Fee AMM Overview
The Fee AMM (Automated Market Maker) is a dedicated system for converting transaction fees between different stablecoins. It enables users to pay fees in any supported stablecoin while allowing validators to receive fees in their preferred token.
How the Fee AMM converts stablecoin fees
When a user pays fees in a stablecoin that differs from the validator's preference, the Fee AMM automatically converts the payment:
- User pays: 1.0 of their chosen stablecoin
- Validator receives: 0.9970 of their preferred stablecoin
- Liquidity providers earn: 0.003 (0.3%) as fees
This conversion happens automatically at the end of each block through batched swaps, preventing MEV attacks like sandwiching.
Fee AMM vs. Exchange
Tempo has two stablecoin-swapping systems that are easy to confuse. They serve different purposes:
| Exchange (DEX) | Fee AMM | |
|---|---|---|
| Purpose | User-facing stablecoin trading | Converting transaction fees into validators' preferred tokens |
| Who initiates swaps | Users and apps | The protocol, automatically (plus arbitrageurs rebalancing) |
| Pricing | Market-driven orderbook (price-time priority) | Fixed conversion price |
| Liquidity | Limit and flip orders resting in the orderbook | LP deposits into per-pair fee pools |
| Contract | Stablecoin DEX precompile (0xdec0…0000) | FeeManager precompile (0xfeec…0000) |
| Use it for | Swaps, prices, orderbook depth, fills | Letting users pay fees in any stablecoin |
If you want to trade stablecoins or read market data, use the Exchange. If you want to enable fee payments in your stablecoin or provide fee-conversion liquidity, you're in the right place — continue below.
Learn more about fee conversion
Enable users to pay fees using your stablecoin
Complete Fee AMM protocol specification
Provide liquidity to enable fee token conversions
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