Choreo NFT Vault
Securely store and share choreography as NFTs without users handling gas payments.
Privy social + sponsored tx· wallet UX
Section · Onchain
full primer →The primitive.
Choreographers sign in with Google through Privy — no seed phrase, no MetaMask popup — and their digital choreography ownership actions are sent as sponsored transactions so they never see gas.
Why this primitivePrivy wallet with Google sign-in and sponsored tx eases NFT minting experience.
Kernel
Privy embedded wallet bootstrapped with PRIVY_APP_ID — Google sign-in plus sponsored Arbitrum Sepolia transactions so users never see gas
Drives the UI as
a one-click 'Sign in with Google' that drops the user straight into the app with an onchain identity
Required keys.
ARBITRUM_SEPOLIA_RPC_URL
Alchemy Arbitrum Sepolia HTTPS endpoint (or https://sepolia-rollup.arbitrum.io/rpc).
open ↗ETHERSCAN_API_KEY
Single Etherscan v2 key — covers Arbiscan (chainId 421614) with no extra key.
open ↗Add these in your Lovable project under Settings → Secrets before pasting the prompt below.
Appendix · Mega-prompt
The build prompt.
budget · 1 message
Paste into a fresh Lovable project. Make sure all five secrets above are set first. read the build strategy →
Build "Choreo NFT Vault" in ONE Lovable message. Single-page demo.
CONCEPT
Securely store and share choreography as NFTs without users handling gas payments.
Discipline: Dance & Choreography (digital choreography ownership).
Onchain primitive: Privy social + sponsored tx. Why this primitive: Privy wallet with Google sign-in and sponsored tx eases NFT minting experience.
5-CREDIT BUDGET (HARD LIMIT):
- ONE single-page app. No router, no Lovable Cloud, no database, no auth flows beyond Privy drop-in.
- ONE Solidity contract, <=80 lines, deployed to Arbitrum Sepolia (chainId 421614), verified on Arbiscan.
- Privy is always the auth + sponsored-tx layer (Google login, embedded wallet).
- Pinata/IPFS only if the idea genuinely needs to store a file or metadata.
- At most ONE AI call per user action (use Lovable AI Gateway with LOVABLE_API_KEY if AI is part of the idea).
- Skip tests, skip CI, skip docs pages. Ship the demo, nothing else.
STACK
- React + Vite single page (the index route).
- Privy embedded wallet wraps `<App />` in src/main.tsx. `defaultChain` needs
`as never` because Privy's type is narrow:
<PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{ loginMethods:['google'],
embeddedWallets:{ethereum:{createOnLogin:'users-without-wallets'}},
defaultChain: { id: 421614, name:'Arbitrum Sepolia' } as never }}>
- All txs go through Privy sponsorship. BOTH flags are required:
const { sendTransaction } = useSendTransaction();
const { wallets } = useWallets();
const embedded = wallets.find(w => w.walletClientType === 'privy');
await sendTransaction(
{ to, data, chainId: 421614 },
{ sponsor: true, address: embedded.address }, // BOTH required
);
Without `address`, Privy can route through a non-embedded wallet and the
user sees "Add funds on Arbitrum Sepolia" even on testnet.
- Privy dashboard (one-time): enable Arbitrum Sepolia under Chains AND add a
Gas Sponsorship (Paymasters) policy for chainId 421614 — "Sponsor all
transactions" is fine for a hackathon demo. Code flags alone are not enough.
- Hardhat in /contracts (kept outside the Vite bundle). Install
`@nomicfoundation/hardhat-ethers` AND `@nomicfoundation/hardhat-verify` (>=2.x).
DO NOT install `@nomicfoundation/hardhat-toolbox` — it drags Hardhat 3 peers.
