Privy Scoreboard
Display and update player rankings with gas-free wallet sign-in and transaction updates.
Privy social + sponsored tx· wallet UX
Section · Onchain
full primer →The primitive.
Game designers sign in with Google through Privy — no seed phrase, no MetaMask popup — and their competitive ranking actions are sent as sponsored transactions so they never see gas.
Why this primitivePrivy social wallet plus sponsored tx keeps leaderboards updated without gas costs.
Kernel
Privy embedded wallet bootstrapped with PRIVY_APP_ID — Google sign-in plus sponsored Avalanche Fuji 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.
METAMASK_PRIVATE_KEY
Exported from MetaMask. Fund on Avalanche Fuji via the Avalanche Fuji faucet.
open ↗AVALANCHE_FUJI_RPC_URL
Alchemy Avalanche Fuji HTTPS endpoint (or https://api.avax-test.network/ext/bc/C/rpc).
open ↗ETHERSCAN_API_KEY
Single Etherscan v2 key — covers Snowtrace (chainId 43113) 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 "Privy Scoreboard" in ONE Lovable message. Single-page demo.
CONCEPT
Display and update player rankings with gas-free wallet sign-in and transaction updates.
Discipline: Game Design & Interactive Media (competitive ranking).
Onchain primitive: Privy social + sponsored tx. Why this primitive: Privy social wallet plus sponsored tx keeps leaderboards updated without gas costs.
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 Avalanche Fuji (chainId 43113), verified on Snowtrace.
- 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:
// IMPORTANT: pass the real viem `avalancheFuji` Chain object — a { id, name } stub
// silently breaks Privy's chain transport (sponsored tx + smart-wallet client init).
import { avalancheFuji } from 'viem/chains';
<PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{ loginMethods:['google'], embeddedWallets:{ethereum:{createOnLogin:'users-without-wallets'}},
defaultChain: avalancheFuji, supportedChains: [avalancheFuji] }}>
- All txs via Privy `useSendTransaction` with `{ sponsor: true }` (zero-gas for the user).
- 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 — Avalanche Fuji + Etherscan v2 single-key:
require("@nomicfoundation/hardhat-ethers");
require("@nomicfoundation/hardhat-verify");
const pk = process.env.METAMASK_PRIVATE_KEY;
module.exports = {
solidity: { version: "0.8.24", settings: { optimizer: { enabled: true, runs: 200 } } },
networks: { avalancheFuji: {
url: process.env.AVALANCHE_FUJI_RPC_URL || "https://api.avax-test.network/ext/bc/C/rpc",
accounts: pk ? [pk.startsWith("0x") ? pk : "0x" + pk] : [],
chainId: 43113,
} },
etherscan: {
apiKey: process.env.ETHERSCAN_API_KEY, // single Etherscan v2 key covers Snowtrace
customChains: [{
network: "avalancheFuji", chainId: 43113,
urls: {
apiURL: "https://api.etherscan.io/v2/api?chainid=43113",
browserURL: "https://testnet.snowtrace.io",
},
}],
},
sourcify: { enabled: false },
};
- Deploy: `npx hardhat run scripts/deploy.cjs --network avalancheFuji`.
- Verify (run RIGHT AFTER deploy, no constructor args for these contracts):
`npx hardhat verify --network avalancheFuji <address>`
On success it prints "Successfully verified contract … on the block explorer"
and the source becomes readable at
`https://testnet.snowtrace.io/address/<address>#code`.
- Frontend reads: create a viem public client with the Avalanche Fuji RPC too —
`createPublicClient({ chain: avalancheFuji, transport: http(import.meta.env.VITE_AVALANCHE_FUJI_RPC_URL) })`
(import `avalancheFuji` from `viem/chains`).
Expose the RPC to the client by also setting VITE_AVALANCHE_FUJI_RPC_URL to the same value.
- Write the deployed address to `src/data/contract.json` so the UI links to
`https://testnet.snowtrace.io/address/<address>`.
CONTRACT (contracts/PrivyScoreboard.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title SocialLogPrivyScoreboard
/// @notice Display and update player rankings with gas-free wallet sign-in and transaction updates.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract SocialLogPrivyScoreboard {
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 Avalanche Fuji.
2. Every competitive ranking action the user performs is sent as a sponsored Avalanche Fuji tx (`log(payload)`) and displayed with a Snowtrace 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):
- METAMASK_PRIVATE_KEY Avalanche Fuji deployer key. Fund it: https://build.avax.network/console/primary-network/faucet
(alt: https://build.avax.network/console/primary-network/faucet)
- AVALANCHE_FUJI_RPC_URL Alchemy Avalanche Fuji HTTPS endpoint (https://avax-fuji.g.alchemy.com/v2/<key>)
OR the public default https://api.avax-test.network/ext/bc/C/rpc. Create a free app: https://dashboard.alchemy.com/
- ETHERSCAN_API_KEY Single Etherscan v2 key — verifies on Snowtrace (chainId 43113) with no extra key.
Get: https://etherscan.io/myapikey
- PRIVY_APP_ID Google sign-in + sponsored tx. Enable Avalanche Fuji (43113) in your Privy dashboard.
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
$4.5B
esports and leaderboard market
SAM
$850M
indie competitive platforms
SOM
$170M
gasless leaderboard update tools
Indicative figures for hackathon pitches — refine with your own research before raising.
Adjacent entries.
multiplayer coordination
Gasless Guilds
Seamlessly create and join guilds with gas-free onboarding and instant member transactions.
reward distributionSponsored Loot Drops
Distribute in-game rewards directly to players' wallets without any gas fees.
XR social spacesPrivy VR Lobby
Enter virtual lobbies with gas-free wallet login and seamless social interactions.
digital fashionOnchain Avatar Store
Buy and customize avatars with zero gas fees using embedded wallets and sponsored transactions.