Redeem FAssets

Overview

In this guide, you will learn how to redeem FAssets using the Asset Manager smart contract.

Redemption is the process of burning FAssets (e.g., FXRP) on Flare in exchange for their equivalent value on the original chain (e.g., XRP on XRPL).

See the Redemption overview for more details.

Prerequisites

Redeem FAssets Smart Contract

The following example demonstrates how to redeem FAssets using the AssetManager smart contract.

contracts/FAssetsRedeem.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.25;

import {ContractRegistry} from "flare-periphery-contracts-fassets-test/coston2/ContractRegistry.sol";
import {IAssetManager} from "flare-periphery-contracts-fassets-test/coston2/IAssetManager.sol";
import {AssetManagerSettings} from "flare-periphery-contracts-fassets-test/coston2/data/AssetManagerSettings.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {RedemptionRequestInfo} from "flare-periphery-contracts-fassets-test/coston2/data/RedemptionRequestInfo.sol";

contract FAssetsRedeem {
    // 1. Redeem FAssets
    function redeem(
        uint256 _lots,
        string memory _redeemerUnderlyingAddressString
    ) public returns (uint256) {
        // Calculate the amount of FXRP needed for redemption
        IAssetManager assetManager = ContractRegistry.getAssetManagerFXRP();
        AssetManagerSettings.Data memory settings = assetManager.getSettings();
        uint256 amountToRedeem = settings.lotSizeAMG * _lots;

        IERC20 fAssetToken = IERC20(getFXRPAddress());
        // Transfer FXRP from caller to AssetManager
        fAssetToken.transferFrom(msg.sender, address(this), amountToRedeem);

        uint256 redeemedAmountUBA = assetManager.redeem(
            _lots,
            _redeemerUnderlyingAddressString,
            payable(address(0))
        );

        return redeemedAmountUBA;
    }

    function getFXRPAddress() public view returns (address) {
        IAssetManager assetManager = ContractRegistry.getAssetManagerFXRP();
        return address(assetManager.fAsset());
    }

    // 2. Get the AssetManager settings
    function getSettings()
        public
        view
        returns (uint256 lotSizeAMG, uint256 assetDecimals)
    {
        IAssetManager assetManager = ContractRegistry.getAssetManagerFXRP();
        AssetManagerSettings.Data memory settings = assetManager.getSettings();
        lotSizeAMG = settings.lotSizeAMG;
        assetDecimals = settings.assetDecimals;

        return (lotSizeAMG, assetDecimals);
    }

    // 3. Get the redemption request info
    function getRedemptionRequestInfo(
        uint256 _redemptionTicketId
    ) public view returns (RedemptionRequestInfo.Data memory) {
        IAssetManager assetManager = ContractRegistry.getAssetManagerFXRP();

        return assetManager.redemptionRequestInfo(_redemptionTicketId);
    }
}

Open in Remix

Code Breakdown

Redeem the FAssets using the redeem function by specifying the number of lots to redeem and the underlying chain address.
Retrieve the asset manager settings to calculate the redeemed amount; for this, you need to obtain the lotSizeAMG and assetDecimals from the asset manager settings document.
Get the redemption request info to check the redemption status.

info

In this example, you are not using the executor vault address, but you can use it to redeem FAssets on behalf of another address.

Deploy and Interact with the Smart Contract

To deploy the contract and redeem FAssets, you can use the Flare Hardhat Starter Kit.

Create a new file, for example, scripts/fassets/redeem.ts and add the following code:

Import the Required Contracts

At first, you need to import the required dependencies and smart contract TypeScript types:

import { web3, run } from "hardhat";
import { formatUnits } from "ethers";

import { FAssetsRedeemInstance, ERC20Instance } from "../../typechain-types";

import { logEvents } from "../../scripts/utils/core";

Define the Constants

Define the constants:

LOTS_TO_REDEEM - the number of lots to redeem;
UNDERLYING_ADDRESS - underlying chain address where the redeemed asset will be sent;

const LOTS_TO_REDEEM = 1;
const UNDERLYING_ADDRESS = "rSHYuiEvsYsKR8uUHhBTuGP5zjRcGt4nm";

Import Contract Artifacts

Import the contract artifacts to interact with the smart contracts:

FAssetsRedeem - the FAssetsRedeem contract;
IAssetManager - the asset manager interface;
IERC20 - the IERC20 contract for FXRP token;

const FAssetsRedeem = artifacts.require("FAssetsRedeem");
const AssetManager = artifacts.require("IAssetManager");

const IERC20 = artifacts.require("IERC20");

