# SDK API Reference

# AddLiquidity

This class provides functionality to:

• Perform on-chain queries to see the result of an addLiquidity operation
• Build an addLiquidity transaction, with slippage, for a consumer to submit
• Supported add types: SingleToken, Unbalanced, Proportional
• Supports Balancer v2 & v3

# Example

See the addLiquidity guide and the addLiquidity exampleopen in new window.

# Constructor

const addLiquidity = new AddLiquidity();

# Methods

# query

Simulate addLiquidity operation by using an onchain call.

query(
  input: AddLiquidityInput, 
  poolState: PoolState
): Promise<AddLiquidityQueryOutput>

Parameters

Returns

Promise<AddLiquidityQueryOutput>

AddLiquidityQueryOutputopen in new window - Data that can be passed to buildCall. Includes updated bptOut amount.

# buildCall

Builds the addLiquidity transaction using user defined slippage.

buildCall(input: AddLiquidityBuildCallInput): AddLiquidityBuildCallOutput

Parameters

Returns

AddLiquidityBuildCallOutput

AddLiquidityBuildCallOutputopen in new window - Encoded call data for addLiquidity that user can submit.

# RemoveLiquidity

This class provides functionality to:

• Perform on-chain queries to see the result of an removeLiquidity operation
• Build a removeLiquidity transaction, with slippage, for a consumer to submit
• Supported remove types: Unbalanced, SingleTokenExactOutInput, SingleTokenExactInInput, Proportional
• Supports Balancer v2 & v3

# Example

See the removeLiquidity guide and the removeLiquidity example.

# Constructor

const removeLiquidity = new RemoveLiquidity();

# Methods

# query

Simulate removeLiquidity operation by using an onchain call.

query(
  input: RemoveLiquidityInput,
  poolState: PoolState,
): Promise<RemoveLiquidityQueryOutput>

Parameters

Returns

Promise<RemoveLiquidityQueryOutput>

RemoveLiquidityQueryOutputopen in new window - Data that can be passed to buildCall. Includes updated amountsOut amount.

# queryRemoveLiquidityRecovery

Calculates proportional exit using pool state. Note - this does not do an onchain query.

queryRemoveLiquidityRecovery(
  input: RemoveLiquidityRecoveryInput,
  poolState: PoolState,
): Promise<RemoveLiquidityQueryOutput> 

Parameters

Returns

Promise<RemoveLiquidityQueryOutput>

RemoveLiquidityQueryOutputopen in new window - Data that can be passed to buildCall. Includes updated amountsOut amount.

# buildCall

Builds the removeLiquidity transaction using user defined slippage.

buildCall(
  input: RemoveLiquidityBuildCallInput,
): RemoveLiquidityBuildCallOutput

Parameters

Returns

RemoveLiquidityBuildCallOutput

RemoveLiquidityBuildCallOutputopen in new window - Encoded call data for addLiquidity that user can submit.

# Swap

This class provides functionality to:

• Perform on-chain queries to see the result of a Swap operation
• Build a Swap transaction, with slippage, for a consumer to submit
• Supports Balancer v2 & v3

# Example

See the swap guide swap exampleopen in new window.

# Constructor

const swap = new Swap(swapInput: SwapInput);

Note: SwapInput data is normally returned from an API SOR query but may be constructed manually.

# Methods

# query

Gets up to date swap result by querying onchain.

query(
  rpcUrl?: string,
  block?: bigint,
): Promise<ExactInQueryOutput | ExactOutQueryOutput> 

Parameters

Returns

Promise<ExactInQueryOutput | ExactOutQueryOutput>

ExactInQueryOutputopen in new windowExactOutQueryOutputopen in new window

The updated return for the given swap, either expectedAmountOut or expectedAmountIn depending on swap kind.

# buildCall

Builds the swap transaction using user defined slippage.

buildCall(
  input: SwapBuildCallInput,
): SwapBuildOutputExactIn | SwapBuildOutputExactOut

Parameters

Returns

SwapBuildOutputExactIn | SwapBuildOutputExactOut

SwapBuildOutputExactInopen in new windowSwapBuildOutputExactOutopen in new window

RemoveLiquidityBuildCallOutputopen in new window - Encoded call data for swap that user can submit. Includes minAmountOut or maxAmountIn depending on swap kind.

# quote

Gives the combined return amount for all paths. Note - this always uses the original path amounts provided in constructor and does not get updated.

public get quote(): TokenAmount

Returns

TokenAmount

TokenAmountopen in new window - Gives the combined return amount for all paths (output amount for givenIn, input amount for givenOut).

