating real yield on testnet.

Treasury Yield Vaults. Deposit USDC or EURC. Our contracts convert it to USYC through Hashnote's Teller, which represents tokenized US Treasury bills. Your deposit earns roughly 3.2% APY, backed by the safest asset in traditional finance. Withdraw anytime and receive your original deposit plus accumulated yield, all in USDC.

Use cases: stablecoin savings, idle capital management, and more.

The protocol charges zero deposit fees. Minimal withdrawal fees and a performance fee on yield generated, not on principal. Every fee is collected automatically by the smart contracts and sent to our Treasury wallet. No manual intervention, no trust assumptions.

Real-Time Payment Streaming. Instead of lump-sum transfers, money flows continuously by the second. An employer deposits USDC into a stream, and the recipient’s balance increases in real time. Every second, more appears. The deposited funds sit in USYC during the stream duration, generating Treasury yield while being distributed.

Use cases: payroll streaming, token vesting and more.

Both products support USDC and EURC. Both generate PDF and CSV reports with legal disclaimers, on-chain verification links, and full transaction history. Enterprise-grade accounting, even on testnet.

Tools don't get enough credit in crypto. Everyone talks about tokenomics and narrative. Nobody talks about the infrastructure that actually makes things work. Here's what Circle gives you, and why it matters.

CCTP (Cross-Chain Transfer Protocol). Traditional bridges lock your tokens on one side and mint synthetics on the other. If the bridge gets hacked, your wrapped tokens go to zero. In 2022, bridge exploits cost the industry over $2 billion. CCTP eliminates this entirely. It burns USDC on the source chain and mints fresh native USDC on the destination. No wrapping. No bridge risk. Circle authorizes every single mint. We integrated CCTP so users can deposit into Meridian's vault from Ethereum, Base, Arbitrum, and Polygon, all arriving as real USDC on Arc.

Gateway. CCTP is secure but the attestation process adds a few minutes of wait. Gateway goes further. One deposit into a unified balance, then instant access on any supported chain in under 500ms. No pre-funding each chain separately. For treasury management at scale, this is a game changer. We're integrating Gateway as our primary cross-chain route, with CCTP as the reliable fallback.

Modular Smart Contract Accounts with Passkey Authentication. The standard crypto onboarding asks users to write down 24 random words, install a browser extension, and buy volatile tokens for gas. Circle's MSCA stack removes all of that. Our users sign up with a username and authenticate with Face ID or fingerprint. The private key lives in the device's Secure Enclave, never exposed, never written down. The same address works across 8 chains. Circle's Paymaster covers gas fees so users never need to hold anything other than stablecoins.

The Teller. Hashnote's integration with Circle that converts USDC into USYC, a tokenized claim on US Treasury bills. This is what powers our vault's yield. Users deposit dollars, get exposure to government debt, and withdraw with yield. Fully on-chain. Fully transparent.

Each tool solves a specific, painful problem. CCTP kills bridge risk. Gateway kills cross-chain friction. MSCA kills seed phrases. Paymaster kills gas confusion. Teller connects DeFi to real-world yield. Together, they form the most complete developer stack in crypto. And they all work natively on Arc. Circle doesn't just give you a chain. They give you everything you need to build serious financial applications.

Here's the truth about building in production. It's mostly debugging at 3am wondering why everything is broken.

The slash that cost us three days. Our smart accounts refused to deploy. The error: "method does not exist." We checked configurations, API keys, dependency versions. Everything looked correct. The culprit? A missing forward slash in the transport URL. The chain path wasn't appended to the bundler endpoint. Three days of debugging. One character.

The git checkout that erased a full night of work. This one still hurts. I'd been coding until 4am. Animations, new logo, UI polish, the frontend was finally looking right. Went to sleep. Next day, I wanted to undo one small change and ran git checkout without thinking. It reverted everything. Not just the small change. Everything. The animations, the logo, the hours of UI work, all gone. I hadn't committed. There's no undo button for that. I closed the terminal, took a breath, made some coffee, and rebuilt the entire thing from scratch. When you're building something you believe in, you don't quit over a bad terminal command. You just start again.