Deploy and Verify the Redeem Contract

Deploy and verify the smart contract providing the asset manager address as a constructor argument:

async function deployAndVerifyContract() {
  const fAssetsRedeem: FAssetsRedeemInstance = await FAssetsRedeem.new();

  const fAssetsRedeemAddress = fAssetsRedeem.address;

  try {
    await run("verify:verify", {
      address: fAssetsRedeemAddress,
      constructorArguments: [],
    });
  } catch (e: any) {
    console.log(e);
  }

  console.log("FAssetsRedeem deployed to:", fAssetsRedeemAddress);

  return fAssetsRedeem;
}

Approve the FXRP transfer to the Redeem Contract

To redeem FAssets, you must approve a sufficient amount of transfer of FXRP to the FAssetsRedeem contract address after it is deployed, as it acts as the invoker during the redemption process.

async function approveFAssets(fAssetsRedeem: any, amountToRedeem: string) {
  console.log("Approving FAssetsRedeem contract to spend FXRP...");
  const fxrpAddress = await fAssetsRedeem.getFXRPAddress();
  const fxrp: ERC20Instance = await IERC20.at(fxrpAddress);

  const approveTx = await fxrp.approve(
    await fAssetsRedeem.address,
    amountToRedeem,
  );
  console.log("FXRP approval completed");
}

warning

In a production environment, it is recommended to use a more secure method for approving the transfer of FXRP to a smart contract.

Parse the Redemption Events

During the redemption process, the AssetManager emits events:

RedemptionRequested - holds the agent vault address, redemption request id, the amount of FAssets to redeem, and other important information.
RedemptionTicketCreated - holds the redemption ticket information updated during the redemption process.
RedemptionTicketUpdated - holds the redemption ticket information updated during the redemption process.

To parse the redemption events, you can use the following function:

async function parseRedemptionEvents(
  transactionReceipt: any,
  fAssetsRedeem: any,
) {
  console.log("\nParsing events...", transactionReceipt.rawLogs);

  const redemptionRequestedEvents = logEvents(
    transactionReceipt.rawLogs,
    "RedemptionRequested",
    AssetManager.abi,
  );
  logEvents(
    transactionReceipt.rawLogs,
    "RedemptionTicketCreated",
    AssetManager.abi,
  );
  logEvents(
    transactionReceipt.rawLogs,
    "RedemptionTicketUpdated",
    AssetManager.abi,
  );

  return redemptionRequestedEvents;
}

info

The logEvents function is used to parse and log the events interacting using the Truffle suite of tools. You can find this function in the Flare Hardhat Starter Kit. In this guide, we are not focusing on the event parsing.

Output the Redemption Result

The following function is used to output the redemption request information.

async function printRedemptionRequestInfo(
  fAssetsRedeem: any,
  redemptionRequestedEvents: any[],
) {
  console.log("\n=== Redemption Request Information ===");

  for (const event of redemptionRequestedEvents) {
    const redemptionRequestInfo = await fAssetsRedeem.getRedemptionRequestInfo(
      event.decoded.requestId,
    );
    console.log("Redemption request info:", redemptionRequestInfo);
  }
}

Redeeming FAssets

To put it altogether you can use the following function to deploy the contract, transfer FXRP to it, redeem the FAssets, and parse the redemption events:

async function main() {
  // Deploy and verify the contract
  const fAssetsRedeem = await deployAndVerifyContract();

  // Get the lot size and decimals to calculate the amount to redeem
  const settings = await fAssetsRedeem.getSettings();
  const lotSize = settings[0];
  const decimals = settings[1];
  console.log("Lot size:", lotSize.toString());
  console.log("Asset decimals:", decimals.toString());

  // Calculate the amount to redeem according to the lot size and the number of lots to redeem
  const amountToRedeem = web3.utils
    .toBN(lotSize)
    .mul(web3.utils.toBN(LOTS_TO_REDEEM));
  console.log(
    `Required FXRP amount ${formatUnits(amountToRedeem.toString(), Number(decimals))} FXRP`,
  );
  console.log(`Required amount in base units: ${amountToRedeem.toString()}`);

  // Approve FXRP for redemption
  await approveFAssets(fAssetsRedeem, amountToRedeem.toString());

  // Call redeem function and wait for transaction
  const redeemTx = await fAssetsRedeem.redeem(
    LOTS_TO_REDEEM,
    UNDERLYING_ADDRESS,
  );
  console.log("Redeem transaction receipt", redeemTx);

  // Parse events from the transaction
  const redemptionRequestedEvents = await parseRedemptionEvents(
    redeemTx.receipt,
    fAssetsRedeem,
  );

  // Print redemption request info for each redemption requested event
  await printRedemptionRequestInfo(fAssetsRedeem, redemptionRequestedEvents);
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

Run the Script

To run the script, use the Flare Hardhat Starter Kit with the following command:

npx hardhat run scripts/fassets/getLotSize.ts --network coston2

Once the script is executed, two events hold the important information:

`RedemptionRequested`

The RedemptionRequested event contains the agent vault address, redeemer address, underlying chain address, amount of FAssets to redeem, redemption fee, and other important information.

