Constants

Global constants and types used throughout the SDK.

Import

import {
  TradeType,
  Rounding,
  MaxUint256,
  toBigInt,
  type BigintIsh,
} from '@uniswap/sdk-core-next'

Types

`BigintIsh`

A type that can be converted to bigint.

type BigintIsh = bigint | string | number

import { toBigInt, type BigintIsh } from '@uniswap/sdk-core-next'
 
const a: BigintIsh = 100n
const b: BigintIsh = '100'
const c: BigintIsh = 100
 
toBigInt(a) // 100n
toBigInt(b) // 100n
toBigInt(c) // 100n

Enums

`TradeType`

Direction of a trade.

enum TradeType {
  EXACT_INPUT = 0,
  EXACT_OUTPUT = 1,
}

Value	Description
`EXACT_INPUT`	The input amount is fixed, output varies
`EXACT_OUTPUT`	The output amount is fixed, input varies

import { TradeType } from '@uniswap/sdk-core-next'
 
// Exact input: "Swap exactly 1 ETH for USDC"
const tradeType = TradeType.EXACT_INPUT
 
// Exact output: "Swap ETH to get exactly 2000 USDC"
const tradeType = TradeType.EXACT_OUTPUT

`Rounding`

Rounding mode for decimal operations.

enum Rounding {
  ROUND_DOWN = 0,
  ROUND_HALF_UP = 1,
  ROUND_UP = 2,
}

Value	Description
`ROUND_DOWN`	Truncate toward zero
`ROUND_HALF_UP`	Round half away from zero (standard rounding)
`ROUND_UP`	Always round away from zero

import { Fraction, Rounding } from '@uniswap/sdk-core-next'
 
const f = new Fraction(5, 3) // 1.666...
 
f.toFixed(1, {}, Rounding.ROUND_DOWN)    // "1.6"
f.toFixed(1, {}, Rounding.ROUND_HALF_UP) // "1.7"
f.toFixed(1, {}, Rounding.ROUND_UP)      // "1.7"
 
const f2 = new Fraction(3, 2) // 1.5
f2.toFixed(0, {}, Rounding.ROUND_DOWN)    // "1"
f2.toFixed(0, {}, Rounding.ROUND_HALF_UP) // "2"
f2.toFixed(0, {}, Rounding.ROUND_UP)      // "2"

Constants

`MaxUint256`

Maximum value for a uint256.

const MaxUint256 = 2n ** 256n - 1n

import { MaxUint256 } from '@uniswap/sdk-core-next'
 
console.log(MaxUint256)
// 115792089237316195423570985008687907853269984665640564039457584007913129639935n
 
// Common use: approval amounts
const UNLIMITED_APPROVAL = MaxUint256

Functions

`toBigInt(value)`

Safely converts a BigintIsh value to bigint.

function toBigInt(value: BigintIsh): bigint

import { toBigInt } from '@uniswap/sdk-core-next'
 
// From bigint
toBigInt(100n) // 100n
 
// From string (decimal)
toBigInt('100') // 100n
 
// From string (hex)
toBigInt('0x64') // 100n
 
// From number
toBigInt(100) // 100n
 
// Non-integer number throws
toBigInt(1.5) // throws "Cannot convert non-integer 1.5 to bigint"