AnimMetaManager
Securely store and update animation metadata onchain to maintain provenance and rights data.
Sepolia smart contract· onchain logic
Section · Onchain
full primer →The primitive.
Metadata control gets a tiny Solidity contract deployed to Ethereum Sepolia; filmmakers see a 'verified onchain' badge with the live contract address and a one-tap Etherscan link.
Why this primitiveSepolia smart contracts ensure metadata integrity and public verification.
Kernel
a Solidity contract deployed to Optimism Sepolia via MetaMask private key, then verified on Optimism Etherscan (Etherscan v2)
Drives the UI as
a 'verified onchain' badge with the live contract address and a Optimism Etherscan link
Required keys.
OPTIMISM_SEPOLIA_RPC_URL
Alchemy Optimism Sepolia HTTPS endpoint (or https://sepolia.optimism.io).
open ↗ETHERSCAN_API_KEY
Single Etherscan v2 key — covers Optimism Etherscan (chainId 11155420) 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 "AnimMetaManager" in ONE Lovable message. Single-page demo.
CONCEPT
Securely store and update animation metadata onchain to maintain provenance and rights data.
Discipline: Filmmaking & Animation (metadata control).
Onchain primitive: Sepolia smart contract. Why this primitive: Sepolia smart contracts ensure metadata integrity and public verification.
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 Sepolia, verified on Etherscan.
- 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:
<PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
config={{ loginMethods:['google'], embeddedWallets:{createOnLogin:'users-without-wallets'},
defaultChain:{ id: 11155111, name:'Sepolia' } }}>
- All txs via Privy `useSendTransaction` with `{ sponsor: true }` (zero-gas for the user).
- Hardhat in /contracts (kept outside the Vite bundle). Install
`@nomicfoundation/hardhat-toolbox` AND `@nomicfoundation/hardhat-verify@latest`
(>=3.x — older versions still hit Etherscan v1 and fail with
"You are using a deprecated V1 endpoint, switch to Etherscan API V2").
- hardhat.config.cjs MUST use the Etherscan v2 single-key shape (NOT the per-network map):
require("@nomicfoundation/hardhat-toolbox");
require("@nomicfoundation/hardhat-verify");
module.exports = {
solidity: { version: "0.8.24", settings: { optimizer: { enabled: true, runs: 200 } } },
networks: { sepolia: {
url: process.env.SEPOLIA_RPC_URL, // Alchemy HTTPS endpoint, REQUIRED
accounts: [process.env.METAMASK_PRIVATE_KEY.startsWith("0x")
? process.env.METAMASK_PRIVATE_KEY : "0x" + process.env.METAMASK_PRIVATE_KEY],
chainId: 11155111,
} },
etherscan: { apiKey: process.env.ETHERSCAN_API_KEY }, // single string, NOT { sepolia: ... }
sourcify: { enabled: false }, // silences the v2.x prompt
};
- Deploy: `npx hardhat run scripts/deploy.cjs --network sepolia`.
- Verify (run RIGHT AFTER deploy, no constructor args for these contracts):
`npx hardhat verify --network sepolia <address>`
On success Etherscan returns "Successfully verified contract … on the block explorer"
and the source becomes readable at
`https://sepolia.etherscan.io/address/<address>#code`.
- Frontend reads: create a viem public client with the Alchemy URL too —
`createPublicClient({ chain: sepolia, transport: http(import.meta.env.VITE_SEPOLIA_RPC_URL) })`.
Expose SEPOLIA_RPC_URL to the client by also setting VITE_SEPOLIA_RPC_URL to the same value.
- Write the deployed address to `src/data/contract.json` so the UI links to
`https://sepolia.etherscan.io/address/<address>`.
CONTRACT (contracts/AnimMetaManager.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title AnimMetaManager
/// @notice Securely store and update animation metadata onchain to maintain provenance and rights data.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract AnimMetaManager {
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.
2. User performs a metadata control action; the app calls `log(payload)` on the contract via Privy sponsored tx and shows the Etherscan link as proof.
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 Sepolia deployer key. Fund it: https://cloud.google.com/application/web3/faucet/ethereum/sepolia
- SEPOLIA_RPC_URL Alchemy Sepolia HTTPS endpoint (https://eth-sepolia.g.alchemy.com/v2/<key>). Create a free app at https://dashboard.alchemy.com/ -> copy the HTTPS URL. Public RPCs throttle/fail under hackathon load — Alchemy is required.
- ETHERSCAN_API_KEY For `npx hardhat verify`. Get: https://etherscan.io/myapikey
- PRIVY_APP_ID Google sign-in + sponsored tx. 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
$400B
animation asset management
SAM
$700M
metadata platforms for creatives
SOM
$10M
onchain metadata tools
Indicative figures for hackathon pitches — refine with your own research before raising.
Adjacent entries.
frame provenance
FrameChain Ledger
Verify animation frames' originality and authorship on an immutable blockchain ledger.
script rights trackingScriptMint
Track and transfer screenplay rights securely through blockchain for transparent ownership history.
crowd animation fundingAnimStake Voting
Enable decentralized community voting to fund independent animations using secure onchain ballots.
motion asset NFTsMotionNFT Vault
Mint and trade unique motion design assets as NFTs with verifiable ownership and licensing.