Pair Addresses

get_pair

The most obvious way to get the address for a pair is to call get_pair on the factory. If the pair exists, this function will return its address, else 0x0.

The "canonical" way to determine whether or not a pair exists.
Requires an on-chain lookup.

Off-chain Computation

We can also compute pair addresses without any on-chain lookups .

import { Token } from '@razorlabs/swap-sdk-core'
import { AMM_SIGNER } from '@razorlabs/amm-sdk'
import { AccountAddress, createObjectAddress, Hex } from '@aptos-labs/ts-sdk'
 
const getPairSeed = (token0: Token, token1: Token): string => {
  const validatedToken0Address = AccountAddress.from(token0.address).toStringLong()
  const validatedToken1Address = AccountAddress.from(token1.address).toStringLong()
  if (token0.sortsBefore(token1)) {
    return validatedToken0Address + validatedToken1Address.slice(2)
  } else {
    return validatedToken1Address + validatedToken0Address.slice(2)
  }
}
 
export const computePairAddress = ({ tokenA, tokenB }: { tokenA: Token; tokenB: Token }): string => {
  const rawSeed = getPairSeed(tokenA, tokenB)
  const seed = Hex.fromHexInput(rawSeed).toUint8Array()
  const account = AccountAddress.from(AMM_SIGNER)
  const address = createObjectAddress(account, seed)
 
  return address.toString()
}

token0 must be strictly less than token1 by sort order.

Can be computed offline.