Pool Creation Guide

This guide demonstrates how to create a new BEX pool using the PoolCreationHelper contract. The PoolCreationHelper is a Relayer allowing pools to be created and joined in a single transaction, simplifying the pool creation process.

For more comprehensive pool creation examples, see the pool creation examples in the BEX SDK repository.

Requirements

Before creating a pool, you’ll need the addresses of tokens you want to include in your pool and tokens to join the pool.

Example: creating a weighted pool

In this example, we’ll create a 50/50 HONEY-WBTC weighted pool using Ethers.js. Following pool creation, the pool will be joined with 1 HONEY and 0.0001 WBTC.

import { ethers } from "ethers";

// Initialize provider and wallet
const provider = new ethers.JsonRpcProvider(RPC_URL);
const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider);

// Pool parameters
const poolName = "HONEY-WBTC-WEIGHTED";
const poolSymbol = "50HONEY-50WBTC";
const createPoolTokens = [honeyToken.address, wbtcToken.address].sort((a, b) =>
  a.toLowerCase() < b.toLowerCase() ? -1 : 1
);

// 50-50 weights (must add up to 1e18)
const normalizedWeights = [ethers.parseUnits("0.5", 18), ethers.parseUnits("0.5", 18)];

// Initial liquidity amounts
const amountsIn = [
  ethers.parseUnits("1", 18), // 1 HONEY (18 decimals)
  ethers.parseUnits("0.0001", 8), // 0.0001 WBTC (8 decimals)
];

Step 1 - approve the PoolCreationHelper

The PoolCreationHelper must be approved as a relayer in the Vault contract:

const vault = new ethers.Contract(
  VAULT_ADDRESS,
  ["function setRelayerApproval(address sender, address relayer, bool approved)"],
  wallet
);

await vault.setRelayerApproval(
  wallet.address, // sender
  POOL_CREATION_HELPER_ADDRESS, // relayer
  true // approved
);

Step 2 - approve tokens

The Vault contract needs approval to spend your tokens:

for (const [i, tokenAddress] of createPoolTokens.entries()) {
  const tokenContract = new ethers.Contract(
    tokenAddress,
    ["function approve(address spender, uint256 amount)"],
    wallet
  );

  await tokenContract.approve(VAULT_ADDRESS, amountsIn[i]);
}

Step 3 - create and join pool

Finally, create and join the pool in a single transaction. We leverage the function createAndJoinWeightedPool.

const poolCreationHelper = new ethers.Contract(
  POOL_CREATION_HELPER_ADDRESS,
  POOL_CREATION_HELPER_ABI,
  wallet
);

const tx = await poolCreationHelper.createAndJoinWeightedPool(
  poolName,
  poolSymbol,
  createPoolTokens,
  createPoolTokens, // joinPoolTokens same as createPoolTokens
  normalizedWeights,
  createPoolTokens.map(() => ethers.ZeroAddress), // no rate providers
  ethers.parseUnits("0.01", 18), // 1% swap fee
  amountsIn,
  wallet.address, // pool owner
  ethers.keccak256(ethers.toUtf8Bytes(`${poolName}-${wallet.address}`)) // salt
);

Overview

Getting Started

Proof of Liquidity

BEX

Bend

Pool Creation Guide

Requirements

Example: creating a weighted pool

Step 1 - approve the PoolCreationHelper

Step 2 - approve tokens

Step 3 - create and join pool

​Requirements

​Example: creating a weighted pool

​Step 1 - approve the PoolCreationHelper

​Step 2 - approve tokens

​Step 3 - create and join pool

Requirements

Example: creating a weighted pool

Step 1 - approve the PoolCreationHelper

Step 2 - approve tokens

Step 3 - create and join pool