- hardhat.config.cjs — Arbitrum Sepolia + Etherscan v2 single-key:
require("@nomicfoundation/hardhat-ethers");
require("@nomicfoundation/hardhat-verify");
const pk = process.env.DEPLOYER_PRIVATE_KEY || process.env.METAMASK_PRIVATE_KEY;
module.exports = {
solidity: { version: "0.8.24", settings: { optimizer: { enabled: true, runs: 200 } } },
networks: { arbitrumSepolia: {
url: process.env.ARBITRUM_SEPOLIA_RPC_URL || "https://sepolia-rollup.arbitrum.io/rpc",
accounts: pk ? [pk.startsWith("0x") ? pk : "0x" + pk] : [],
chainId: 421614,
} },
etherscan: {
apiKey: process.env.ETHERSCAN_API_KEY, // single Etherscan v2 key covers Arbiscan
// MUST be a plain string, not { arbitrumSepolia: ... }
customChains: [{
network: "arbitrumSepolia", chainId: 421614,
urls: {
apiURL: "https://api.etherscan.io/v2/api?chainid=421614",
browserURL: "https://sepolia.arbiscan.io",
},
}],
},
sourcify: { enabled: false },
};
- scripts/deploy.cjs — deploy AND write src/data/contract.json so the UI wires
up with no manual paste:
const hre = require("hardhat");
const fs = require("fs"); const path = require("path");
async function main() {
const c = await hre.ethers.deployContract("ChoreoNFTVault");
await c.waitForDeployment();
const address = await c.getAddress();
const deployTx = c.deploymentTransaction().hash;
fs.mkdirSync(path.join(__dirname, "..", "src", "data"), { recursive: true });
fs.writeFileSync(
path.join(__dirname, "..", "src", "data", "contract.json"),
JSON.stringify({
address, deployTx, chainId: 421614, network: "arbitrumSepolia",
deployedAt: new Date().toISOString(),
explorer: `https://sepolia.arbiscan.io/address/${address}`,
}, null, 2) + "\n",
);
console.log("deployed", address);
}
main().catch(e => { console.error(e); process.exit(1); });
- Run order (single burst):
bunx hardhat compile
bunx hardhat run scripts/deploy.cjs --network arbitrumSepolia
bunx hardhat verify --network arbitrumSepolia <address>
On verify success it prints "Successfully verified contract … on the block
explorer" and the source is readable at
`https://sepolia.arbiscan.io/address/<address>#code`.
- Frontend reads: create a viem public client with the Arbitrum Sepolia RPC too —
`createPublicClient({ chain: arbitrumSepolia, transport: http(import.meta.env.VITE_ARBITRUM_SEPOLIA_RPC_URL) })`
(import `arbitrumSepolia` from `viem/chains`).
Expose the RPC to the client by also setting VITE_ARBITRUM_SEPOLIA_RPC_URL to the same value.
- The UI imports `src/data/contract.json` directly — no env var, no manual paste —
and links to `https://sepolia.arbiscan.io/address/<address>`.
CONTRACT (contracts/ChoreoNFTVault.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title SocialLogChoreoNFTVault
/// @notice Securely store and share choreography as NFTs without users handling gas payments.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract SocialLogChoreoNFTVault {
event Logged(address indexed author, string cid, uint256 at);
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
function log(string calldata cid) external {
emit Logged(msg.sender, cid, block.timestamp);
}
}
```
USER FLOW
1. Land on page -> 'Sign in with Google' (Privy) -> embedded wallet auto-provisioned on Arbitrum Sepolia.
2. Every digital choreography ownership action the user performs is sent as a sponsored Arbitrum Sepolia tx (`log(payload)`) and displayed with a Arbiscan link. No wallet popups.
3. Footer renders: "Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14"
REQUIRED SECRETS (Lovable -> Project Settings -> Secrets):
- DEPLOYER_PRIVATE_KEY Arbitrum Sepolia deployer key (alias accepted: METAMASK_PRIVATE_KEY).
Fund it: https://faucet.quicknode.com/arbitrum/sepolia
(alt: https://www.alchemy.com/faucets/arbitrum-sepolia)
- ARBITRUM_SEPOLIA_RPC_URL Alchemy Arbitrum Sepolia HTTPS endpoint (https://arb-sepolia.g.alchemy.com/v2/<key>)
OR the public default https://sepolia-rollup.arbitrum.io/rpc. Create a free app: https://dashboard.alchemy.com/
- ETHERSCAN_API_KEY Single Etherscan v2 key — verifies on Arbiscan (chainId 421614) with no extra key.
Get: https://etherscan.io/myapikey
- PRIVY_APP_ID Google sign-in + sponsored tx. In the Privy dashboard you MUST:
(1) enable Arbitrum Sepolia (421614) under Chains, AND
(2) add a Gas Sponsorship (Paymasters) policy for 421614
("Sponsor all transactions" is fine for a hackathon demo).
Code flags alone are NOT enough — both dashboard toggles are required.
Docs: https://docs.privy.io/llms-full.txt
- PINATA_JWT IPFS uploads (only if app pins media). Docs: https://docs.pinata.cloud/llms-full.txt
CREDIT (must appear in UI footer AND as NatSpec on every deployed contract):
Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
Market sizing.
TAM
$5B
global dance content monetization
SAM
$800M
dance NFT market segment
SOM
$50M
choreographers minting digital rights
Indicative figures for hackathon pitches — refine with your own research before raising.
Adjacent entries.
competitive choreography
Gasless Dance Battles
Enable dancers to join and sponsor dance battles without paying gas fees.
membership managementStudio Access Club
Create token-gated memberships for dance studios with seamless gas-free onboarding.
usage rightsMovement Royalty Tracker
Automatically track and reward choreographers when their moves get used commercially.
community decision-makingGas-Free Dance Voting
Host dance community polls and awards with zero gas cost for voters.