How to automatically burn solana token occasionally?

Question

Is it possible to burn specific amount of solana token occasionally on some specific web hook event? For example: On a blog site when a new post is published on specific tag, then n amount of token will be burned. Also there should a max amount limit of token that can burn on a single day? How do I achieve this?

Answer 1

To burn tokens you can for use the burn function in js. Like this for example to burn 1 token every second:

Setup:

import { getKeypairFromFile } from "@solana-developers/helpers";
import { TOKEN_2022_PROGRAM_ID, burn, createAccount, createMint, mintTo } from "@solana/spl-token";
import { Connection, Keypair } from "@solana/web3.js";


let connection = new Connection("http://127.0.0.1:8899", "confirmed");

const keyPair = await getKeypairFromFile();

const mintkeyPair = Keypair.generate();

console.log(keyPair.publicKey.toString());
console.log(mintkeyPair.publicKey.toString());

let confirmOptions = {
    preflightCommitment: "confirmed",
    commitment: "confirmed",
};

const mint = await createMint(
    connection,
    keyPair,
    keyPair.publicKey,
    keyPair.publicKey,
    9,
    mintkeyPair,
    confirmOptions,
    TOKEN_2022_PROGRAM_ID,
    );

console.log("mint", mint);

const tokenAccount = await createAccount(
    connection, 
    keyPair, 
    mintkeyPair.publicKey, 
    keyPair.publicKey, 
    undefined, 
    confirmOptions, 
    TOKEN_2022_PROGRAM_ID);

const sig = await mintTo(
    connection,
    keyPair,
    mintkeyPair.publicKey,
    tokenAccount,
    keyPair.publicKey,
    5000000000,
    undefined,
    undefined,
    TOKEN_2022_PROGRAM_ID
);

console.log("sig", sig);

Burn one token every second:

var x = 5;
var interval = 1000;

for (var i = 0; i < x; i++) {
    setTimeout(async function () {
        const burnSig = await burn(
            connection,
            keyPair,
            tokenAccount,
            mintkeyPair.publicKey,
            keyPair.publicKey,
            1000000000,
            undefined,
            undefined,
            TOKEN_2022_PROGRAM_ID
            );
        
        console.log("burnSig", burnSig);
    }, i * interval)
}

You can then run this in vercel for example or trigger it via a cron job.

If you want to burn it every time another account changes you can use onAccountChange web socket connection for example like so:

    connection.onAccountChange(
        accountThatYouWantToListenTo,
        (updatedAccountInfo, context) =>
        yourBurnHere(),
        "confirmed"
    );

If you have your token authority in your program you can also use on chain automation using clock work: https://github.com/open-clockwork/clockwork

There are also RPC providers that offer webhook solutions. Helius for example: https://docs.helius.dev/webhooks-and-websockets/what-are-webhooks