What a stablecoin actually is
Where most cryptocurrencies have a freely floating price, a stablecoin is engineered to stay pinned to a reference value, so the holder can keep money on-chain without the price swings that come with assets like BTC or ETH.
The most common design is a fiat-collateralized stablecoin: the issuer holds reserves intended to back the tokens in circulation and aims to keep the token trading one-to-one with the reference currency. The two you will see most often at checkout are USDT (Tether) and USDC, both pegged to the US dollar. The peg is a design target maintained by the issuer and the market, not a guarantee — in practice the live rate sits very close to one dollar and moves only in small amounts.
Because a stablecoin lives on a blockchain, it is issued on specific networks and inherits each one's speed and fee characteristics. The same dollar of USDT or USDC can travel over different chains, and the network it rides determines how quickly it confirms.
Why stablecoins matter for crypto payments
Volatility is the single biggest obstacle to using crypto as a means of payment. If the asset swings between the moment a customer is quoted and the moment the payment clears, both sides are exposed to a movement that has nothing to do with the sale. Stablecoins remove that exposure: a dollar-pegged token is, for the purposes of a transaction, dollars on a public network. It is why most customers who want to pay in crypto reach for a stablecoin rather than a volatile coin.
For a merchant, a stablecoin is a settlement asset, not a position you take a view on: you are paid in something that tracks the currency you already keep your books in, with the reach and speed of a blockchain.
Stablecoins on halfin
halfin accepts two stablecoins — USDT (Tether) and USDC — across the networks where each has the liquidity that matters for payments. USDT is supported on Tron (TRC-20), Ethereum (ERC-20) and Solana; USDC is supported on Ethereum (ERC-20), Solana and Base. A customer pays whichever stablecoin they hold on whichever of those networks suits them, and every one credits to the same balance.
Crucially, halfin invoices are fiat-anchored: you bill a fiat amount in a fiat currency, and halfin maps that figure to the payable stablecoin amount using the live rate and locks it when the invoice activates. The figure that lands in your ledger is the amount you billed, even though the token's rate only tracks the dollar rather than equalling it exactly. Crediting is reorg-aware and waits for each chain's confirmation threshold before the invoice is marked paid.
From there, stablecoin balances flow through the platform like any asset: convert between assets through balance conversion, pay out through single or mass payouts, or return money to a customer through refunds.
- Pegged to fiat — USDT and USDC both track the US dollar, so neither side absorbs a price swing between quote and payment.
- Multi-network — USDT on Tron / Ethereum / Solana; USDC on Ethereum / Solana / Base; the customer picks the rail.
- Fiat-anchored — bill in fiat, the customer pays the equivalent stablecoin amount, your ledger records the fiat figure.
- Reorg-aware crediting — each chain's confirmation threshold is respected before an invoice is marked paid.