SDK

The XATA-API module

The source code for this module can be found here on Github, inside the ./src/xata-api directory.

Each function within this module bundles the process of EIP712 signing, fee token calculation, and submitting meta transaction into a single workflow. The supported functions are the following:

• addLiquidity()

• swapExactTokensForTokens()

• swapTokensForExactTokens()

• removeLiquidity()

Using this module, developers no longer required to manually construct a transaction request that looks like this:

{
    "method": "POST",
    "headers": 
    {
        "Content-Type": "application/json"
    },
    "body": 
    "{\"jsonrpc\":\"2.0\",\"method\":\"/v2/metaTx/swapTokensForExactTokens\",\"id\":1,\"params\":[\"137\",{\"types\":{\"EIP712Domain\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"version\",\"type\":\"string\"},{\"name\":\"chainId\",\"type\":\"uint256\"},{\"name\":\"verifyingContract\",\"type\":\"address\"}],\"Forwarder\":[{\"name\":\"from\",\"type\":\"address\"},{\"name\":\"feeToken\",\"type\":\"address\"},{\"name\":\"maxTokenAmount\",\"type\":\"uint256\"},{\"name\":\"deadline\",\"type\":\"uint256\"},{\"name\":\"nonce\",\"type\":\"uint256\"},{\"name\":\"data\",\"type\":\"bytes\"},{\"name\":\"hashedPayload\",\"type\":\"bytes32\"}]},\"domain\":{\"name\":\"ConveyorV2\",\"version\":\"1\",\"chainId\":\"0x89\",\"verifyingContract\":\"0xe4C5Cf259351d7877039CBaE0e7f92EB2Ab017EB\"},\"primaryType\":\"Forwarder\",\"message\":{\"from\":\"0x10D73FE8e15414E7F1468eeb7A5A61A1aeec00C8\",\"feeToken\":\"0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174\",\"maxTokenAmount\":\"0x01\",\"deadline\":\"0x6179545d\",\"nonce\":\"0x20\",\"data\":\"0xf208e6ab000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000f424000000000000000000000000000000000000000000000000000000000000f185900000000000000000000000000000000000000000000000000000000000000a000000000000000000000000010d73fe8e15414e7f1468eeb7a5a61a1aeec00c8000000000000000000000000000000000000000000000000000000006179545d00000000000000000000000000000000000000000000000000000000000000020000000000000000000000002791bca1f2de4661ed88a30c99a7a9449aa84174000000000000000000000000c2132d05d31c914a87c6611c10748aeb04b58e8f\",\"hashedPayload\":\"0x5d299a1b988679b037e32d430bf2fbf03d5eb93949968c076c745ff2ffc18fe3\"}},\"28\",\"0xd8d7fdacaec4de579ee45c079cea896b576e994539f7980ec2ffb0c268fc07e3\",\"0x30dec79f68543f5785931f729ced63aabf5bc26219a11031150bced204d78ece\"]}"
}

---

Installation

To use XATA-API module, you must first install the XATA SDK package from NPM.

$ yarn add @xatadev/sdk

We recommend you use Yarn to run the installation. If you prefer to use NPM (as some of us do!), just run the installation using this command:

$ npm i @xatadev/sdk

⚠️ It's best not to mix up the use of package managers to avoid resolution inconsistencies. Talk to your team and ask which package manager they are using.

---

Getting Started

To use the module, simply do the following 3 steps:

1. Declare an instance of the XATA module.

import { Xata } from '@xatadev/sdk';

const xataApi = new Xata();

1. Initiate the instance

const feeToken = '<0xAddress>'
await xataApi.init(web3Provider, feeToken)

// use this method to change the fee token
const otherFeeToken = '<0xOtherAddress>'
await xataApi.setFeeToken(otherFeeToken)

1. Interact with XATA

You may now interact with the XATA router using Uniswap-like functions. These functions return API responses like the one below:

// response example
{
    "jsonrpc": "2.0",
    "result": {
        "errorMessage": null,
        "success": true,
        "txnHash": "0x3a130c90692053f412a26f6d7914bb7637f0193c0a7054621d3e3c3a7d13c24a"
    },
    "id": 1
}

We'll take a closer look at these functions in the following section.

---

Router Methods

Add Liquidity

Adds liquidity to the pool. If liquidity for the supplied pair does not exist in the pool then this router will initiate liquidity creation automatically.

await xataApi.addLiquidity(<params>)

Parameter	Type	Description
tokenA	string	Token A address
tokenB	string	Token B address
amountADesired	ethers.BigNumber	The amount of A added to the liquidity pool if the B/A price <= (amountofBDesired / amountofADesired) price
amountBDesired	ethers.BigNumber	The amount of B added to the liquidity pool if the A/B price <= (amountofADesired / amountofBDesired) price
amountAMin	ethers.BigNumber	Bounds the extent to which the B/A price can go up before the transaction reverts. Must be <= amountADesired
amountBMin	ethers.BigNumber	Bounds the extent to which the A/B price can go up before the transaction reverts. Must be <= amountBDesired
user	string	The user's address. The liquidity provider and the recipient of LP tokens
deadline	BigNumber	Unix timestamp after which the transaction is reverted
gasLimit	BigNumber	Optional: Gas limit for calculating the token fee amount. This value may not be the actual gas limit used in the transaction
gasPrice	BigNumber	Optional: Gas price for calculating the token fee amount. This value may not be the actual gas price used in the transaction

