About

Built on a golf course.
Fixed on a golf course.

OnTheBag was built by a golfer who was tired of generic advice and forgotten stats. The app you'd actually use during a round — not afterwards.

The idea

Why does every golf app expect you to log shots after the round?

Most golf apps are statistics tools. You finish the round, sit down, and tap in everything you remember — which by hole 12 is already a blur. The data's stale before it's entered.

OnTheBag flips that. It's built for the course, not the clubhouse. Three taps per shot, mid-round. The caddie advice is pre-fetched before you reach your ball. The stats build themselves while you play.

The name comes from having a caddie who knows your game — the one who's watched every shot, knows your 7-iron flies 142 not 150, and tells you to take one more club when the wind picks up. That's what we're building.

How we build

A few things we believe.

Speed is a feature

If the app slows you down on the course, it's useless. Every interaction is optimised for one thumb, mid-round. No loading spinners where they matter.

Your data, not averages

Generic tips are everywhere. OnTheBag reasons from your actual history — your misses, your strengths, your tendencies. The caddie gets smarter the more you play.

Free first

Unlimited rounds and shots, free forever. We earn when the caddie earns your trust. Pro is a choice, never a paywall on the basics.

Under the hood

What powers OnTheBag.

The AI caddie is powered by Claude — Anthropic's model — called from our own edge functions so your shot data never sits in a third-party system. The system prompt is golf-specific: it leads with the club, backs it with your data, and never hedges.

Shot data lives in Supabase with row-level security — only you can read your rounds. The app works offline first, syncing when you're back online. Golf courses don't always have signal.

The app is built with React Native via Capacitor, deployed to iOS and Android from a single codebase. It's a small team and we ship fast.

Try it on your next round.

Free to download. No credit card. Start logging your first round in under a minute.

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