BDEX V2

BDEX V2 is a Constant Product AMM (x × y = k) deployed on BOT Chain, based on the battle-tested Uniswap V2 architecture. It provides a simple and reliable DEX infrastructure for token creators and developers.

Creating Trading Pairs

BDEX V2 trading pairs are created through the V2 Factory contract. A pair is uniquely identified by two token addresses, and each token pair can only have one V2 pair contract.

Factory method:

function createPair(address tokenA, address tokenB) external returns (address pair);
function getPair(address tokenA, address tokenB) external view returns (address pair);

Basic rules:

• tokenA and tokenB must be different tokens.

• Neither token address can be the zero address.

• If the pair already exists, createPair will revert.

• After creation, developers can read the pair address through getPair(tokenA, tokenB) or listen to the PairCreated event.

Example flow:

const pair = await factory.getPair(tokenA, tokenB)

if (pair === ZERO_ADDRESS) {
  const tx = await factory.createPair(tokenA, tokenB)
  await tx.wait()
}

For most frontend integrations, developers do not need to manually create the pair first. Adding initial liquidity through the router can create the pair when needed.

Adding / Removing Liquidity

BDEX V2 liquidity is managed through the V2 Router02 contract. Liquidity providers deposit both tokens into a pair and receive V2 LP tokens. The LP token is the pair contract's ERC-20 token and represents the provider's share of the pool.

Common methods:

function addLiquidity(
  address tokenA,
  address tokenB,
  uint amountADesired,
  uint amountBDesired,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);

function removeLiquidity(
  address tokenA,
  address tokenB,
  uint liquidity,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external returns (uint amountA, uint amountB);

Integration notes:

• Users must approve the V2 Router02 to spend both ERC-20 tokens before adding liquidity.

• For an existing pool, liquidity should be added according to the current reserve ratio.

• For a new pool, the first liquidity provider defines the initial price by choosing the deposit ratio.

• amountAMin and amountBMin should be set to protect users from slippage.

• Removing liquidity burns LP tokens and returns the underlying token pair according to the user's pool share.

Native BOT liquidity:

For pools involving native BOT, use the ETH-style router methods such as addLiquidityETH / removeLiquidityETH. Internally, native BOT is wrapped as WBOT.

Token Swap Guide

BDEX V2 swaps can be executed directly through Router02, but frontend applications are recommended to use the official Routing API to get the best route and executable calldata.

Recommended integration path:

1. Call the Routing API GET /quote.

2. Read methodParameters.to, methodParameters.calldata, and methodParameters.value from the response.

3. Submit these fields with eth_sendTransaction.

Routing API example:

GET /quote?chainId=677
  &tokenInAddress=0x...
  &tokenOutAddress=0x...
  &amount=1000000000000000000
  &type=exactIn
  &protocols=v2
  &recipient=0x...
  &slippageTolerance=0.5

Direct Router02 methods:

function swapExactTokensForTokens(
  uint amountIn,
  uint amountOutMin,
  address[] calldata path,
  address to,
  uint deadline
) external returns (uint[] memory amounts);

function swapTokensForExactTokens(
  uint amountOut,
  uint amountInMax,
  address[] calldata path,
  address to,
  uint deadline
) external returns (uint[] memory amounts);

Swap fee:

• BDEX V2 uses a fixed 0.30% swap fee.

• The fee is taken from the input token amount.

• The output token is not charged by the pool separately.

• Fees remain in the pool and are distributed to LPs through the pool reserve growth.

Fee-on-transfer tokens:

Fee-on-transfer tokens should only use V2 routes. V3 liquidity and swap flows may revert for tax tokens. The Routing API automatically detects supported fee-on-transfer cases and restricts routing when needed.