Withdraw Liquidity

Example of code that withdraw liquidity into Aquarius pool

Python

# withdraw.py

from typing import List

from stellar_sdk import Address, Keypair, scval, SorobanServer, xdr, TransactionBuilder, Server
from stellar_sdk.xdr import UInt128Parts

# ==========================
# Configuration Variables
# ==========================

# Soroban and Horizon server RPC endpoints
SOROBAN_SERVER_RPC = 'https://soroban-testnet.stellar.org:443/'
HORIZON_SERVER = 'https://horizon-testnet.stellar.org'

# Distributor's secret key (ensure this is kept secure)
SECRET = 'SCJF..........KTXQ'

# Contract IDs for the router and tokens
ROUTER_CONTRACT_ID = 'CDMSJQ4TPCTAYDRYN46FVMYIWV2A4ZTHCWWIN2NW3QZIFPJWBBEGDKDY'
TOKEN_A_CONTRACT_ID = 'CAZRY5GSFBFXD7H6GAFBA5YGYQTDXU4QKWKMYFWBAZFUCURN3WKX6LF5'
TOKEN_B_CONTRACT_ID = 'CBL6KD2LFMLAUKFFWNNXWOXFN73GAXLEA4WMJRLQ5L76DMYTM3KWQVJN'

# Stellar network passphrase and known pool hash
NETWORK_PASSPHRASE = 'Test SDF Network ; September 2015'
POOL_HASH = '8328b65c4d32886fb1876be01b4ad13ef5ff14719d7c735d4060da683315473d'


# ==========================
# Utility Functions
# ==========================

def order_token_ids(tokens: List[xdr.SCVal]) -> List[xdr.SCVal]:
   """
   Orders token IDs based on their contract ID to maintain consistency.

   Args:
       tokens (List[xdr.SCVal]): List of token addresses as SCVal objects.

   Returns:
       List[xdr.SCVal]: Ordered list of token SCVal objects.
   """
   return sorted(tokens, key=lambda token: int(token.address.contract_id.hash.hex(), 16))


def u128_to_int(value: UInt128Parts) -> int:
   """
   Converts UInt128Parts from Stellar's XDR to a Python integer.

   Args:
       value (UInt128Parts): UInt128Parts object from Stellar SDK.

   Returns:
       int: Corresponding Python integer.
   """
   return int(value.hi.uint64 << 64) + value.lo.uint64


# ==========================
# Withdraw Function
# ==========================

def execute_withdraw(pool_hash: str):
   """
   Executes the withdraw operation from a specified AMM pool.

   Args:
       pool_hash (str): The known hash of the target AMM pool (32-byte hex string).
   """
   # Initialize Soroban and Horizon servers
   server = SorobanServer(SOROBAN_SERVER_RPC)
   horizon_server = Server(HORIZON_SERVER)

   # Load distributor's keypair using the secret key
   keypair = Keypair.from_secret(SECRET)

   print(f"Initiating withdrawal using router contract ID: {ROUTER_CONTRACT_ID}")

   # Order token IDs to ensure consistency
   token_a = scval.to_address(TOKEN_A_CONTRACT_ID)
   token_b = scval.to_address(TOKEN_B_CONTRACT_ID)
   ordered_tokens = order_token_ids([token_a, token_b])
   token_a, token_b = ordered_tokens

   # Define the amount of liquidity shares to redeem
   # For example, redeeming all shares. Adjust as necessary.
   # You may need to query your current share balance before deciding the amount to withdraw.
   # Here, we assume you want to withdraw a specific amount.
   SHARES_TO_REDEEM = 5_0000000  # Example: 5 shares with 7 decimal places

   print(f"Withdrawing from pool {POOL_HASH}")

   # Load the distributor's account information from Soroban server
   account = server.load_account(keypair.public_key)

   # Build the withdraw transaction
   tx_builder = TransactionBuilder(
       source_account=account,
       network_passphrase=NETWORK_PASSPHRASE,
       base_fee=1000000  # Set base fee; adjust as necessary
   ).set_timeout(3600)  # Set transaction timeout

   # Append the invoke_contract_function operation for withdraw
   tx = tx_builder.append_invoke_contract_function_op(
       contract_id=ROUTER_CONTRACT_ID,
       function_name="withdraw",
       parameters=[
           Address(keypair.public_key).to_xdr_sc_val(),  # Distributor's address
           scval.to_vec([token_a, token_b]),  # Token pair
           scval.to_bytes(bytes.fromhex(pool_hash)),  # Known pool hash as bytes
           scval.to_uint128(SHARES_TO_REDEEM),  # Amount of shares to redeem
           scval.to_vec([
               scval.to_uint128(1),  # Minimum amount of Token A to receive
               scval.to_uint128(1),  # Minimum amount of Token B to receive
           ]),
       ],
   )
   tx = server.prepare_transaction(tx.build())
   tx.sign(keypair)

   tx_response = horizon_server.submit_transaction(tx)
   transaction_meta = xdr.TransactionMeta.from_xdr(tx_response['result_meta_xdr'])
   tx_result = transaction_meta.v3.soroban_meta.return_value
   if not tx_result:
       raise RuntimeError

   amount_a, amount_b = map(u128_to_int, [r.u128 for r in tx_result.vec.sc_vec])
   print("Withdrawal successful!")
   print(f"Received Amounts: Token A = {amount_a}, Token B = {amount_b}")


if __name__ == "__main__":
   execute_withdraw(POOL_HASH)

