🌾 Mandi Price Aggregator

Real-time agricultural commodity prices from Indian mandis (markets), sourced from the government Agmarknet feed on data.gov.in. Built for farmers, traders, and anyone who wants to know what tomatoes are going for in their nearest market today.

---

What it does

• 🔎 Search & multi-select commodities and states — pick Tomato + Onion across Karnataka + Tamil Nadu in one query
• 💰 Ranked prices per mandi: modal ₹/kg, min–max range, variety, district, "as of" date
• 🌐 8 Indian languages — English, हिन्दी, मराठी, ಕನ್ನಡ, नेपाली, தமிழ், తెలుగు, বাংলা (cookie-persisted)
• 🌙 Light · Dark · System theme, warm Claude-inspired palette
• 📱 Mobile-first — sticky header, touch-sized controls, installable PWA (manifest + icons)
• 🔁 Daily auto-ingest at 6 PM IST via Vercel Cron — no manual refresh
• 📡 JSON API for power users: /api/prices?commodity=Tomato&state=Karnataka

How it works

┌──────────────────────────────┐
│ data.gov.in Agmarknet API    │  free, public, daily-updated mandi feed
└──────────────┬───────────────┘
               │ paginated fetch (1 page = 1000 records, cap ~10k/day)
               ▼
┌──────────────────────────────┐
│ /api/cron/ingest             │  Vercel Cron · 30 12 * * * UTC = 6 PM IST
│ (Next.js Route, node runtime)│  · Bearer CRON_SECRET auth
└──────────────┬───────────────┘
               │ upsert in 500-row batches, dedupe by (mandi, commodity, variety, date)
               ▼
┌──────────────────────────────┐
│ Supabase Postgres            │  free tier · 500 MB · public-read RLS
│  states / districts / mandis │
│  commodities / price_records │
└──────────────┬───────────────┘
               │ public-read via anon key
               ▼
┌──────────────────────────────┐
│ Next.js App Router (SSR)     │  picker → /prices?commodity=X&state=Y
│ shadcn/ui + Tailwind v4      │
└──────────────────────────────┘

---

Stack

Layer	Choice	Why
Framework	Next.js 16 App Router + TypeScript	SSR, route handlers, Vercel Cron native
Styling	Tailwind v4 + shadcn/ui	Mobile-first utilities, accessible primitives
Database	Supabase (Postgres)	Free 500 MB, instant REST, row-level security
Data source	data.gov.in Agmarknet	Official, free, no scraping
Cron	Vercel Cron	1 job/day on free hobby tier
Hosting	Vercel free hobby	$0 at any reasonable traffic
Themes/i18n	next-themes + cookie-based dictionary	No client routing changes

Estimated cost at <10K daily users: $0.

---

Quick start (local)

# 1. Clone + install
git clone https://github.com/skalkii/mandibazar.git
cd mandibazar
pnpm install

# 2. Configure env
cp .env.example .env.local
# fill in 5 values — see "Environment variables" below

# 3. Initialize the database
# Open Supabase SQL Editor → paste db/schema.sql → Run

# 4. Seed some data
pnpm seed              # last 3 days (override with SEED_DAYS=N)

# 5. Start dev server
pnpm dev               # → http://localhost:3000

Pick a commodity + (optional) state → click See prices → ranked list of mandis.

---

Environment variables

Copy .env.example to .env.local and fill these 5 values:

Variable	Where to get	Notes
NEXT_PUBLIC_SUPABASE_URL	Supabase Dashboard → Project Settings → API → "Project URL"	Just the base, no /rest/v1/ suffix
NEXT_PUBLIC_SUPABASE_ANON_KEY	Same page → "Project API Keys" → anon public	Safe in browser; RLS protects data
SUPABASE_SERVICE_ROLE_KEY	Same page → "Project API Keys" → service_role	⚠️ Server-only. Bypasses RLS. Never commit.
AGMARKNET_API_KEY	Register at https://data.gov.in/user/register → profile → "API Key"	One key per account; works for any dataset
CRON_SECRET	Generate: openssl rand -hex 32	Used to auth the ingest endpoint

Optional tuning:

Variable	Default	What
SEED_DAYS	3	Days back pnpm seed ingests
BACKFILL_DAYS	30	Default for pnpm backfill with no arg

---

Scripts

Command	What it does
pnpm dev	Start Next.js dev server
pnpm build	Production build (compiles routes + types)
pnpm start	Run production build locally
pnpm lint	ESLint
pnpm typecheck	tsc --noEmit
pnpm seed	Ingest the last $SEED_DAYS days (default 3)
pnpm backfill [days]	Ingest the last N days (e.g. pnpm backfill 30)
pnpm tsx scripts/smoke.ts	Verify Supabase connection + row counts

---

Database schema

states          (id, name)
districts       (id, state_id, name)
mandis          (id, district_id, name, latitude?, longitude?)
commodities    (id, canonical_name, hindi_name?, kannada_name?, category?)
price_records   (id, mandi_id, commodity_id, variety, arrival_date,
                 min_price_per_quintal, max_price_per_quintal,
                 modal_price_per_quintal, ingested_at)
                 UNIQUE (mandi_id, commodity_id, variety, arrival_date)

All tables have public-read RLS policies. Writes only via service-role key (cron + seed scripts). See db/schema.sql.

Migrations live in db/migrations/. Run them in Supabase SQL Editor after the base schema.

