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Usage

How to use the SDK to create quotes and bridge transactions.

Setting up your Environment​

In order to begin constructing bridge related transactions, developers need to set up their environment for the relevant chains. The first is configuring chains and providers.

//Set up providers (RPCs) for each chain desired

const arbitrumProvider: Provider = new etherProvider.JsonRpcProvider(
  'https://arb1.arbitrum.io/rpc'
)
const avalancheProvider: Provider = new etherProvider.JsonRpcProvider(
  'https://api.avax.network/ext/bc/C/rpc'
)

//Structure arguments properly
const chainIds = [42161, 43114]
const providers = [arbitrumProvider, avalancheProvider]

//Set up a SynapseSDK instance
const Synapse = new SynapseSDK(chainIds, providers)

In the code snippet above, we set up the different providers and format them, along with the Ids of the chains we are bridging from/to for our quotes.

Functions​

bridgeQuote()​

Getting a bridge quote returns all relevant information regarding a possible transaction. Every bridge transaction requires this step.

Parameters​

  • originChainId - An integer representing the origin chain ID.
  • destChainId - An integer representing the destination chain ID.
  • tokenIn - A string representing the input token.
  • tokenOut - A string representing the output token.
  • amountIn - A BigintIsh representing the input token amount.

Return Value​

A Promise object that resolves to an object with the following properties:

  • feeAmount (BigNumber): A BigNumber object representing the fee amount for the transaction.
  • feeConfig (FeeConfig): A FeeConfig object representing the fee configuration for the transaction.
  • routerAddress (string): A string representing the address of the router.
  • maxAmountOut (BigNumber): A BigNumber object representing the maximum amount of tokens that can be received from the transaction (after fees).
  • originQuery (Query): A Query object representing the query to the origin SynapseRouter.
  • destQuery (Query): A Query object representing the query to the destination SynapseRouter.
If the permutation of chains and tokens is not supported, the SDK will inform the user.

bridge()​

Returns a prepared transaction so that it may be executed by the client.

Parameters​

  • to (string): The recipient address on the destination chain.
  • originChainId (number): The ID of the origin chain.
  • destChainId (number): The ID of the destination chain.
  • token (string): The token to be bridged.
  • amount (BigintIsh): The amount of tokens to be bridged.
  • originQuery (Query): A Query object containing the origin SynapseRouter query (retrieved using bridgeQuote)
  • destQuery (Query): An Query object containing the destination SynapseRouter query (retrieved using bridgeQuote)

Return Value​

A Promise PopulatedTransaction object is returned with the following attributes populated.

  • to (string): The address the tx is to.
  • data (string): The transaction data.

swapQuote()​

Returns a swap quote containing relevant information about a token swap transaction.

Parameters​

  • chainId (number): The ID of the chain.
  • tokenIn (string): The input token for the swap.
  • tokenOut (string): The output token for the swap.
  • amountIn (BigintIsh): The amount of input tokens.

Return Value​

A Promise object that resolves to an object with the following properties:

  • routerAddress (string | undefined): The address of the router.
  • maxAmountOut (BigNumber | undefined): The maximum amount of output tokens that can be obtained from the swap.
  • query (Query | undefined): A Query object representing the swap query.

swap()​

Executes a token swap transaction on the specified chain.

Parameters​

  • chainId (number): The ID of the chain.
  • to (string): The recipient address for the swapped tokens.
  • token (string): The token to be swapped.
  • amount (BigintIsh): The amount of tokens to be swapped.
  • query (Query): An Query object containing the SynapseRouter swap query (retrieved using swapQuote)

Return Value​

A Promise PopulatedTransaction object is returned with the following attributes populated.

  • to (string): The address the tx is to.
  • data (string): The transaction data.

getBridgeGas()​

Returns the gas amount for the bridge transaction on the specified chain.

Parameters​

  • chainId (number): The ID of the chain.

Return Value​

A Promise object that resolves to a BigintIsh representing the gas amount for the bridge transaction.

getPoolTokens()​

Retrieves the pool tokens associated with a specific pool address on the specified chain.

Parameters​

  • chainId (number): The ID of the chain.
  • poolAddress (string): The address of the pool.

Return Value​

A Promise object that resolves to an array of PoolToken objects representing the pool tokens.

getPoolInfo()​

Retrieves information about a pool identified by its address on the specified chain.

Parameters​

  • chainId (number): The ID of the chain.
  • poolAddress (string): The address of the pool.

Return Value​

A Promise object that resolves to an object with the following properties:

  • tokens (BigNumber | undefined): The number of tokens in the pool.
  • lpToken (string | undefined): The address of the LP (liquidity provider) token associated with the pool.

getAllPools()​

Retrieves information about all pools on the specified chain.

Parameters​

  • chainId (number): The ID of the chain.

Return Value​

A Promise object that resolves to an array of objects, each representing a pool. Each pool object has the following properties:

  • poolAddress (string | undefined): The address of the pool.
  • tokens (PoolToken[] | undefined): An array of PoolToken objects representing the tokens in the pool.
  • lpToken (string | undefined): The address of the LP (liquidity provider) token associated with the pool.

calculateAddLiquidity()​

Calculates the amount of liquidity tokens to be added when providing liquidity to a pool.

Parameters​

  • chainId (number): The ID of the chain.
  • poolAddress (string): The address of the pool.
  • amounts (object): A record of token addresses as keys and their corresponding amounts as values.

Return Value​

A Promise object that resolves to an object with the following properties:

  • amount (BigNumber): The calculated amount of liquidity tokens.
  • routerAddress (string): The address of the router.

calculateRemoveLiquidity()​

Calculates the amounts of tokens to be received when removing liquidity from a pool.

Parameters​

  • chainId (number): The ID of the chain.
  • poolAddress (string): The address of the pool.
  • amount (BigNumber): The amount of liquidity tokens to be removed.

Return Value​

A Promise object that resolves to an object with the following properties:

  • amounts (Record<string, { value: BigNumber; index: number }>): A record of token addresses as keys and their corresponding amounts and index positions as values.
  • routerAddress (string): The address of the router.

calculateRemoveLiquidityOne()​

Calculates the amount of a specific token to be received when removing liquidity from a pool.

Parameters​

  • chainId (number): The ID of the chain.
  • poolAddress (string): The address of the pool.
  • amount (BigNumber): The amount of liquidity tokens to be removed.
  • token (string): The address of the token.

Return Value​

A Promise object that resolves to an object with the following properties:

  • amount ({ value: BigNumber; index: number }): The calculated amount of the specified token and its index position.
  • routerAddress (string): The address of the router.

Types​

Query​

The Query type represents the instructions for the bridge or swap. This type has the following attributes.

  • swapAdapter (string): The address of the swap adapter.
  • tokenOut (string): The address of the outputted token on that chain.
  • minAmountOut (BigNumber): The min amount of value exiting the transaction.
  • deadline (BigNumber): The deadline for the potential transaction.
  • rawParams (string): The raw params for the potential transaction.

FeeConfig​

The FeeConfig type represents the fee data stored in the bridge contract. This type has the following attributes.

  • bridgeFee (number): The bridge fee taken for that query.
  • minFee (BigNumber): The min fee possible for that bridge contract.
  • maxFee (BigNumber): The max fee possible for that bridge contract.

PoolToken​

The PoolToken type represents a pool token with the following attributes.

  • token (string): The token address.
  • isWeth (boolean | undefined): Indicates whether the token is wrapped Ether (WETH).

BigNumber/BigNumberish​

BigNumber and BigNumberish are the ethers v5 BigNumber and BigNumberish types