about_axiomREPL.md

Open this in Axiom REPL →

circuit.js

//
//                 _                 _____  ______ _____  _      
//     /\         (_)               |  __ \|  ____|  __ \| |     
//    /  \   __  ___  ___  _ __ ___ | |__) | |__  | |__) | |     
//   / /\ \  \ \/ / |/ _ \| '_ ` _ \|  _  /|  __| |  ___/| |     
//  / ____ \  >  <| | (_) | | | | | | | \ \| |____| |    | |____ 
// /_/    \_\/_/\_\_|\___/|_| |_| |_|_|  \_\______|_|    |______|
//                                                              
// Docs: https://docs.axiom.xyz/sdk/typescript-sdk/axiom-circuit/

// Example Axiom REPL circuit to prove the average balance of an account over a fixed time period
// Number of samples to take. Note that this must be a constant value and NOT an input because the size of 
// the circuit must be known at compile time.
const samples = 8;

// Number of blocks between each sample.
const spacing = 900;

// Validate that the block number is greater than the number of samples times the spacing
if (inputs.blockNumber.value() <= (samples * spacing)) {
  throw new Error("Block number must be greater than the number of samples times the spacing");
}

// Perform the block number validation in the circuit as well
checkLessThan(mul(samples, spacing), inputs.blockNumber);

// Get account balance at the sample block numbers
let sampledAccounts = new Array(samples);
for (let i = 0; i < samples; i++) {
  const sampleBlockNumber: CircuitValue = sub(inputs.blockNumber, mul(spacing, i));
  const account = getAccount(sampleBlockNumber, inputs.address);
  sampledAccounts[i] = account;
}

// Accumulate all of the balances to `total`
let total = constant(0);
for (const account of sampledAccounts) {
  const balance: CircuitValue256 = await account.balance();
  total = add(total, balance.toCircuitValue());
}

// Divide the total amount by the number of samples to get the average value
const average = div(total, samples);

// We call `addToCallback` on all values that we would like to be passed to our contract after the circuit has
// been proven in ZK. The values can then be handled by our contract once the prover calls the callback function.
addToCallback(inputs.blockNumber);
addToCallback(inputs.address);
addToCallback(average);

inputs.json

{
    "blockNumber": 5000000,
    "address": "0xEaa455e4291742eC362Bc21a8C46E5F2b5ed4701"
}