Attested Compute

import {euint256, e, ebool, inco} from "@inco/lightning/src/Lib.sol";
import {DecryptionAttestation} from "@inco/lightning/src/lightning-parts/DecryptionAttester.types.sol";
import {asBool} from "@inco/lightning/src/shared/TypeUtils.sol";

contract TestAttestedCompute {
    euint256 hiddenCreditScore;

    constructor(address owner) payable {
        require(msg.value == inco.getFee(), "Fee not paid");
        hiddenCreditScore = e.asEuint256(800);
        e.allow(hiddenCreditScore, address(this));
        e.allow(hiddenCreditScore, owner);
    }

    function GetHandle() external returns (euint256) {
        return hiddenCreditScore;
    }

    function SubmitCreditCheck(
        DecryptionAttestation memory decryption,
        bytes[] memory signatures
    ) external {
        // Verify covalidator signatures over the attested result
        require(
            inco.incoVerifier().isValidDecryptionAttestation(decryption, signatures),
            "Invalid signature"
        );

        // Recompute the expected "creditScore >= 700" handle on-chain
        require(
            ebool.unwrap(e.ge(hiddenCreditScore, 700)) == decryption.handle,
            "Computed handle mismatch"
        );

        // Check that the decrypted boolean is true
        require(asBool(decryption.value) == true, "Credit check failed");

        // Credit check passed - proceed with loan approval
    }
}

import { Lightning } from '@inco/js/lite';
import { getViemChain, supportedChains, type HexString } from '@inco/js';
import { AttestedComputeSupportedOps } from '@inco/js/lite';
import { createWalletClient, custom } from 'viem'

const zap = await Lightning.latest('testnet', supportedChains.baseSepolia);

//Connect to Metamask or other wallet provider
const walletClient = createWalletClient({
  chain: getViemChain(supportedChains.baseSepolia),
  transport: custom(window.ethereum!)
})

// Retrieve the hiddenCreditScore handle from the contract by calling GetHandle(), e.g. using viem
const hiddenCreditScore = '0x<handle>' as HexString;

// isGreaterOrEqual = hiddenCreditScore >= 700
const isGreaterOrEqual = await zap.attestedCompute(
  walletClient,
  hiddenCreditScore,
  AttestedComputeSupportedOps.Ge,
  700n,
);

const creditScoreSufficient = isGreaterOrEqual.plaintext.value; // always boolean

ebool creditScoreSufficient = e.ge(hiddenCreditScore, 700);