Sponsored Loot Drops
Distribute in-game rewards directly to players' wallets without any gas fees.
The primitive.
Game designers sign in with Google through Privy — no seed phrase, no MetaMask popup — and an embedded wallet signs every reward distribution action on 0G Galileo (users top up with free testnet OG from the 0G faucet).
Why this primitiveSponsored transactions allow frictionless token drops without user gas payments, improving user experience.
Required keys.
Add these three in your Lovable project under Settings → Secrets before pasting the prompt below. 0G's public RPC (https://evmrpc-testnet.0g.ai) is hardcoded — no RPC key needed.
The build prompt.
Paste into a fresh Lovable project. Make sure all five secrets above are set first. read the build strategy →
Build "Sponsored Loot Drops" in ONE Lovable message. Single-page demo.
CONCEPT
Distribute in-game rewards directly to players' wallets without any gas fees.
Discipline: Game Design & Interactive Media (reward distribution).
Onchain primitive: Privy social + sponsored tx. Why this primitive: Sponsored transactions allow frictionless token drops without user gas payments, improving user 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 0G Galileo testnet, source uploaded to Chainscan-Galileo.
- Privy is always the auth + embedded-wallet layer (Google login, chainId 16602). Privy does NOT sponsor gas on 0G — the user signs every tx and pays in OG (top up from https://faucet.0g.ai, 0.1 OG/day).
- 0G Storage SDK (`@0glabs/0g-ts-sdk`) only if the idea genuinely needs to store a file.
- At most ONE AI call per user action via Lovable AI Gateway (LOVABLE_API_KEY, auto-provisioned) from a server route / server function. Default model: google/gemini-3-flash-preview.
- Skip tests, skip CI, skip docs pages. Ship the demo, nothing else.
0G GALILEO TESTNET (hardcode — no RPC secret needed):
chainId: 16602 (0x40DA)
name: "0G Galileo Testnet"
nativeCurrency: { name: "0G", symbol: "OG", decimals: 18 }
rpcUrl: "https://evmrpc-testnet.0g.ai"
explorer: "https://chainscan-galileo.0g.ai"
storageExplorer: "https://storagescan-galileo.0g.ai"
storageIndexer: "https://indexer-storage-testnet-turbo.0g.ai"
STACK
- React + Vite single page (the index route).
- Privy embedded wallet wraps `<App />` in src/main.tsx:
<PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{ loginMethods:['google'], embeddedWallets:{createOnLogin:'users-without-wallets'},
defaultChain:{ id: 16602, name:'0G Galileo Testnet',
nativeCurrency:{ name:'0G', symbol:'OG', decimals:18 },
rpcUrls:{ default:{ http:['https://evmrpc-testnet.0g.ai'] } },
blockExplorers:{ default:{ name:'Chainscan', url:'https://chainscan-galileo.0g.ai' } } } }}>
- All txs via Privy `useSendTransaction` with `chainId: 16602`. Privy does NOT sponsor gas on 0G — the user signs and pays in OG from their embedded wallet. Surface a "Top up at https://faucet.0g.ai" hint when balance is 0.
- Hardhat in /contracts (kept outside the Vite bundle). Install `@nomicfoundation/hardhat-toolbox`.
- hardhat.config.cjs (no Etherscan plugin — 0G uses Chainscan's web UI for verification):
require("@nomicfoundation/hardhat-toolbox");
module.exports = {
solidity: { version: "0.8.28", settings: { optimizer: { enabled: false }, evmVersion: "paris" } },
networks: { galileo: {
url: "https://evmrpc-testnet.0g.ai",
accounts: [process.env.METAMASK_PRIVATE_KEY.startsWith("0x")
? process.env.METAMASK_PRIVATE_KEY : "0x" + process.env.METAMASK_PRIVATE_KEY],
chainId: 16602,
} },
};
- Deploy: `npx hardhat run scripts/deploy.cjs --network galileo`.
- VERIFY on 0G Chainscan (manual, web UI — there is no Etherscan-compatible API):
1. Open `https://chainscan-galileo.0g.ai/address/<deployedAddress>` and click "Contract" -> "Verify and Publish".
2. Compiler: solc 0.8.28, optimization OFF, evmVersion: paris. These exact settings are required for Chainscan-Galileo to match bytecode — do not deviate.
3. Paste the flattened source (`npx hardhat flatten contracts/X.sol > flat.sol`, strip duplicate SPDX/pragma lines).
4. Submit. On success the source becomes readable at `https://chainscan-galileo.0g.ai/address/<address>#code`.
If verification fails with a bytecode mismatch, the cause is almost always optimizer ON or a different evmVersion — redeploy with the settings above rather than fighting the verifier.
- Frontend reads use viem with the hardcoded 0G RPC:
import { defineChain, createPublicClient, http } from 'viem';
export const galileo = defineChain({
id: 16602, name: '0G Galileo Testnet',
nativeCurrency: { name: '0G', symbol: 'OG', decimals: 18 },
rpcUrls: { default: { http: ['https://evmrpc-testnet.0g.ai'] } },
blockExplorers: { default: { name: 'Chainscan', url: 'https://chainscan-galileo.0g.ai' } },
});
const client = createPublicClient({ chain: galileo, transport: http() });
- Write the deployed address to `src/data/contract.json` so the UI links to
`https://chainscan-galileo.0g.ai/address/<address>`.
CONTRACT (contracts/SponsoredLootDrops.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title SocialLogSponsoredLootDrops
/// @notice Distribute in-game rewards directly to players' wallets without any gas fees.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract SocialLogSponsoredLootDrops {
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 0G Galileo (chainId 16602).
2. Every reward distribution action the user performs is sent as a 0G Galileo tx (`log(payload)`) from the Privy embedded wallet (user signs, pays gas in OG) and displayed with a Chainscan-Galileo link.
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):
- METAMASK_PRIVATE_KEY 0G Galileo deployer key. Fund it: https://faucet.0g.ai (0.1 OG/day) or https://hub.0g.ai/faucet?network=testnet
- PRIVY_APP_ID Google sign-in + embedded wallet on 0G Galileo (user signs their own tx). Docs: https://docs.privy.io/llms-full.txt
AI calls (if the idea uses AI) go through Lovable AI Gateway via the auto-provisioned LOVABLE_API_KEY — no secret to add.
Base URL: https://ai.gateway.lovable.dev/v1 Header: Lovable-API-Key: $LOVABLE_API_KEY
Default model: google/gemini-3-flash-preview. Call from a server route / server function only; never expose the key client-side.
No SEPOLIA_RPC_URL, no ETHERSCAN_API_KEY, no PINATA_JWT, no AISA_API_KEY. 0G's public RPC is hardcoded
(https://evmrpc-testnet.0g.ai), verification happens on Chainscan-Galileo's web UI,
and blobs go through the 0G Storage SDK signed by the deployer key.
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.
Indicative figures for hackathon pitches — refine with your own research before raising.