build strategy · onchain
Real onchain, five secrets, one build.
Every mega-prompt in this repo uses the same pattern, because it's the only pattern that lets a Lovable account ship a verifiable Linea Sepolia demo in one shot.
Why Linea Sepolia and not mainnet?
Linea Sepolia is a real Ethereum L2 testnet — the same EVM, the same wallets, LineaScan on the Etherscan Multichain UI — but funded by a free faucet. Every contract you deploy is publicly inspectable, gas is effectively zero, and your demo can't accidentally drain a user. Move to Linea mainnet after the hackathon by swapping the RPC and chainId (59144).
The recipe
recipe
# 1. In your Lovable project, add five secrets (Settings -> Secrets): METAMASK_PRIVATE_KEY=0x... ETHERSCAN_API_KEY=... # LineaScan is on Etherscan Multichain, same key PRIVY_APP_ID=... PINATA_JWT=eyJhbGciOi... LINEA_SEPOLIA_RPC_URL=https://linea-sepolia.g.alchemy.com/v2/... # 2. Fund the MetaMask account on Linea Sepolia: open https://www.hackquest.io/faucets/59141 # 3. Copy a mega-prompt from this repo into Lovable. One paste: # - scaffolds the React app # - writes the Solidity contract (with hackathon credit in NatSpec) # - deploys to Linea Sepolia and verifies on LineaScan # - wires Privy social login (users approve their own sub-cent gas) # - pins generated assets to IPFS via Pinata # - exposes the contract address + LineaScan link in the UI # 4. Open the live LineaScan link. Your demo is provably onchain.
1. The contract — credit baked in
Every Solidity file deployed from a Creative Blockchain prompt MUST carry the hackathon credit in NatSpec, so provenance lives onchain alongside the bytecode.
contracts/Provenance.sol
// contracts/Provenance.sol — every contract carries the hackathon credit in NatSpec
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title Provenance
/// @notice Built during the Creative AI & Quantum Hackathon
/// @notice organised by StreetKode Fam during Indian Krump Festival 14
contract Provenance {
event Logged(address indexed author, string cid, uint256 at);
function log(string calldata cid) external {
emit Logged(msg.sender, cid, block.timestamp);
}
}
2. Deploy + verify on LineaScan
scripts/deploy.ts
// scripts/deploy.ts — reads METAMASK_PRIVATE_KEY + ETHERSCAN_API_KEY from process.env
import { ethers, run } from "hardhat";
async function main() {
const F = await ethers.getContractFactory("Provenance");
const c = await F.deploy();
await c.waitForDeployment();
const addr = await c.getAddress();
console.log("deployed:", addr);
// verify on LineaScan (Etherscan Multichain — same API key works)
await run("verify:verify", { address: addr, constructorArguments: [] });
}
main();
3. Pin assets to IPFS via Pinata
src/lib/pinata.ts
// src/lib/pinata.ts — pin a Blob to IPFS via Pinata JWT
export async function pinToIPFS(file: Blob, name = "artifact") {
const fd = new FormData();
fd.append("file", file, name);
const r = await fetch("https://api.pinata.cloud/pinning/pinFileToIPFS", {
method: "POST",
headers: { Authorization: `Bearer ${process.env.PINATA_JWT}` },
body: fd,
});
const { IpfsHash } = await r.json();
return IpfsHash as string; // the CID
}
4. Sign in with Google via Privy
src/main.tsx
// src/main.tsx — Privy social login on Linea Sepolia
import { PrivyProvider } from "@privy-io/react-auth";
// chainId is passed per-call on sendTransaction; no defaultChain stub needed.
<PrivyProvider
appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{
loginMethods: ["google", "email"],
embeddedWallets: { ethereum: { createOnLogin: "users-without-wallets" } },
appearance: { theme: "dark" },
}}
>
<App />
</PrivyProvider>
Hackathon rules of thumb
- · One mega-prompt = one build message. Don't iterate the architecture, iterate the UI.
- · Always show the live LineaScan link in the UI — that's your proof.
- · Linea Sepolia gas is sub-cent; users approve each tx themselves, no paymaster needed.
- · Pin every user-generated asset to IPFS the moment it's created.
- · Add a "Built during the Creative AI & Quantum Hackathon — StreetKode Fam · Indian Krump Festival 14" line to your footer.