BetBat

A social prediction market for friend groups: create markets on questions your group cares about, place wagers in shared in-app coins, and let the group resolve outcomes by majority vote.

Built for UCLA CS 130 — Software Engineering, Spring 2026 (Team 11).

Tech stack

• Web app: Next.js 16 (App Router), React 19, TypeScript, Tailwind CSS 4
• Auth + database: Firebase (Authentication + Firestore)
• Server logic: Next.js API routes using the Firebase Admin SDK
• Hosting: Vercel (auto-deploys from main, preview deploys per PR)
• Tests: Vitest (unit) + a Node integration test against the Firestore emulator
• CI: GitHub Actions — typecheck, lint, unit tests, and build on every PR

Repo layout

.
├── web/                    # Next.js app — almost all the code lives here
│   ├── src/                # App Router pages, API routes, lib, components
│   ├── tests/              # Integration tests (Node, not Vitest)
│   ├── README.md           # Dev setup, scripts, troubleshooting
│   └── .env.example        # Required environment variables, documented
├── firebase.json           # Firebase project + emulator config
├── firestore.rules         # Firestore security rules (deployed manually)
├── firestore.indexes.json  # Firestore composite indexes (deployed manually)
└── .github/
    ├── workflows/ci.yml    # Typecheck, lint, unit tests, build
    ├── ISSUE_TEMPLATE/     # Feature / bug / tech-debt
    └── pull_request_template.md

Getting started

For dev setup, scripts, and troubleshooting, see web/README.md.

Quick version:

git clone https://github.com/wimaan3/BetBat-CS130.git
cd BetBat-CS130/web
npm install
cp .env.example .env.local        # then fill in Firebase config
npm run dev

Design constraints

The non-negotiable rules from the design doc:

• All coin operations run inside Firestore atomic transactions. Bet placement, payouts, and refunds either succeed completely or roll back completely — coins are never created or destroyed outside a transaction.
• Markets, bets, votes, and transactions are server-side writes only. Client SDK writes are denied by firestore.rules; the Next.js API routes perform all coin-touching writes using the Admin SDK.
• Resolution requires a 2/3 supermajority within 48 hours. Otherwise the market enters a DISPUTED state and stakes are refunded.

Team

Team 11, CS 130 Spring 2026:

• Imaan Soltanalipour
• Arnav Jain
• Maanas Gantla
• Skylar Shi
• Dhruv Saran

Status

This is an in-progress class project, not a production service. Issues tracked in the GitHub repo's Issues tab. Milestones: W6 Presentation 1 (done) and W10 Final Demo + Report.