USD Flash Wallet Integration

I need working code—ready by tomorrow—that lets a user perform a USD Flash transfer inside a blockchain-based wallet and instantly see the updated balance on screen. The flow is simple: the user triggers a USD Flash move, the backend processes it securely, the wallet balance refreshes in real time, and the temporary tokens remain visible for up to 180 days before they expire.

The solution has to run on a blockchain platform (the wallet already operates there) and must include solid error handling, strict transaction validation, and clean scalability hooks so future volume spikes or protocol tweaks won’t break anything. Please keep data integrity and security top of mind; I don’t want race conditions, double-spends, or orphaned balances creeping in.

Deliverables
• Backend logic (API or smart-contract layer) that carries out the USD Flash transfer and logs all states
• Real-time balance update wired to the existing UI (web3 or equivalent)
• Clear instructions to deploy, test, and roll back if needed

Acceptance criteria
• A test transfer completes with zero failed states and shows the new balance within one second
• After manual tampering attempts, balances remain consistent and the ledger verifiably intact
• A scripted test confirms token disappearance exactly at the 180-day mark

If you’ve built similar payment or cryptocurrency systems—or anything in Solidity, Web3.js, ethers.js, Node.js, or comparable stacks—your experience will accelerate this job. I’ll be online for quick feedback cycles, so we can hit tomorrow’s deadline together.