Lottery VRF SDK

This is an sdk, connect to the Lottery VRF program on Solana.

Draw

An user can draw a random number from the VRF. Each time he draws, a new random number PDA account is generated to store the random number, using ORAO VRF.

import { Keypair, PublicKey } from "@solana/web3.js";
import { LotteryDrawClient } from "../src";


export const getWallet = (
) => {
  return Keypair.fromSecretKey(
    Uint8Array.from(require(`/root/.config/solana/id.json`))
  );
};

async function main() {
  const keypair = getWallet();
  const client = new LotteryDrawClient(keypair);


  const txHash = await client.draw();
  console.log(`Transaction: ${txHash}`);
}

main();

User: GyPcdYe7JrM3W172JecLvS9xUEScjQWhARHyYqT9mj8J, draw round: 2
Transaction: fyZ5op2N5RrEE4U9sMmyzkmvRQdTYxu1hkwV3VVnzW67goxvWSoovzScFrg5Tew91aJ1AV53qD6naDZ4mgNFYUs

For each round user draw, a draw PDA account in the program is creataed to store the associated information

Get Draw

This function, get the draw information from the program. Then, it will wait for the VRF to be fulfilled and return the draw information, including the randomness data.

import { Keypair, PublicKey } from "@solana/web3.js";
import { LotteryDrawClient } from "../src";

async function main() {
  const client = new LotteryDrawClient();
  const draw = await client.getDraw(new PublicKey("GyPcdYe7JrM3W172JecLvS9xUEScjQWhARHyYqT9mj8J"), 2);

  console.log("Drawer: ", draw.drawer.toBase58());
  console.log("Round: ", draw.round);
  console.log("Randomness: ", draw.randomness);
  console.log("Randomness Account: ", draw.randomnessAccount.toBase58());

  // Get randomness data in biguint64LE format
  const randomness = Buffer.from(draw.randomness).readBigUInt64LE();
  console.log("Randomness in biguint64LE LE: ", randomness.toString());
}

main();

➜  orao-vrf-sdk git:(main) ✗ ts-node examples/getDraw.ts 
Drawer:  8ekXR9PUuUUwmupGFLw3xTo1BFeRdescCGdwqMpK2swg
Round:  <BN: 2>
Randomness:  Uint8Array(64) [
  191,   0, 106, 104, 237, 215, 175,  44,  47,  56, 242,
    6, 104, 156,  42,  99, 136, 251, 222,  21,  41, 141,
   12,  27, 223, 126, 235, 114, 148,  49,  97, 140, 100,
  138, 221,  50,  30,  79, 253,  35,  86, 153, 233, 180,
  240,  17,  66,  99,   3, 182, 206, 202, 149,  17, 115,
  114, 151, 114, 200,  99,  15,   1,  77,   9
]
Randomness Account:  8REuCAFtP4FA7vsXE8Qtw2JuLrgozLNKWGXZUUDHCsPj
Randomness in biguint64LE LE:  3220029673252192447