Postman resquest to send a lightning payment using KeySend and the LND REST API

Body.json

{
    "dest": "{{lightning-dest-pubkey-base64}}",
    "amt": "{{lightning-payment-amount}}",
    "timeout_seconds": 60,
    "payment_hash": "{{lightning-payment-hash}}",
    "dest_custom_records": {
        "5482373484": "{{lightning-preimage}}"
    }
}

Documentation.md

References

• LND Source Code References
  • KeySend Preimage Custom Record
  • Preimage
  • lncli keysend handling
• https://api.lightning.community/#v2-router-route-send
• Running a local regtest lightning cluster with docker

pre-request script.js

var encoded;
var hash;
var byteArray = new Uint8Array(32);

var dest_pubkey_hex = pm.variables.get('lightning-dest-pubkey-hex');
var dest_pubkey_base64 = Buffer.from(dest_pubkey_hex, 'hex').toString('base64');
console.log(dest_pubkey_base64)
pm.variables.set('lightning-dest-pubkey-base64', dest_pubkey_base64);

for(let i = 0; i < 32; i++) {
    let randomNumber = _.random(0, 255);
    byteArray[i] = randomNumber;
}

encoded = Buffer.from(byteArray).toString('base64');
hash = CryptoJS.enc.Base64.stringify(CryptoJS.SHA256(CryptoJS.enc.Base64.parse(encoded)));

console.log(encoded);
console.log(hash);

pm.variables.set('lightning-preimage', encoded);
pm.variables.set('lightning-payment-hash', hash);