Mural Mesh
Coordinate large-scale public murals with painters via gasless onchain collaboration and social login.
Privy social + sponsored tx· wallet UX
Section · Onchain
full primer →The primitive.
Painters sign in with Google through Privy — no seed phrase, no MetaMask popup — and their public mural collaboration actions post to Plasma from an embedded wallet topped up with free testnet XPL.
Why this primitivePrivy sponsored transactions ease multi-party approval without gas costs.
Kernel
Privy embedded wallet bootstrapped with PRIVY_APP_ID — Google sign-in creates an EOA on Plasma Testnet; users top up XPL from openfaucet.org
Drives the UI as
a one-click 'Sign in with Google' that drops the user straight into the app with an onchain identity on Plasma
Required keys.
METAMASK_PRIVATE_KEY
Exported from MetaMask. Fund on Plasma Testnet via openfaucet.org (free XPL).
open ↗PLASMA_RPC_URL
Plasma Testnet HTTPS RPC. Defaults to https://testnet-rpc.plasma.to; use a partner RPC for hackathon load.
open ↗Add these in your Lovable project under Settings → Secrets before pasting the prompt below. Plasmascan verification needs no API key.
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 "Mural Mesh" in ONE Lovable message. Single-page demo.
CONCEPT
Coordinate large-scale public murals with painters via gasless onchain collaboration and social login.
Discipline: Visual Art (public mural collaboration).
Onchain primitive: Privy social + sponsored tx. Why this primitive: Privy sponsored transactions ease multi-party approval 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 Plasma Testnet, verified on Plasmascan.
- Privy is the auth layer (Google login, embedded wallet). Users pay their own gas in XPL.
- 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).
- Target chain is **Plasma Testnet** (chainId 9746, native token XPL, ~1s blocks,
full EVM). RPC: https://testnet-rpc.plasma.to. Explorer: https://testnet.plasmascan.to.
Faucet: https://openfaucet.org/.
- Define the chain inline for viem (Privy accepts any viem chain, no built-in export needed):
const plasmaTestnet = {
id: 9746, name: 'Plasma Testnet',
nativeCurrency: { name: 'XPL', symbol: 'XPL', decimals: 18 },
rpcUrls: { default: { http: [import.meta.env.VITE_PLASMA_RPC_URL || 'https://testnet-rpc.plasma.to'] } },
blockExplorers: { default: { name: 'Plasmascan', url: 'https://testnet.plasmascan.to' } },
} as const;
- SSR-safe Privy mount is mandatory. Never import @privy-io/react-auth at
module scope of a route file — it crashes SSR. Use
lazy(() => import('./privy-client-entry')) inside <ClientOnly> + <Suspense>,
and put <PrivyProvider> only inside privy-client-entry.tsx.
- PrivyProvider config — pass the plasmaTestnet chain via supportedChains and
defaultChain so the embedded wallet lands on the right network:
<PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{ loginMethods:['google','email'],
supportedChains:[plasmaTestnet], defaultChain: plasmaTestnet,
embeddedWallets:{ ethereum:{ createOnLogin:'users-without-wallets' } },
appearance:{ theme:'dark' } }}>
- Read the embedded wallet from useWallets, not user.wallet:
const embedded = wallets.find(w => w.walletClientType === 'privy');
- Every send goes through Privy `useSendTransaction` with `address` and
`chainId: 9746`. Do NOT pass `sponsor: true` — Privy's native gas sponsorship
does not cover Plasma; users pay their own XPL. Wrap the call in a 45s
Promise.race timeout that tells the user to top up XPL if their balance is 0:
await Promise.race([
sendTransaction(
{ to, data, chainId: 9746 },
{ address: embedded.address }
),
new Promise((_, r) => setTimeout(() => r(new Error(
"Plasma tx timed out. Check the embedded wallet has XPL from https://openfaucet.org/"
)), 45_000)),
]);
- Preflight: before calling sendTransaction, read the wallet's XPL balance via
a viem publicClient({ chain: plasmaTestnet, transport: http() }). If it's 0,
render a toast + inline banner with a copy-address button and a link to
https://openfaucet.org/ so the user can drip XPL to themselves.
