Monerium, Frax and Capa Connect Euro Payments to Onchain FX Markets on Polygon

Moving money across borders often means changing currencies. Onchain FX lets apps build that exchange directly into the transfer.

The EURe/frxUSD pool on Polygon gives Monerium’s regulated euro token a direct route into dollar liquidity. Users can exchange the two assets, and financial apps can build that exchange into payments and treasury services. It’s now live on Uniswap v3.

For those apps, currency conversion can happen on the same network as the transfer. That creates a foundation for services such as converting customer balances or managing euro and dollar holdings, with payment providers connecting the onchain exchange to bank accounts.

How the euro-dollar swap works

Monerium’s EURe represents euros onchain. It is a MiCA-compliant e-money token, backed 1:1 by safeguarded euro reserves and redeemable at par. Frax’s frxUSD represents the dollar side: a fully collateralized stablecoin backed 1:1 by cash-equivalent reserves, including tokenized U.S. Treasury funds. Capa, a provider of stablecoin FX and cross-border payment infrastructure, joins the integration to help support liquidity and generate real payment flows and FX activity.

How it works: an eligible Monerium customer sends euros through SEPA to their named EUR IBAN. Monerium issues EURe into the linked wallet, and the customer can exchange it for frxUSD through the pool. Uniswap v3 provides the exchange infrastructure, while Polygon settles the swap.

Why Polygon? Polygon’s low network fees make smaller, frequent currency exchanges more practical, while fast finality lets apps confirm a completed trade in seconds. Together, these features help payment and treasury apps use FX as part of everyday money movement. Bank transfers remain separate steps with their own processing times.

What payment apps can build

Onchain FX markets let apps offer currency exchange alongside the balances customers already hold, opening up more ways to save, spend and manage money across currencies.

A wallet could let customers convert part of their euro balance into dollar tokens or a treasury app could use the market to adjust its euro and dollar holdings. Monerium’s API handles onboarding, issuance, redemption and euro payments, so developers can build these features around an existing euro banking connection.

With frxUSD serving as the dollar pairing in other FX pools on Polygon, it gives builders a starting point for routes into additional currencies.