Whisper Pay

About this project

Whisper Pay is an AI-powered bill splitting and private payment link service built on Starknet. Users photograph a receipt, and Claude reads the items, splits the cost among participants, and generates individual private payment links. Transactions are settled in STRK through the STRK20 privacy pool, keeping amounts, payers, and recipient identities completely off the public ledger without storing uploaded receipt data.

Whisper Pay is a zero-knowledge, AI-driven payment application engineered on Starknet mainnet to resolve the fundamental privacy flaw of peer-to-peer invoices. While standard public blockchain payment links expose wallet addresses, amounts, and interaction histories, Whisper Pay breaks this on-chain link by settling transactions through the STRK20 privacy pool. As a result, the payer, the receiver, and the underlying transfer amount stay completely off public block explorers.

In addition to on-chain privacy, the platform solves the real-world friction of manual bill splitting. Users capture a single photo of any printed receipt, which is parsed by Claude Haiku 4.5 using structured outputs across 44 global currencies. Organizers assign items in natural language, and the system dynamically calculates shares while pro-rating taxes and service charges. Each participant receives an individual /pay link locked to a fixed 10-minute STRK exchange rate. Built with zero-retention data policies, uploaded receipt images are processed strictly in-memory and never persisted to disks, databases, or logs.

Key features

• AI Receipt Parsing with Claude Haiku 4.5
• Support for 44 World Currencies with Structured Extraction
• Natural Language Item Assignment ("name - item, drink")
• Pro-Rated Tax and Service Charge Allocation
• Automated Largest-Remainder Division to Prevent Rounding Errors
• On-Chain Privacy Settlement via STRK20 Privacy Pool on Starknet
• Non-Custodial, Shareable One-Click Payment Links
• 10-Minute Locked-Rate Currency Quotes
• Strict Zero-Data Retention Architecture (Photos Never Stored)
• Automated Discrepancy Detection for Receipt Totals

Tech stack

Whisper Pay is built with Starknet, STRK20 Privacy Pool, Claude Haiku 4.5, Next.js, TypeScript, Vercel, Node.js.