- Do NOT pass uiOptions:{ showWalletUIs:false } — it aborts with
"signal is aborted without reason". The approval sheet is fine.
- Do NOT add ZeroDev / SmartWalletsProvider / any paymaster URL. Plasma
Testnet uses simple EOA transactions.
- Hardhat lives in /contracts (kept outside the Vite bundle). Install
`@nomicfoundation/hardhat-toolbox` and `@nomicfoundation/hardhat-verify@latest`.
- hardhat.config.cjs — Plasma Testnet network + Plasmascan (Etherscan-compatible) verify:
require("@nomicfoundation/hardhat-toolbox");
require("@nomicfoundation/hardhat-verify");
module.exports = {
solidity: { version: "0.8.24", settings: { optimizer: { enabled: true, runs: 200 } } },
networks: { plasmaTestnet: {
url: process.env.PLASMA_RPC_URL || "https://testnet-rpc.plasma.to",
accounts: [process.env.METAMASK_PRIVATE_KEY.startsWith("0x")
? process.env.METAMASK_PRIVATE_KEY : "0x" + process.env.METAMASK_PRIVATE_KEY],
chainId: 9746,
} },
etherscan: {
apiKey: { plasmaTestnet: process.env.PLASMASCAN_API_KEY || "empty" },
customChains: [{
network: "plasmaTestnet",
chainId: 9746,
urls: { apiURL: "https://testnet.plasmascan.to/api",
browserURL: "https://testnet.plasmascan.to/" },
}],
},
sourcify: { enabled: false },
};
- Deploy: `npx hardhat run scripts/deploy.cjs --network plasmaTestnet`.
- Verify (right after deploy, no constructor args for these contracts):
`npx hardhat verify --network plasmaTestnet <address>`
Source becomes readable at `https://testnet.plasmascan.to/address/<address>#code`.
- Frontend reads via viem: `createPublicClient({ chain: plasmaTestnet,
transport: http(import.meta.env.VITE_PLASMA_RPC_URL) })`. Expose the RPC to
the client by also setting VITE_PLASMA_RPC_URL to the same value.
- Write the deployed address to `src/data/contract.json` so the UI links to
`https://testnet.plasmascan.to/address/<address>`.
CONTRACT (contracts/MuralMesh.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title SocialLogMuralMesh
/// @notice Coordinate large-scale public murals with painters via gasless onchain collaboration and social login.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract SocialLogMuralMesh {
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 Plasma Testnet.
2. If wallet XPL balance is 0, show the openfaucet.org top-up banner with copy-address.
3. Every public mural collaboration action the user performs is sent as a Plasma Testnet tx (`log(payload)`) from their Privy embedded wallet and displayed with a Plasmascan link. Users pay their own XPL gas.
4. 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 Plasma Testnet deployer key. Fund it (free XPL): https://openfaucet.org/ or https://faucet.quicknode.com/plasma
- PLASMA_RPC_URL Plasma Testnet HTTPS endpoint. Default: https://testnet-rpc.plasma.to (public). For hackathon load, use a partner RPC (see https://docs.plasma.org/docs/plasma-chain/tools/rpc-providers).
- PRIVY_APP_ID Google sign-in + embedded wallet. 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
Optional:
- PLASMASCAN_API_KEY Not required. Plasmascan's Etherscan-compatible API accepts any string; pass "empty".
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
$1B
public mural funding
SAM
$300M
collaborative mural initiatives
SOM
$18M
gasless onchain mural participants
Indicative figures for hackathon pitches — refine with your own research before raising.
Adjacent entries.
collaborative painting
Canvas Collaborate
Enable painters to co-create artworks with seamless onchain identity and gasless contributions.
illustrator communityIllustrator Guild
Create a hosted network for illustrators to share, sell, and verify work with easy login and zero gas fees.
generative artGenerative Canvas
Let generative artists deploy and monetize code-driven art with instant gasless onboarding and transactions.
art provenance trackingGallery Ledger
Provide gallerists with gasless, onchain tools to prove artwork provenance and authenticity effortlessly.