Paying gas in dollars
On most blockchains you must hold a volatile native coin to pay for a transaction. Tempo removes that step. Fees are paid directly in USD-denominated stablecoins issued under the TIP-20 standard, so a payer who only holds dollars never needs to acquire a separate gas token.
Because there is no native coin, the VM reflects this directly: BALANCE and SELFBALANCE return 0. Base fees for a simple transfer target under $0.001, making per-transaction cost predictable in dollar terms rather than fluctuating with a token price.
The Fee AMM
Many different stablecoins can circulate on Tempo, and a validator may prefer to be paid in a specific one. The Fee AMM is a protocol-native automated market maker used only to convert transaction fees between stablecoins.
When a payer's fee token differs from a validator's preferred token, the Fee AMM converts it automatically at a fixed rate. Liquidity providers to the Fee AMM earn 0.3% per swap. Importantly, the Fee AMM is a separate system from the general-purpose Stablecoin DEX — it exists purely to settle fees, not to trade.
The Fee Manager
Fee-token selection and conversion are coordinated by the Fee Manager, a Tempo system contract (at 0xfeec…). It works together with the Fee AMM so that users can pay gas in any qualifying USD-denominated TIP-20 while validators still receive their preferred stablecoin.
Where no single stablecoin is the natural intermediary, an optional neutral quote token, pathUSD (at 0x20c0…), can provide conversion paths for the Fee AMM.