Create

Programming the trading liquidity

After agreeing to the trade, buyer opens a set of payment streams as per the payment schedule of the agreement.

When creating a new payment stream, the buyer sets:

• Total amount to be paid out in aggregate

• Initial amount the buyer collateralises the stream with

• Start date the stream is to start flowing

• Maturity date of the stream, when the Total amount is to have been transferred

Upon creating the stream, the buyer must approve a transfer from their balance to the balance of the escrow contract. The approved amount must be the initial amount.

const target_amount = toUint256WithFelts((BigInt('10,000'.replace(/,/g, ''))).toString())
const initial_amount = toUint256WithFelts((BigInt('5,000'.replace(/,/g, ''))).toString())

await buyer.invoke(
    txFlowContract, 
    'approve', 
    { spender: txFlowContract.address, amount: initial_amount}, 
    { maxFee: FEE}
  )

The following code shows the stream creation process which is executed after the approval above:

const {block_number: block, block_timestamp: time} = await account0.call(txFlowContract, "state")

let block_timestamp = new Date(Number(time) * 1000)

let start_timestamp = new Date(block_timestamp)
let start_unixtime = Math.floor(start_timestamp.getTime() / 1000)

let maturity_timestamp = start_timestamp
maturity_timestamp.setMinutes(start_timestamp.getMinutes() + 35)
let maturity_unixtime = Math.floor(maturity_timestamp.getTime() / 1000)

let tokenId = toUint256WithFelts("0")

let txHash = await buyer.invoke(
      txFlowContract, 
      "addNFTMaturityStream", 
      { 
            beneficiary_address: txTradeContract.address, 
            beneficiary_tokenId: tokenId, 
            target_amount: target_amount, 
            initial_amount: initial_amount, 
            start: start_unixtime, 
            maturity: maturity_unixtime 
      }, 
      { maxFee: FEE}
    )

console.log('Tx: ', txHash)
let txReceipt = await starknet.getTransactionReceipt(txHash)
let flowId = parseInt(txReceipt['events'][0]['data'][0], 16)
console.log('Flow ID: ', flowId)

After the stream has been opened, the flowId in the code above (towards the end of the code block) is the stream identifier used to control it.