Build programmable commerce

Mayarin is a programmable clearing layer for merchants who think in local currency. Your application creates a fiat-denominated payment request; Mayarin handles quoting, on-chain execution, settlement, and accounting.

One payment request, three kinds of payer: a human at a checkout, an application paying on their behalf, or an autonomous agent paying per call over x402 with no account of any kind.

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Here’s a quick guide to help you find what you need:

Reading a finished integration is often faster than any of the above: apps/demo is a complete storefront — thin server, webhook endpoint, and all.

The model

Merchant prices       its own currency (SGD, MYR, THB, USD, IDR…)
Customer pays         ETH, USDC, USDT, or EURC
Mayarin executes      quote → pay → swap if needed → settle
Merchant receives     configured stablecoin

The merchant does not need to reconcile the payer’s asset. The customer does not need to acquire the merchant’s settlement asset first. See rails for the currencies, assets and chains this covers.

Three execution paths

Chosen per payer, not per deployment — none is a fallback for another:

• On-chain contract — the payer connects a wallet. PaymentRouter atomically receives, swaps when needed, and settles. A hard minOut protects the merchant.
• Deposit match — the payer can only send a plain transfer, from a wallet or an exchange. Mayarin gives them a per-intent address, watches the chain, and matches the transfer to the payment.
• x402 — the payer is a program. It signs one authorization for an exact amount, a facilitator broadcasts it, and the settlement is read back off the chain before anything is served.

All three use the same payment intent, status model, ledger, and merchant-facing API. See execution paths.

Core guarantees

• Money is represented as exact minor units, never floating-point values.
• Every write is idempotent.
• Every clearing transition is persisted and auditable.
• A webhook is a signal; Mayarin verifies authoritative state before settlement.
• Secret keys stay on the server. Browser integrations use publishable keys with a deliberately smaller surface.