LunchVote

Ranked-choice (instant-runoff) lunch decisions for your team. Built with Next.js 15, Turso, Drizzle ORM, Auth.js v5, and Tailwind CSS.

Local Setup

1. Install dependencies

pnpm install

2. Set up environment variables

cp .env.example .env.local

Fill in the values (see comments in .env.example).

3. Set up Turso

1. Install the Turso CLI: https://docs.turso.tech/installation
2. Sign up / log in: turso auth login
3. Create a database: turso db create lunch-vote
4. Get credentials:

   turso db show lunch-vote --url    # → TURSO_DATABASE_URL
   turso db tokens create lunch-vote # → TURSO_AUTH_TOKEN

5. Add to .env.local.

4. Set up Google OAuth

1. Go to https://console.cloud.google.com/apis/credentials
2. Create an OAuth 2.0 Client ID (Web application)
3. Authorized redirect URI: http://localhost:3000/api/auth/callback/google
4. Copy the client ID and secret to .env.local as AUTH_GOOGLE_ID and AUTH_GOOGLE_SECRET
5. Set ALLOWED_EMAIL_DOMAIN to your Google Workspace domain (e.g. example.com)

5. Run migrations

pnpm db:generate   # generate migration files from schema
pnpm db:migrate    # apply migrations to Turso

6. Seed sample data

pnpm db:seed

This inserts 8 sample places (the Rome team's favorites from the design mockup).

7. Start dev server

pnpm dev

Open http://localhost:3000.

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Environment Variables

Variable	Required	Description
TURSO_DATABASE_URL	✅	Turso database URL (libsql://...)
TURSO_AUTH_TOKEN	✅	Turso auth token
AUTH_SECRET	✅	NextAuth secret (openssl rand -base64 32)
AUTH_GOOGLE_ID	✅	Google OAuth client ID
AUTH_GOOGLE_SECRET	✅	Google OAuth client secret
AUTH_URL	✅	App URL (e.g. https://lunchvote.example.com)
ALLOWED_EMAIL_DOMAIN	✅	Only this Google Workspace domain can sign in
ADMIN_EMAILS	✅	Comma-separated admin email addresses
CRON_SECRET	✅	Bearer token for Vercel cron routes
OFFICE_TIMEZONE	optional	IANA timezone, default Europe/Rome
POLL_OPEN_TIME	optional	HH:MM poll opens, default 11:30
POLL_CLOSE_TIME	optional	HH:MM poll closes, default 12:30
POLL_MAX_CANDIDATES	optional	Cap on candidates per poll, preferring least-recently-visited places. Unset = no cap
CURRENCY	optional	Currency code, default EUR
SLACK_ENABLED	optional	Set true to enable Slack notifications
SLACK_WEBHOOK_URL	optional	Slack incoming webhook URL

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Cron jobs

Two Vercel cron jobs manage the poll lifecycle:

Job	Path	Default schedule
Open poll	/api/cron/open	09:30 UTC weekdays
Close poll + tabulate	/api/cron/close	10:30 UTC weekdays

Adjust schedules in vercel.json. Both endpoints are secured with Authorization: Bearer <CRON_SECRET>.

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Deploy to Vercel

vercel deploy

Add all environment variables in the Vercel project settings. Vercel will automatically pick up the cron jobs from vercel.json.

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Enabling Slack notifications

Set SLACK_ENABLED=true and SLACK_WEBHOOK_URL=<your-webhook-url> in your environment. No code changes needed — the integration is already wired and gated behind this flag.

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IRV algorithm

The voting system uses Instant-Runoff Voting (IRV):

1. Count each ballot's top-ranked still-standing candidate.
2. If any candidate has a majority, they win.
3. Otherwise eliminate the candidate with the fewest votes.
4. Tie-break: among tied candidates, the most-recently-visited is eliminated (so the least-recently-visited survives). A never-visited place counts as the oldest.
5. Repeat until a winner emerges.

This logic lives in src/lib/irv.ts and is covered by 20 unit tests in src/lib/irv.test.ts.

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License

GNU General Public License