---

API

Read-only JSON endpoints:

GET /api/commodities
→ { "commodities": ["Ajwan", "Apple", …] }

GET /api/locations
→ { "states": ["Andhra Pradesh", "Bihar", …] }

GET /api/locations?state=Karnataka
→ { "districts": ["Bagalkot", "Bangalore", …] }

GET /api/prices?commodity=Tomato&commodity=Onion&state=Karnataka
→ {
    "commodities": ["Tomato", "Onion"],
    "states": ["Karnataka"],
    "latest_date": "2026-05-14",
    "count": 38,
    "prices": [ { mandi, district, state, modal_per_kg, … } ],
    "byCommodity": { "Tomato": [...], "Onion": [...] }
  }

Multi-value: repeat the param key (?commodity=A&commodity=B).

---

Deploy to Vercel (free)

1. Sign in: https://vercel.com → "Continue with GitHub".
2. Add New → Project → import this repo.
3. Click Environment Variables → paste the same 5 keys from your .env.local. Mark the 3 server-only ones (SUPABASE_SERVICE_ROLE_KEY, AGMARKNET_API_KEY, CRON_SECRET) as Sensitive.
4. Deploy. ~90 sec → live at https://mandibazar-<hash>.vercel.app.
5. Cron auto-wires from vercel.json (30 12 * * * UTC = 6 PM IST). Vercel injects Authorization: Bearer ${CRON_SECRET} automatically.

Smoke test:

• https://your-app.vercel.app/
• https://your-app.vercel.app/api/commodities
• https://your-app.vercel.app/api/prices?commodity=Tomato&state=Karnataka

Free tier limits (all comfortable)

Service	Free tier	This app's load
Vercel	100 GB bandwidth/mo	JSON tiny, far below
Vercel cron	2 jobs / day	Uses 1
Vercel funcs	100k invocations/mo	Page reads cheap
Supabase	500 MB storage	~10k rows/day fits easily
data.gov.in	~100 req/min	1 cron/day, ~10 calls

---

Project layout

app/
  api/
    cron/ingest/route.ts    # daily ingest (Bearer-auth'd)
    commodities/route.ts    # GET commodity list
    locations/route.ts      # GET states or districts
    prices/route.ts         # GET filtered prices (multi)
  prices/page.tsx           # results SSR
  page.tsx                  # landing (picker)
  layout.tsx                # theme + i18n + header + footer
  globals.css               # Tailwind v4 + theme tokens

components/
  ui/                       # shadcn primitives (button, card, select, …)
  Header.tsx                # sticky, theme + lang switchers
  Footer.tsx                # data attribution + GitHub
  PickerForm.tsx            # commodity + state multi-select
  MultiSelect.tsx           # searchable, multi, chips
  PriceCard.tsx             # ranked mandi card
  ThemeProvider.tsx         # next-themes wrapper
  ThemeToggle.tsx           # light/dark/system
  LanguageSwitcher.tsx      # 8 locales, cookie

lib/
  agmarknet.ts              # data.gov.in API wrapper (retry, content-type guard, paginator)
  ingest.ts                 # upsert pipeline (dedupe + 500-row batches)
  prices-query.ts           # shared price query (used by /api/prices + /prices SSR)
  queries.ts                # commodity + state list helpers
  supabase.ts               # browser + server clients
  format.ts                 # INR + date formatters (Intl)
  normalize.ts              # DD/MM/YYYY parse, canonical names, quintal→kg
  types.ts
  utils.ts                  # cn() helper
  i18n/
    dictionaries.ts         # 8 locale strings
    server.ts               # getLocale() via cookie

db/
  schema.sql                # full schema + RLS — paste into Supabase
  migrations/               # ordered ALTERs

scripts/
  _env.ts                   # loads .env.local then .env
  seed-locations.ts         # pnpm seed
  backfill.ts               # pnpm backfill N
  smoke.ts                  # connection + row count check

public/
  favicon.svg, favicon.ico, apple-touch-icon.png, icon-192/512.png
  site.webmanifest          # PWA installable

---

Adding a new language

1. Open lib/i18n/dictionaries.ts.
2. Add the locale code to the LOCALES tuple and LOCALE_NAMES map.
3. Copy the en dictionary, translate each value.
4. Add it to the dictionaries record at the bottom.

That's it — switcher picks it up automatically.

---

Common gotchas

• PGRST125 Invalid path on Supabase calls → your NEXT_PUBLIC_SUPABASE_URL includes /rest/v1/. Strip it; use just https://<ref>.supabase.co.
• invalid input syntax for type integer during seed → migration 001_prices_to_numeric.sql not run, or you're on an old lib/ingest.ts that didn't round. Latest code rounds at the boundary, so any int column accepts the data.
• Empty pickers in dev → no seed yet. Run pnpm seed once.
• Empty results for "Karnataka + Tomato" right after first seed → first seed sometimes truncates due to the rare duplicate-in-batch issue; re-run pnpm seed.
• Cron returns 401 in Vercel → CRON_SECRET env var isn't set in Vercel project settings.

---

Roadmap

• WhatsApp deep-link share button
• Geolocation auto-detect nearest district
• 7-day modal-price trendline per mandi
• Saved searches + email/WhatsApp digest
• Hindi/Kannada commodity name secondary labels (currently UI-only i18n)
• Map view
• SMS interface (Twilio India)

---

License

MIT.

---

Credits

• Data: data.gov.in Agmarknet · Ministry of Agriculture and Farmers Welfare
• UI primitives: shadcn/ui
• Icons: lucide
• Fonts: Inter, Newsreader, Geist Mono