TransitionChain Vault

Required keys.

Add these in your Lovable project under Settings → Secrets before pasting the prompt below.

Paste into a fresh Lovable project. Make sure the secrets above are set first. read the build strategy →

Build "TransitionChain Vault" in ONE Lovable message. Single-page demo.

CONCEPT
Store reusable video transition presets on IPFS to ensure permanent, shareable effects.
Discipline: Videography & Film (transition effects).
Onchain primitive: IPFS via Pinata. Why this primitive: Pinata pins transition data immutably, facilitating collaboration and versioning.

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 Shasta, verified on Tronscan.
- Privy is always the auth + signing layer (Google login, embedded Tron wallet, raw-hash sign). It does NOT sponsor gas.
- Transactions are built and broadcast via TronGrid Shasta (`/api/public/tron-build` + `/api/public/tron-sponsor`). Shasta’s free daily bandwidth covers gas for small tx like `log(string)` — no TRX is paid, no relayer sponsors it.
- 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).
- 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.
- Privy Tron support is TIER-2 raw-sign (docs: https://docs.privy.io/recipes/tron/transatron).
  PrivyProvider config:
    <PrivyProvider appId={import.meta.env.VITE_PRIVY_APP_ID}
      config={{ loginMethods:['google','email'],
                appearance:{ theme:'dark' } }}>
- Read (or auto-create) the embedded Tron wallet via
  `useCreateWallet({ chainType:'tron' })` and read the base58 address off
  the resulting wallet. Addresses are base58 (T-prefixed), NOT hex.
- SHASTA RPC RULE (critical): use TronGrid Shasta
  `https://api.shasta.trongrid.io` for BOTH transaction build AND
  broadcast, with header `TRON-PRO-API-KEY: process.env.TRONGRID_API_KEY`
  on every request. Do NOT hit `api.transatron.io` on Shasta — that
  endpoint is mainnet-only and returns `Smart contract is not exist.` for
  a live Shasta contract, which surfaces in the UI as `build failed
  (500)`. Transatron sponsorship is a mainnet swap; on Shasta a fresh
  account’s free daily bandwidth (~600) covers a small `log(string)`
  event without any sponsor.
- Two server routes, both under `src/routes/api/public/` (auth-bypass
  prefix), both constructing TronWeb the same way:
    import { TronWeb, providers } from 'tronweb';
    const SHASTA_RPC = 'https://api.shasta.trongrid.io';
    const headers = { 'TRON-PRO-API-KEY': process.env.TRONGRID_API_KEY };
    const tronWeb = new TronWeb({
      fullNode:     new providers.HttpProvider(SHASTA_RPC, 60_000, '', '', headers),
      solidityNode: new providers.HttpProvider(SHASTA_RPC, 60_000, '', '', headers),
      eventServer:  new providers.HttpProvider(SHASTA_RPC, 60_000, '', '', headers),
    });
    1. POST /api/public/tron-build → builds the unsigned tx with
       `triggerSmartContract(contractHex, 'log(string)', { feeLimit }, [...], ownerHex)`
       and returns `{ transaction, txId: transaction.txID }`.
    2. POST /api/public/tron-sponsor → attaches the recovery byte to
       the user’s signature (try `1b`, fall back to `1c` by checking
       `tronWeb.trx.ecRecover(signed) === walletAddress`) and broadcasts
       via `tronWeb.fullNode.request('wallet/broadcasttransaction',
       signed, 'post')`. Same TronGrid host — no Transatron on Shasta.
- Client signs the `txID` with Privy’s raw signer (not sendTransaction):
    import { useSignRawHash } from '@privy-io/react-auth/extended-chains';
    const { signature } = await signRawHash({
      address: tronAddress, chainType: 'tron',
      hash: (txId.startsWith('0x') ? txId : '0x' + txId) as `0x${string}`,
    });
    // POST { walletAddress, signature, transaction } to /api/public/tron-sponsor
- Do NOT set `chainId` (Tron has no numeric EVM chainId). Do NOT reuse
  viem’s `sepolia`/`mainnet` chain objects. Do NOT add ZeroDev /
  SmartWalletsProvider / a paymaster URL — EVM-only concepts.
- TronBox in /contracts (kept outside the Vite bundle). Install
  `tronbox` (>=4.x). Solidity 0.8.x only (TVM caps at ~0.8.23 — do NOT
  bump above 0.8.20 for safety).
- tronbox-config.js:
    module.exports = {
      networks: {
        shasta: {
          privateKey: process.env.TRON_PRIVATE_KEY,
          userFeePercentage: 100,
          feeLimit: 1000_000_000,
          fullHost: 'https://api.shasta.trongrid.io',
          network_id: '2',
          headers: { 'TRON-PRO-API-KEY': process.env.TRONGRID_API_KEY },
        },
      },
      compilers: { solc: { version: '0.8.20' } },
    };
- Deploy: `tronbox migrate --network shasta`.
- Verify: upload source at `https://shasta.tronscan.org/#/contracts/verify`
  (needs a reCAPTCHA — cannot be scripted). If TRONSCAN_API_KEY is set
  you may POST multipart to `https://apilist.tronscanapi.com/api/solidity/verify`.
- Write the deployed base58 address to `src/data/contract.json` so the UI
  links to `https://shasta.tronscan.org/#/contract/<address>`.

CONTRACT (contracts/TransitionChainVault.sol):
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/// @title CIDLogTransitionChainVault
/// @notice Store reusable video transition presets on IPFS to ensure permanent, shareable effects.
/// @notice Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
contract CIDLogTransitionChainVault {
    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. On submit, pin the transition effects artefact to Pinata, then call `log(cid)` on the contract via Privy raw-hash sign + TronGrid broadcast (Shasta free bandwidth, no sponsor). Render the CID, IPFS gateway preview, and Tronscan tx 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):
- TRON_PRIVATE_KEY         Shasta deployer key (64 hex, no 0x prefix). Fund it: https://shasta.tronex.io/join/getJoinPage
- TRONGRID_API_KEY         TronGrid full-node key. Free: https://www.trongrid.io/dashboard/apikeys. Sent as `TRON-PRO-API-KEY` header on EVERY Shasta call — both build and broadcast.
- TRONSCAN_API_KEY         Optional — only for automated Tronscan source verification. Manual upload works without it: https://tronscan.org/#/myProfile/apiKeys
- PRIVY_APP_ID             Google sign-in + embedded Tron wallet via Privy. Docs: https://docs.privy.io/recipes/tron/transatron
- TRANSATRON_SPENDER_KEY   MAINNET ONLY — unused on Shasta. Reserve for a future mainnet swap; keep server-side. Docs: https://docs.transatron.io/
- 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.

Indicative figures for hackathon pitches — refine with your own research before raising.