Building Ergo: How the AgeUSD stablecoin works

Guy Brandon

February 5, 2021

The elegant design avoids some of the complexity and potential problems of other approaches to creating decentralised, collateralised stablecoins.

As part of an ongoing joint initiative, Ergo and Cardano unveiled the design of a new stablecoin at the online Ergo Summit event, held on 23 January.

Named AgeUSD and inspired by StatiCoin, the stablecoin is the result of a collaboration between research and development teams across three organisations: IOG (IOHK), the company leading Cardano core development; Ergo Foundation; and blockchain technology company, Emurgo, also one of the founding members of Cardano.

How does it work?

AgeUSD requires just two blockchain assets and two types of users:

  • Reserve Providers, who submit ERG to the AgeUSD dApp’s reserve, thereby minting ReserveCoins
  • AgeUSD Users, who submit ERG to the dApp and receive Stablecoins in return

AgeUSD are only minted for users if there are sufficient reserves in the dApp, deposited by Reserve Providers.

AgeUSD holders can redeem their coins for the equivalent value in ERG at any time. However, ReserveCoins represent a proportion of the reserves held in the dApp (rather than an absolute fiat-equivalent amount). Reserve Providers can only redeem their tokens if the reserves cover the value of all issued stablecoins (multiplied by the minimum reserve ratio).

Thus Reserve Providers take on the responsibility and risk of ensuring that all AgeUSD in circulation are always fully collateralised. In return they receive the potential gains that are secured if the value of the collateral they deposit (ERG) increases. In this respect, becoming a Reserve Provider is like taking a leveraged long position on ERG, and enables regular AgeUSD users to hold and use stablecoins without worrying about volatility. In the event of a market downturn, Reserve Providers do not undergo liquidation and can choose to hold out for better market conditions before redeeming their tokens.

Operation of the AgeUSD dApp is intentionally straightforward, with just four main actions in the allowed:

  • Mint StableCoin
  • Redeem StableCoin
  • Mint ReserveCoin
  • Redeem ReserveCoin

Each action incurs a small fee in ERG – provisionally set at 1% – which is added to the dApp reserve. A further 0.25% is optionally paid to the frontend implementor who creates the interface for minting and redeeming tokens.

‘It’s a simple, elegant design,’ comments Ergo’s founder and lead developer, Alexander Chepurnoy. ‘Its economic model maintains the conservative settings for collateral reserves and avoids the need for liquidations. Along with that, it supports a fully decentralised stablecoin emission setup. Thus, AgeUSD will offer the world a stable, simple, and decentralised stablecoin.'

After launch, scheduled for mid-February, AgeUSD will be available via the Sigmaverse, Ergo’s dApp portal. To find out more, read the documentation at https://github.com/Emurgo/age-usd.

Share post

Bene V2 is Here: Multi-Asset Fundraising, Expanded Wallet Support, and Enhanced UI

Bene V2 is Here: Multi-Asset Fundraising, Expanded Wallet Support, and Enhanced UI

The ecosystem of decentralized applications (dApps) on Ergo is constantly evolving.

Ergo Platform

November 28, 2025

Ecosystem Update: Duckpools Rolls Out V2 Site Preview

Ecosystem Update: Duckpools Rolls Out V2 Site Preview

The team behind Duckpools, a prominent lending and borrowing protocol on the Ergo blockchain, has released a comprehensive develop.

Ergo Platform

November 26, 2025

Ecosystem Spotlight: USE, a Universal Stablecoin for Ergo

Ecosystem Spotlight: USE, a Universal Stablecoin for Ergo

With the protocol nearing deployment, the Community Liquidity Bootstrapping (CLB) event is set to begin on November 25th, allowing.

Ergo Platform

November 24, 2025

Rosen Bridge Nears Bitcoin Runes Launch

Rosen Bridge Nears Bitcoin Runes Launch

Rosen Bridge has entered the final phase for its Bitcoin Runes integration. You can now set up your Bitcoin-Runes watcher.

Ergo Platform

November 23, 2025

GitCircles and Ergo: Fair Rewards for Open Source Contributions

GitCircles and Ergo: Fair Rewards for Open Source Contributions

Open source software powers much of the digital world — from the apps on your phone to the infrastructure of the internet itself.

