Hello from the bounty.gg team 👋

We feel it's important to stay transparent, which is why we're making the official provably fair implementation used on the bounty.gg servers public here

Usage

const pf = require("@bountygg/provably-fair");

async function aQuickTestRun() {
    const ticketCount = 10000; // lets pretend there are 10k tickets in the jackpot round

    // generate a random string
    const serverSeed = pf.getRandomBytes();
    // get a random string from a third party (here random.org)
    const thirdPartySalt = (await pf.getThirdPartySalt()).value;
    // concat both seeds
    const fullSeed = `${serverSeed}-${thirdPartySeed}`;
    // get winning percentage based on both the locally-generated `serverSeed` and the third-party `thirdPartySeed`
    // see https://chancejs.com/usage/seed.html for an example implementation
    const winningPercentage = pf.getPseudoRandomPercentage(fullSeed);

    // we're done! now we're able to get the winning ticket
    const winningTicket = pf.getWinningTicket(winningPercentage, ticketCount);

    console.table({
        ticketCount,
        serverSeed,
        thirdPartySeed,
        fullSeed,
        winningPercentage: winningPercentage.toNumber(),
        winningTicket
    });
}

aQuickTestRun();

Run the example above with

RANDOM_ORG_API_KEY=\<your random.org api key\> node index.js

You can get a free api key for the random.org gRPC api from api.random.org