Bump

Bump is an Android app for sending and receiving crypto with a phone tap.

It brings together a wallet, a merchant checkout flow, human-readable ENS names, and simple payment records in one product. The goal is straightforward: make onchain payments feel closer to contactless payments people already understand.

What Bump Does

Bump is built around a few simple product ideas:

• Tap to pay instead of copying addresses or scanning codes
• Use an ENS name instead of a wallet string
• Let merchants create a quick checkout from the same app
• Keep a readable record of completed payments

In the app, a user can log in, get a wallet, claim a *.bump.eth name, receive money, pay another user, or run a merchant checkout flow. There is also an optional privacy flow for merchant payments backed by the BitGo service in this repo.

Main Product Flows

Wallet

• Sign in with email or Google
• Provision an embedded wallet and smart wallet
• View demo balances for USDC and USDT
• Send and receive payments from the app

Identity

• Claim a *.bump.eth name during onboarding
• Save payment preferences to ENS
• Use a name people can remember instead of a long address

Merchant Checkout

• Add items in a POS-style screen
• Create a payment request
• Let the customer tap and pay
• Track the payment through confirmation

Payment Records

• Sync completed transactions into a Fileverse-backed ledger
• Keep a simple, readable history of what was sent or received

Demo Flow

1. Open the app and sign in.
2. Let the wallet finish setting up.
3. Claim an ENS name.
4. Create a merchant checkout or open a receive flow.
5. Tap from the payer device to complete the payment.
6. Show the confirmed transaction and updated history.

Tech Snapshot

Layer	Stack
App	Expo 55, React Native 0.83, TypeScript
Auth and wallet	Privy
Network	Base Sepolia
Tokens	USDC, USDT
Identity	ENS
Records	Fileverse
Merchant privacy flow	BitGo sidecar service
Platform	Android only

Quick Start

Prerequisites

• Node.js 18+
• npm
• Android Studio with an emulator or Android device

Install

npm install

This repo already includes legacy-peer-deps=true in .npmrc for web3 dependency compatibility.

Configure Environment

cp .env.example .env

Fill in the values below:

Variable	Required	Purpose
EXPO_PUBLIC_PRIVY_APP_ID	Yes	Privy app id
EXPO_PUBLIC_PRIVY_CLIENT_ID	Yes	Privy client id
EXPO_PUBLIC_FILEVERSE_API_URL	Optional	Fileverse API base URL
EXPO_PUBLIC_FILEVERSE_API_KEY	Optional	Fileverse API key
EXPO_PUBLIC_BITGO_API_URL	Optional	BitGo merchant API base URL

If you deploy the BitGo backend to Railway, use the generated public service URL directly, for example:

EXPO_PUBLIC_BITGO_API_URL=https://your-bitgo-api.up.railway.app

Do not append /api/bitgo here. The app adds the API path itself.

Run

npm start

npm run android

If the Android project needs to be generated first:

npm run prebuild

Bump is built for Android. The repo still includes Expo ios and web scripts, but Android is the supported product target here.

Optional BitGo Service

The BitGo service is only needed for the merchant privacy flow.

cd services/bitgo-api
npm install
npm run dev

More setup details are in services/bitgo-api/README.md.

Project Structure

Path	Purpose
app/	App screens and routes
components/	Shared UI components
constants/	Theme values and app constants
lib/	Wallet, ENS, NFC, payment, and record logic
services/bitgo-api/	Optional merchant privacy backend
packages/contracts/	Contract workspace

Key Files

• app/_layout.tsx sets up the app shell and route stack.
• app/login.tsx handles sign-in.
• app/ens-onboarding.tsx handles ENS setup.
• app/receive.tsx and app/pay-nfc.tsx cover tap-based payment flows.
• app/pos-terminal.tsx provides the merchant POS flow.
• lib/fileverse/ledger.ts stores payment records in Fileverse.

Related Docs

• services/bitgo-api/README.md
• packages/contracts/README.md
• AGENTS.md