Settlora

Accepting stablecoins should be cheaper and faster than cards for global e-commerce and B2B, but most gateways hold customer funds, which creates custody risk and regulatory burden, and their accounting rarely matches what actually happened on-chain. Price volatility, chain reorganisations and floating-point rounding make it worse.

Settlora set out to let merchants price in USD or INR, get paid in USDC directly to their own wallet with no intermediary account, run staged B2B payments through escrow, and still have books that a finance team can audit to the last minor unit.

Two Solidity 0.8.24 contracts built on OpenZeppelin v5 sit at the core. PaymentRouter atomically splits each payment into the merchant's net settlement and a basis-point platform fee and never retains a balance. MilestoneEscrow supports staged releases, arbiter dispute splits in basis points and mutual EIP-712 cancellations. Foundry runs 29 tests with 100% line coverage, 256 fuzz runs and 8,192 invariant calls, and Slither reports no high or medium issues.

The ledger package implements a full chart of accounts across assets, liabilities, equity, revenue and expenses. Every amount is an integer in minor units (bigint in TypeScript, NUMERIC(38,0) in PostgreSQL), journal entries are append-only, and debits must equal credits at every transaction boundary. Worker services built on Viem crawl blocks for router and escrow events with a persistent cursor, wait for confirmation depth, roll back tentative state if a reorg is detected, then post to the ledger and send HMAC-SHA256 signed webhooks with exponential retries.

A NestJS 10 API with Prisma and OpenAPI documentation serves a Next.js 16 portal. Hosted checkout locks a quote for 30 minutes and supports wallet payments with EIP-2612 permits, EIP-681 QR codes, network selection and ERC-4337 paymaster sponsorship. Merchants get sales KPIs, an invoice generator, a payments explorer and a live journal stream; the escrow manager builds agreements and triggers releases; and the admin engine runs daily ledger-to-chain reconciliation, KYB approvals, OFAC sanctions screening and an emergency freeze.