JavaScript

const binascii = require('binascii');
const StellarSdk = require('@stellar/stellar-sdk');
const {
    Address,
    Contract,
    TransactionBuilder,
    SorobanRpc,
    Horizon,
    BASE_FEE,
    Networks,
    xdr,
    TimeoutInfinite,
    StrKey,
    XdrLargeInt,
    Keypair,
} = StellarSdk;

// ==========================
// Configuration Variables
// ==========================

// Soroban and Horizon server RPC endpoints
const sorobanServerUrl = 'https://soroban-testnet.stellar.org:443/'; //testnet
const horizonServerUrl = 'https://horizon-testnet.stellar.org';

// Distributor's secret key (ensure this is kept secure)
const userSecretKey = 'S...';

// Contract IDs for the router and tokens
const routerContractId = 'CDMSJQ4TPCTAYDRYN46FVMYIWV2A4ZTHCWWIN2NW3QZIFPJWBBEGDKDY'; //testnet
const tokenAContractId = 'CDLZFC3SYJYDZT7K67VZ75HPJVIEUVNIXF47ZG2FB2RMQQVU2HHGCYSC'; // XLM
const tokenBContractId = 'CDNVQW44C3HALYNVQ4SOBXY5EWYTGVYXX6JPESOLQDABJI5FC5LTRRUE'; //AQUA

// Known pool hash
const poolHash = '9ac7a9cde23ac2ada11105eeaa42e43c2ea8332ca0aa8f41f58d7160274d718e' // XLM-AQUA


// ==========================
// Utility Functions
// ==========================

function orderTokensIds(tokensIds) {
    /**
     * Orders token IDs based on their contract ID to maintain consistency.
     *
     * @param {Array} tokensIds - List of token addresses as SCVal objects.
     * @returns {Array} Ordered list of token SCVal objects.
     */
    return tokensIds.sort((a, b) => {
        const aHash = BigInt('0x' + a.address().contractId().toString('hex'));
        const bHash = BigInt('0x' + b.address().contractId().toString('hex'));

        // Compare BigInts directly without converting to number
        if (aHash < bHash) return -1;
        if (aHash > bHash) return 1;
        return 0;
    });
}

function u128ToInt(value) {
    /**
     * Converts UInt128Parts from Stellar's XDR to a JavaScript number.
     *
     * @param {Object} value - UInt128Parts object from Stellar SDK, with `hi` and `lo` properties.
     * @returns {number|null} Corresponding JavaScript number, or null if the number is too large.
     */
    const result = (BigInt(value.hi()._value) << 64n) + BigInt(value.lo()._value);

    // Check if the result is within the safe integer range for JavaScript numbers
    if (result <= BigInt(Number.MAX_SAFE_INTEGER)) {
        return Number(result);
    } else {
        console.warn("Value exceeds JavaScript's safe integer range");
        return null;
    }
}

function contractIdToScVal(contractId) {
    /**
     * Converts a contract ID to a Stellar SCVal (Smart Contract Value) format.
     *
     * @param {string} contractId - The contract ID to convert.
     * @returns {StellarSdk.xdr.ScVal} - The SCVal representation of the contract ID.
     *
     * @throws {Error} Throws an error if the contract ID is invalid or cannot be decoded.
     */
    return StellarSdk.Address.contract(StrKey.decodeContract(contractId)).toScVal();
}



// ==========================
// Withdraw Function
// ==========================


async function executeWithdraw() {
    const sorobanServer = new SorobanRpc.Server(sorobanServerUrl);
    const horizonServer = new Horizon.Server(horizonServerUrl);

    const [tokenA, tokenB] = orderTokensIds([
        contractIdToScVal(tokenAContractId),
        contractIdToScVal(tokenBContractId)
    ]);

    const sharesToRedeem = 2000; // Example: 0.0002 shares
    const sharesToRedeemU128 = new XdrLargeInt('u128', sharesToRedeem.toFixed()).toU128();
    const minimumAmount = new XdrLargeInt('u128', '1').toU128(); // 0.0000001

    const keypair = Keypair.fromSecret(userSecretKey);
    // Load the distributor's account information from Soroban server
    const account = await sorobanServer.getAccount(keypair.publicKey());

    const contract = new Contract(routerContractId);

    const tx = new TransactionBuilder(account, {
        fee: BASE_FEE,
        networkPassphrase: Networks.TESTNET,
    }).addOperation(contract.call(
        'withdraw',
        xdr.ScVal.scvAddress(Address.fromString(keypair.publicKey()).toScAddress()), // Distributor's address
        xdr.ScVal.scvVec([tokenA, tokenB]), // Token pair
        xdr.ScVal.scvBytes(Buffer.from(binascii.unhexlify(poolHash), 'ascii')), // Known pool hash as bytes
        sharesToRedeemU128, // Amount of shares to redeem
        xdr.ScVal.scvVec([minimumAmount, minimumAmount]), // Minimum amounts of Token A and Token B to receive
    )).setTimeout(TimeoutInfinite).build();


    const preparedTx = await sorobanServer.prepareTransaction(tx);

    preparedTx.sign(keypair);

    const result = await horizonServer.submitTransaction(preparedTx);

    const meta = xdr.TransactionMeta.fromXDR(result.result_meta_xdr, 'base64');

    const returnValue = meta.v3().sorobanMeta().returnValue();

    const [withdrawalA, withdrawalB] = returnValue.value().map(value => u128ToInt(value.value()));

    console.log('Withdrawal successful!');
    console.log(`Received Amounts: Token A = ${withdrawalA}, Token B = ${withdrawalB}`);
}

executeWithdraw();