Swap Exact Tokens For Tokens

Swaps an exact amount of input tokens for as many output tokens as possible.

await xataApi.swapExactTokensForTokens(<params>)

Parameter	Type	Description
amountIn	ethers.BigNumber	The amount of input tokens to send
amountOutMin	ethers.BigNumber	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[]	An array of token addresses. path.length >= 2
user	address	The user's address
deadline	uint256	Unix timestamp after which the transaction is reverted
gasLimit	BigNumber	Optional: Gas limit for calculating the token fee amount. This value may not be the actual gas limit used in the transaction
gasPrice	BigNumber	Optional: Gas price for calculating the token fee amount. This value may not be the actual gas price used in the transaction

Swap Tokens For Exact Tokens

Receive an exact amount of output tokens for as few input tokens as possible.

await xataApi.swapTokensForExactTokens(<params>)

Parameter	Type	Description
amountOut	ethers.BigNumber	The amount of output tokens to receive
amountInMax	ethers.BigNumber	The maximum amount of input tokens that must be sent for the transaction not to revert.
path	address[]	An array of token addresses. path.length >= 2
user	address	The user's address
deadline	uint256	Unix timestamp after which the transaction is reverted
gasLimit	BigNumber	Optional: Gas limit for calculating the token fee amount. This value may not be the actual gas limit used in the transaction
gasPrice	BigNumber	Optional: Gas price for calculating the token fee amount. This value may not be the actual gas price used in the transaction

Remove Liquidity

Withdraws a pair of tokens by burning LP tokens. This method consists of a 2-steps flow; it requires the LP holders to first sign a permit message, allowing the router to burn LP tokens, then proceeds with the actual LP tokens removal.

First, sign the message by calling the permitLP function. (No gas required)

await xataApi.permitLP(<params>)

Parameter	Type	Description
pairAddr	string	The LP token address
owner	string	The owner of the LP tokens. A.k.a. the user's address
spender	string	The recipient address for the allowance. (XATA Router address)
value	ethers.BigNumber	The liquidity value to approve
nonce	ethers.BigNumber	The nonce used for signing the message
deadline	uint256	Unix timestamp after which the transaction is reverted

It will return a Signature object that is required for removing liquidity.

{
  "v": number,
  "r": string,
  "s": string
}

Once you receive the signature object from the permitLP then you can invoke the removeLiquidity function to withdraw tokens.

await xataApi.removeLiquidity(<params>)

Parameter	Type	Description
tokenA	string	Token A address
tokenB	string	Token B address
liquidity	ethers.BigNumber	The amount of liquidity to remove
amountAMin	ethers.BigNumber	The amount of tokenA that must be received before the transaction reverts
amountBMin	ethers.BigNumber	The amount of tokenB that must be received before the transaction reverts
user	string	The user's address. The liquidity provider and the recipient of LP tokens
deadline	BigNumber	Unix timestamp after which the transaction is reverted
sig	SignatureLike	A signature object received from permitLP()
gasLimit	BigNumber	Optional: Gas limit for calculating the token fee amount. This value may not be the actual gas limit used in the transaction
gasPrice	BigNumber	Optional: Gas price for calculating the token fee amount. This value may not be the actual gas price used in the transaction

---

Relay Config

When a transaction request is successfully sent to one of the API routers, the transaction is forwarded and processed by Geode – one of our technologies that can increase privacy and eliminate trading MEV. To do this, the XATA SDK stores the Geode relay configuration as part of the API module.

...
[ChainId.MATIC]: 'https://conveyor-prod-matic.ata.network',
[ChainId.BSC]: 'https://conveyor-prod-bsc.ata.network',
...

Developers can freely customize these endpoints to meet their application needs. To customize it, set new endpoint value(s) for each chain that is supported by your app. You can find the config here.

Using a Test Relay on Development

XATA API works on production mode by default, and therefore the transaction request also gets forwarded to production-grade Geode. If you are under the development stage and want to test the transaction on a separate relay, you need to make a couple of changes.

Update the relay configuration as in the previous section. What makes it different from the previous one is that you have to set the endpoint value(s) under the Environment.STAGING object instead of Environment.PRODUCTION.

[Environment.PRODUCTION]: {
    ...
    [ChainId.MATIC]: 'https://conveyor-prod-matic.ata.network',
    [ChainId.BSC]: 'https://conveyor-prod-bsc.ata.network',
    ...
},
[Environment.STAGING]: {
    ...
    [ChainId.MATIC]: 'https://your-test-relay.endpoint',
    [ChainId.BSC]: 'https://your-test-relay.endpoint',
    ...
}

Update the XATA initiation code on your app.

// Add new Environment enum import
import { Environment, XATA } from '@xatadev/sdk'

const xataApi = new Xata();
const feeToken = '<0xAddress>'

// Add 3rd param to override the SDK env mode
await xataApi.init(web3Provider, feeToken, Environment.STAGING)