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

Warn

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:

Declare an instance of the XATA module.

import { Xata } from '@xatadev/sdk';
    
const xataApi = new Xata();

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)

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 <= (`amountBDesired`/`amountADesired`)
amountBDesired	`ethers.BigNumber`	The amount of B added to the liquidity pool if the A/B price <= (`amountADesired`/`amountBDesired`)
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¶

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

await xataApi.swapExactTokensForTokens(<param>)

Parameter	Type	Description
amountln	`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	`unit256`	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);