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Swap tokens on xExchange

In this section, you will learn how to swap a token with another on MultiversX. For this, we will use the Devnet xExchange, a MultiversX Decentralized Exchange.

Keep in mind that Devnet and Testnet chains are different! First go to Devnet Wallet and use Faucet functionality to get xEGLD.

DEX

Use Connect button and connect with your wallet via your preferred method.

Let's perform a swap from EGLD to ASH.

SwapASH Notice that for 1 EGLD, we would get 212 ASH tokens.

Let's try to swap more: SwapASH

Notice that for 10 EGLD, we would get 1498 ASH tokens. That's 149.8 ASH tokens for 1 EGLD.

Any intuition of why the drop of exchange rate?

Let's try to swap more: SwapASH

Notice that for 100 EGLD, we would get 3798 ASH tokens. That's 37.98 ASH tokens for 1 EGLD.

Automated Market Maker (AMM)​

An AMM relies on a mathematical formula to price assets. Instead of using an order book like a traditional exchange, assets are priced according to a pricing algorithm.

This formula can vary with each protocol. For example, xExchange DEX uses the industry standard "x*y=k" constant product AMM model, which has proven its reliability in existing implementations, and has been formally modelled and verified. In this formula, k is a fixed constant, meaning the pool’s total liquidity always has to remain the same.

AMM

Pair Smart Contract​

The smart contract code can be found here.

Let's inspect the deployed contract.

AshLPExplorer

Notice the contract's balance:

  • WEGLD: 27.14
  • ASH: 4,817.99
  • ASHWEGLD: 0.000000000000001 - This is the token provided to liquidity providers when they add liquidity. Let's ignore this for now.

Let's try to exchange more ASH than the contract can provide:

SwapASH

In this example, we tried to exchange 100 millions EGLD, but the contract would output 4,580.0391 ASH tokens. That's because of the curve of x*y=k formula (see image above).

Task​

Perform a swap. Go to the Explorer and inspect your transaction. Inspect if there are any evets emitted.