BIP-0003: Adding ZUSD to the XUSD aggregator

BIP-0003: Adding ZUSD to the XUSD aggregator


Zero is a decentralized stablecoin and borrowing protocol, originating as a fork of Liquity. Users put up collateral to receive a 0% interest loan denominated in stablecoins issued on-demand by the Zero protocol. The stablecoin issued by the Zero protocol is ZUSD, a USD-pegged stablecoin backed by RBTC with a minimum 110% collateralization ratio.


We propose to add ZUSD to the BabelFish XUSD aggregator. This will enable users to deposit ZUSD in exchange for XUSD and then redeem XUSD for the underlying ZUSD.


We believe that adding ZUSD to the XUSD aggregator has its benefits for both BabelFish and Sovryn:

  • Being overcollateralized by BTC, ZUSD can provide a strong, censorship-resistant backing that fiat stablecoins are unable to offer. ZUSD presents a compelling, differentiated source of USD-pegged stability for XUSD.
  • The BabelFish and Sovryn communities have together spent the last year building liquidity and utility for XUSD, including spot and margin trading, borrowing, and lending capabilities. By adding ZUSD to the XUSD aggregator we can give ZUSD holders access to all of these capabilities without having to build them up for ZUSD in parallel. Rather than competing with XUSD for liquidity, ZUSD becomes part of XUSD liquidity.

Further details

For more information about Zero check out the following sources:


  • If this proposal is approved, ZUSD will be added to the XUSD aggregator on RSK mainnet.