# inputAmount

public get inputAmount(): TokenAmount

Returns

TokenAmount

TokenAmountopen in new window - Gives the combined input amount for all paths.

# outputAmount

public get outputAmount(): TokenAmount

Returns

TokenAmount

TokenAmountopen in new window - Gives the combined output amount for all paths.

# queryCallData

public queryCallData(): string

Returns

string

Encoded query data for swap that a user can call to get an updated amount.

# PriceImpact

This class provides helper functions to calculate Price Impact for add/remove/swap actions.

• Supports Balancer v2 & v3

# Example

See the price impact exampleopen in new window.

# Methods

# addLiquiditySingleToken

Calculate price impact on add liquidity single token operations.

addLiquiditySingleToken(
  input: AddLiquiditySingleTokenInput,
  poolState: PoolState,
): Promise<PriceImpactAmount> 

Parameters

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# addLiquidityUnbalanced

Calculate price impact on add liquidity unbalanced operations.

addLiquidityUnbalanced = async (
    input: AddLiquidityUnbalancedInput,
    poolState: PoolState,
): Promise<PriceImpactAmount>

Parameters

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# addLiquidityNested

Calculate price impact on add liquidity nested token operations.

addLiquidityNested = async (
  input: AddLiquidityNestedInput,
  nestedPoolState: NestedPoolState,
): Promise<PriceImpactAmount>

Parameters

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# removeLiquidity

Calculate price impact on remove liquidity operations.

removeLiquidity = async (
  input:
      | RemoveLiquiditySingleTokenExactInInput
      | RemoveLiquidityUnbalancedInput,
  poolState: PoolState,
): Promise<PriceImpactAmount>

Parameters

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# removeLiquidityNested

Calculate price impact on remove liquidity single token nested operations.

removeLiquidityNested = async (
  input: RemoveLiquidityNestedSingleTokenInput,
  nestedPoolState: NestedPoolState,
): Promise<PriceImpactAmount>

Parameters

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# swap

Calculate price impact on swap operations.

swap = async (
  swapInput: SwapInput,
  rpcUrl?: string,
  block?: bigint,
): Promise<PriceImpactAmount>

Parameters

Note: SwapInput data is normally returned from an API SOR query but may be constructed manually.

Returns

Promise<PriceImpactAmount>

PriceImpactAmountopen in new window - Price impact for operation.

# BalancerApi

This class provides helper functions for interacting with the Balancer API.

# Example

See the examples for add/remove/swap linked above as these use BalancerApi to fetch required data.

# Constructor

const balancerApi = new BalancerApi(balancerApiUrl: string, chainId: ChainId);

# Methods

# pools.fetchPoolState

Finds state of given pool.

pools.fetchPoolState(id: string): Promise<PoolState> 

Parameters

Returns

Promise<PoolState>

PoolStateopen in new window - State of given pool.

# pools.fetchPoolStateWithBalances

Finds state of given pool including token balances and pool shares.

fetchPoolStateWithBalances(
  id: string,
): Promise<PoolStateWithBalances> 

Parameters

Returns

Promise<PoolStateWithBalances>

PoolStateWithBalancesopen in new window - State of given pool including token balances and pool shares.

# nestedPools.fetchPoolState

Finds state of a set of nested pools.

fetchNestedPoolState(id: string): Promise<NestedPoolState>

Parameters

Returns

Promise<NestedPoolState>

NestedPoolStateopen in new window - state of a set of nested pools.

# sorSwapPaths.fetchSorSwapPaths

Finds optimised swap paths for a given swap config.

fetchSorSwapPaths(sorInput: SorInput): Promise<Path[]>

Parameters

Returns

Promise<Path[]>

Path[]open in new window - optimised swap paths for the given swap.

# Utils

Helper functions.

# calculateProportionalAmounts

Given pool balances (including BPT) and a reference token amount, it calculates all other amounts proportional to the reference amount.

# Example

See the price impact exampleopen in new window.

calculateProportionalAmounts(
  pool: {
    address: Address;
    totalShares: HumanAmount;
    tokens: { 
      address: Address; 
      balance: HumanAmount; 
      decimals: number 
    }[];
  },
  referenceAmount: InputAmount,
): {
  tokenAmounts: InputAmount[];
  bptAmount: InputAmount;
}

Parameters

Returns

{
  tokenAmounts: InputAmount[];
  bptAmount: InputAmount;
}

Amounts proportional to the reference amount.