Ergo Platform

October 12, 2025

Bitcoin Runes + Rosen Bridge: A Practical Path for Multi-Chain Fungible Assets

Bitcoin Runes + Rosen Bridge: A Practical Path for Multi-Chain Fungible Assets

The big idea Bitcoin finally has a clean way to represent fungible tokens.

Ergo Platform

September 30, 2025

ChainCash: Money That Carries Its Own Story

ChainCash: Money That Carries Its Own Story

ChainCash records reserves and signatures for each note on Ergo.

Ergo Platform

September 23, 2025

Braiding Lunarpunk and Solarpunk through Merged Mining

Braiding Lunarpunk and Solarpunk through Merged Mining

The question is simple.

Ergo Platform

September 2, 2025

Machina Finance: Off-Chain Execution, On-Chain Trust

Machina Finance: Off-Chain Execution, On-Chain Trust

Machina Finance is an innovative, bot-driven decentralized exchange (DEX) being developed on the Ergo blockchain.

Ergo Platform

September 1, 2025

Ergo Infrastructure DAO: Decentralizing the Backbone of the Ergo Ecosystem

Ergo Infrastructure DAO: Decentralizing the Backbone of the Ergo Ecosystem

Ergo’s mission has always been rooted in decentralization, not just at the consensus layer, but across the entire stack.

Ergo Platform

August 13, 2025

Mew Finance: A Playful DeFi Toolkit for the Ergo Ecosystem

Mew Finance: A Playful DeFi Toolkit for the Ergo Ecosystem

Mew Finance is a decentralized application suite on the Ergo Blockchain.

Ergo Platform

August 12, 2025

Lithos: Decentralizing Mining with On-Chain Pools

Lithos: Decentralizing Mining with On-Chain Pools

Lithos is a new protocol designed to overhaul how mining pools work by moving them on-chain, giving miners full control, and elimi.

Ergo Platform

July 24, 2025

Sigma 6.0: A Smarter, More Flexible Ergo

Sigma 6.0: A Smarter, More Flexible Ergo

Sigma 6.0 is a major proposed upgrade to the Ergo blockchain.

Ergo Platform

July 23, 2025

Shaping Rosen's Future: A Community Call on Five Key Treasury Proposals

Shaping Rosen's Future: A Community Call on Five Key Treasury Proposals

Rosen co-founder, Armeanio, has submitted five new proposals to the Rosen Treasury.

Ergo Platform

July 9, 2025

Ergo's Extended UTXO and the Rise of Artificial Economic Intelligence

Ergo's Extended UTXO and the Rise of Artificial Economic Intelligence

A Practical Vision for Autonomous Economic Agents Autonomous economic agents on the Ergo blockchain perform useful work in a real.

Ergo Platform

May 12, 2025

ErgoHACK X: Artificial Intelligence on the Ergo Blockchain

ErgoHACK X: Artificial Intelligence on the Ergo Blockchain

Celebrating a Decade of Decentralized Innovation Join the 10th anniversary ErgoHACK and be at the forefront of the AI revolution o.

Ergo Platform

April 10, 2025

Ergohack 9: Innovations in UI/UX and Mining – Meet the Visionary Winners!

Ergohack 9: Innovations in UI/UX and Mining – Meet the Visionary Winners!

The latest annual Ergo hackathon, ErgoHack IX, was a six-day event held at the end of October.

Ergo Platform

December 9, 2024

ErgoHack IX: Next Steps Towards Increased Adoption

ErgoHack IX: Next Steps Towards Increased Adoption

We’ve come a long way since the early days of Bitcoin, and cryptocurrencies have boomed into an industry with thousands and thousa.

Ergo Platform

October 20, 2024

Ergo Vs Other Blockchain Platforms: What’s The Difference?

Ergo Vs Other Blockchain Platforms: What’s The Difference?

Ergo offers a series of unique features that set it apart from other blockchain platforms.

Ergo Platform

August 19, 2024

Earning With The Rosen Bridge

Earning With The Rosen Bridge

Bitcoin has officially bridged to the Ergo ecosystem via Rosen Bridge! This newly built, decentralized infrastructure enables trus.

Ergo Platform

August 8, 2024

How Sigma Chains Will Bring Bitcoin To Ergo

How Sigma Chains Will Bring Bitcoin To Ergo

Ergo’s powerful, flexible, and secure smart contract functionality opens the door to a whole host of new use cases for Bitcoin DeF.

Ergo Platform

July 15, 2024