BumpWallet

Demo

About

The problem it solves ## The Problem Onchain payments are still far more complicated than everyday digital payments. Today, sending crypto usually requires users to: - Copy and paste long wallet addresses - Scan QR codes - Switch between multiple apps - Manually choose chains and tokens - Risk sending funds to the wrong address These steps introduce **friction, confusion, and irreversible mistakes**, especially for non-crypto users. Paying someone in crypto should be as simple as tapping a card — but today it isn’t. --- ## The Solution **Bump makes onchain payments feel like contactless payments.** Instead of copying addresses or scanning QR codes, users simply **tap phones using NFC to send crypto instantly**. Bump combines identity, payments, and merchant checkout into a single mobile app. --- ## What People Can Use It For ### 🤝 Peer-to-Peer Payments Send stablecoins to friends, roommates, freelancers, or sellers by simply **tapping phones**. Perfect for: - Splitting bills - Paying someone back instantly - Creator or freelancer payments - Informal commerce at events or hackathons --- ### 🛍️ Merchant Checkout (Phone-Based POS) Bump includes a **merchant mode**, turning any phone into a crypto checkout terminal. Merchants can: - Add items to a simple POS cart - Generate a payment request - Let customers tap to approve and pay - Instantly confirm payment - Keep a simple transaction history No hardware terminals or integrations required. --- ### 🪪 Human-Readable Payment Identity Users can claim a **`*.bump.eth` ENS identity** for payments. Instead of sending to a long wallet address like: 0xabc123...9f2 Users pay something recognizable like: alice.bump.eth This makes payments **more trustworthy and reduces mistakes**. --- ### 📒 Clear Payment History Bump keeps a readable record of payments and syncs them to a **Fileverse-backed ledger**, helping users: - Track payments and receipts - Review past transactions - Treat crypto payments like normal financial activity --- ## Why It’s Better Bump improves crypto payments by making them: - **Faster** — tap-to-pay instead of copy/paste - **Safer** — ENS identities reduce address mistakes - **More familiar** — uses the same “tap to pay” interaction people already understand - **All-in-one** — wallet, identity, payments, POS, and transaction history in a single app --- ## In Short **Bump turns crypto payments into a simple, real-world interaction: tap phones and pay.**

How it's made

Challenges we ran into ## Challenges I Ran Into ### NFC Tap-to-Pay Between Phones Implementing tap-to-pay required handling **Android NFC at a low level**, including reader mode for the payer and **Host Card Emulation (HCE)** for the merchant. **Solution** I built custom Android native modules and designed a simple **NFC protocol** with session IDs and structured payment payloads to ensure reliable tap interactions. ### Reliable Payment Confirmation Blockchain events alone can be unreliable due to **websocket failures or delayed receipts**. **Solution** I implemented **multiple confirmation layers**: - realtime event watchers - transaction receipt checks - transfer log validation - polling fallback This ensures payments are confirmed even if one mechanism fails. --- ### Preventing Replay Attacks in NFC Payments A simple NFC transfer could allow **replay attacks or unsigned payment requests**. **Solution** Payments use **EIP-712 signed authorizations** verified by an onchain contract with nonce and deadline checks, supporting both EOAs and ERC-1271 smart wallets.