Transaction format and fee rate

Fee rate
The current standard fee rate which applies to all transactions submitted to any of the TAAL transaction processing APIs is: 1 sat/kb
The minimum fee for any transaction is 1 sat.
The fee required is rounded depending on size of the transaction. The following list exemplifies the logic:
Transactions with 1.4999... kb > size > 0.0 kb => min absolute fee required = 1 sat. 
Transactions with 2.4999... kb > size > 1.5 kb => min absolute fee required = 2 sat
Transactions with 3.4999... kb > size > 2.5 kb => min absolute fee required = 3 sat
...
Transaction format
The format of transaction is bound to the standard of BSV transactions as described here.
There is a number of libraries which allow to build BSV transactions. Here is a short list:
​https://www.npmjs.com/package/bsv​
​https://github.com/libsv/go-bt​
Javascript example using version 1 of bsv.js and request modules
1.Create a new Node.js project:
mkdir example
cd example
npm init -y
npm install bsv@1
npm install request
2.Save the following code to a main.js in your example folder:
const fs = require('fs')
const bsv = require('bsv')
​
// Random key produced each time...
const newKey = bsv.PrivateKey()
​
console.log(`Private key: ${newKey.toString()}`)
console.log(`Mainnet address: ${newKey.toAddress('mainnet').toString()}`)
​
console.log(`
1. Create a funding transaction by sending 1000 satoshis (0.00001 BSV) to ${newKey.toAddress('mainnet').toString()}.
​
2. Add your Taal apiKey, and funding transaction txid and vout to 'generated.js'.
​
3. Execute the generated code:
​
 node generated.js
​
`)
​
​
fs.writeFileSync('generated.js', `
const bsv = require('bsv')
var request = require('request')
​
const privKey = bsv.PrivateKey('${newKey}')
​
const apiKey = "" // Add Taal mainnet API Key
const fundingTxid = "" // Add the funding transaction txid
const fundingVout = -1 // Replace with funding transaction vout
const returnAddress = "" // The address to return the 1000 satoshis (less fees)
​
if (apiKey === "" || fundingTxid === "" || fundingVout === -1 || returnAddress === "") {
 console.log('This generated file needs an apiKey, a fundingTxid, a fundingVout and a returnAddress')
 process.exit(1)
}
​
const utxo1 = {
 txId: fundingTxid,
 outputIndex: fundingVout,
 address: privKey.toAddress('mainnet').toString(),
 script: bsv.Script.buildPublicKeyHashOut(privKey.publicKey).toHex(),
 satoshis: 1000
}
​
const tx1 = bsv.Transaction()
 .from(utxo1)
 .to(privKey.toAddress('mainnet').toString(), 800)
 .change(returnAddress)
 .sign(privKey)
​
const utxo2 = {
 txId: tx1.hash,
 outputIndex: 0,
 address: privKey.toAddress('mainnet').toString(),
 script: bsv.Script.buildPublicKeyHashOut(privKey.publicKey).toHex(),
 satoshis: 800
}
​
const tx2 = bsv.Transaction()
 .from(utxo2)
 .change(returnAddress)
 .sign(privKey)
 
​
const txBuffer = Buffer.concat([
 tx1.toBuffer(),
 tx2.toBuffer()
])
​
// Send the transaction to Taal API...
request.post({
 url: 'https://api.taal.com/api/v1/batchBroadcast',
 headers: {
 'Authorization': apiKey,
 'Content-Type': 'application/octet-stream'
 },
 body: txBuffer
}, function(error, response, body) {
 console.log(error, response.statusCode, body)
})
`)
3.Execute the code and follow the onscreen instructions:
node main.js 
Last modified 3mo ago