RedemptionRequested Result {
  '0': '0xaADbF766Fd9131996C7B270A0cCB2b5c88Fc810D',
  '1': '0xDc8B65D8C07825280F2A2E08D5b25B9eea892E8f',
  '2': '6797056',
  '3': 'rSHYuiEvsYsKR8uUHhBTuGP5zjRcGt4nm',
  '4': '10000000',
  '5': '50000',
  '6': '9113416',
  '7': '9113939',
  '8': '1753190628',
  '9': '0x464250526641000200000000000000000000000000000000000000000067b700',
  '10': '0x0000000000000000000000000000000000000000',
  '11': '0',
  __length__: 12,
  agentVault: '0xaADbF766Fd9131996C7B270A0cCB2b5c88Fc810D',
  redeemer: '0xDc8B65D8C07825280F2A2E08D5b25B9eea892E8f',
  requestId: '6797056',
  paymentAddress: 'rSHYuiEvsYsKR8uUHhBTuGP5zjRcGt4nm',
  valueUBA: '10000000',
  feeUBA: '50000',
  firstUnderlyingBlock: '9113416',
  lastUnderlyingBlock: '9113939',
  lastUnderlyingTimestamp: '1753190628',
  paymentReference: '0x464250526641000200000000000000000000000000000000000000000067b700',
  executor: '0x0000000000000000000000000000000000000000',
  executorFeeNatWei: '0'
}

When decoding an event, the most important data from the event is:

The agent vault address that will redeem the FAssets is 0x3c831Fe4417bEFFAc721d24996985eE2dd627053;
The redeemer address is 0xCA7C9fBbA56E44C508bcb4872775c5fEd169cDb3;
The redemption ticket id is 1898730;
The underlying chain address is rSHYuiEvsYsKR8uUHhBTuGP5zjRcGt4nm;
The amount of FAssets to redeem is 20000000;
The redemption fee is 20000;

You can view the full event description here.

`RedemptionTicketUpdated`

The event RedemptionTicketUpdated contains the redemption ticket information, including the agent vault address, redemption ticket ID, and the value of the redemption ticket in the underlying chain currency.

For every minting, a redemption ticket is created, and during the redemption process, the redemption ticket is updated with the new redemption status.

RedemptionTicketUpdated Result {
  '0': '0xaADbF766Fd9131996C7B270A0cCB2b5c88Fc810D',
  '1': '1628',
  '2': '5360000000',
  __length__: 3,
  agentVault: '0xaADbF766Fd9131996C7B270A0cCB2b5c88Fc810D',
  redemptionTicketId: '1628',
  ticketValueUBA: '5360000000'
}

Once decoding the most important data from the event is:

The agent vault address that will redeem the FAssets is 0x3c831Fe4417bEFFAc721d24996985eE2dd627053;
The redemption ticket id is 870;
The value of the redemption ticket in underlying chain currency is 3440000000 (partially redeemed).

You can read the full event description here.

Agent Process

The FAssets agent should perform the redemption, and the user must retrieve the redeemed assets from the agent.

If the agent is unable to redeem the assets on the underlying chain in the specified time. In that case, the user can execute the redemptionPaymentDefault function to receive compensation from the agent's collateral.

Next Steps

tip

This is only the first step of the redemption process. The redeemer or agent completes the redemption process when proof of payment is presented to the FAssets system. Read more about the redemption process in the here.

Overview​

Prerequisites​

Redeem FAssets Smart Contract​

Code Breakdown​

Deploy and Interact with the Smart Contract​

Import the Required Contracts​

Define the Constants​

Import Contract Artifacts​

Deploy and Verify the Redeem Contract​

Approve the FXRP transfer to the Redeem Contract​

Parse the Redemption Events​

Output the Redemption Result​

Redeeming FAssets​

Run the Script​

RedemptionRequested​

RedemptionTicketUpdated​

Agent Process​

Next Steps​