Silent UserOperation failures. No error message. No revert reason. Just nothing. You submit a transaction and the blockchain acknowledges it exists but refuses to tell you why it didn't execute. This is especially fun at 2am when you're trying to debug a passkey wallet deposit flow.

The whitelisting wait. Arc requires smart contract whitelisting. Every day waiting for approval is a day you can't test under real conditions. The patience required is real, but the Circle team, especially Tim B. from Developer Relations, went above and beyond to support us through the process. Builders helping builders. That's not marketing speak, it's what we experienced firsthand.

The rebrand nobody expected. Our original company name had trademark considerations. What felt like a crisis at the time became the best pivot we ever made. Meridian Finance. A meridian is a line connecting two points on a globe. That's our entire thesis: connecting the Treasury yields of Wall Street to anyone with a wallet and an internet connection, anywhere in the world.

Building on testnet sounds safe. It's not. When your protocol handles real yield mechanics and cross-chain transfers, every edge case is a production bug waiting to happen. But Circle's stack makes the hard parts manageable. The documentation is thorough, the SDKs work, and when something breaks, the developer community on Discord actually helps you fix it.

We get this question constantly. Here's our honest answer.

Alignment. Arc is built by Circle. USDC is built by Circle. USYC is built by Circle. CCTP, Gateway, Paymaster, all Circle. When your entire protocol runs on USDC and USYC, being on the chain designed specifically for those assets means native integration instead of bolted-on patches.

The stablecoin thesis. The market grew 42% in 2025 to nearly $300 billion. JPMorgan reported that USDC captured 25.5% market share, up 400 basis points, while Tether's dominance declined. 84% of financial firms are using or exploring stablecoins for enterprise operations. This isn't speculation anymore. It's infrastructure becoming the standard.

Regulation as a competitive moat. Other chains attract developers with token incentives. Arc attracts institutions through compliance. Opt-in privacy. Deterministic settlement that meets international settlement standards. Dollar-denominated fees for clean accounting. When Goldman Sachs and HSBC are testing your chain, that's not a marketing bullet point. That's a signal about where serious capital flows next.

The agentic economy. Autonomous software agents will need financial infrastructure. Agents that hold balances, execute payments, optimize yield. We built YieldClaw, an autonomous agent that manages yield strategies on our vault, for the OpenClaw hackathon. This isn't science fiction. It's happening right now.

Arc mainnet launches in 2026… We're getting ready.

Near-term: full Gateway integration for instant cross-chain deposits. StableFX integration for native USDC/EURC swaps. Multi-currency payment streaming where an employer deposits one currency and the recipient receives another. Auto-compounding yield. Lock periods with bonus APY.

Medium-term: liquidity pools for cross-currency swaps with shared yield. Tokenized real-world asset integration as Arc expands support. Professional security audit from a top-tier firm before mainnet.

Long-term: enterprise treasury management. Companies depositing idle cash into yield vaults instead of bank accounts earning nothing. Streaming payroll by the second. Autonomous yield agents per enterprise with compliance reporting. A full B2B platform where businesses subscribe for vault access, payment streaming, and automated capital management.

The internet needs an economic operating system. Not another blockchain that treats money as an afterthought, but infrastructure where money is the primary design consideration. Where transactions settle in milliseconds, cost fractions of a cent, and are denominated in dollars.

Circle is building that foundation with Arc. We're building on top of it.

Try Meridian Finance: themeridian.finance

Build on Arc: arc.network

The future of money is programmable. And it's already running.

AbdelAziz and Fayssal are co-founders of Meridian Finance. First to deploy smart contracts using USYC on Arc testnet. First whitelisted DeFi protocol on the network.

Follow the project on X: @Meridian_Fi