This AI Calls Pubs to Find Your Cheapest Pint

Jan de Vries · 2026-11-13

Ever wonder if you're paying too much for a pint? Matt Cortland did. As a former pub owner and AI engineer, he turned that nagging question into Guinndex.ai, an AI-powered index that tracks Guinness prices across Ireland. And the results might surprise you. ### The pint-sized problem Cortland's idea wasn't entirely new. Back in 2017, three university students launched the original Guindex, a crowdsourced effort to map Guinness prices, starting in Dublin and later expanding across the Republic of Ireland. They used OpenStreetMap to find pubs and asked the public to submit prices via a website launched in June 2018. Nearly a decade later, Cortland picked up the concept but gave it a tech upgrade. Instead of relying solely on crowdsourced data, he built an AI pipeline to automate most of the work. ### How an AI agent became a price detective The system is surprisingly simple: - **Pub discovery:** Google's Places API maps over 6,500 pubs across Ireland's 32 counties. - **AI-powered calls:** An agent named Rachel, built with ElevenLabs' conversational AI and Twilio's telephony, calls pubs and asks for their Guinness price. - **Data extraction:** Anthropic's Claude scans call transcripts to pull out the quoted prices. - **Website and database:** Next.js and Supabase power the searchable index, with Claude Code helping development. - **Community contributions:** Pub owners and customers can submit new prices and correct listings. But the first version of Rachel was too chatty. She asked extra questions and repeated prices for confirmation. Those longer calls didn't work well. So Cortland simplified: Rachel now asks the price, says thanks, and hangs up. Claude handles the rest. It's a classic case of less is more. ### The numbers are in Guinndex now lists more than 6,500 pubs and thousands of verified prices. At the time of writing, the all-Ireland average was €6.06 (about $6.50), with €5.50 ($5.90) the most common price. The highest? €11.00 ($11.80). The lowest? €3.00 ($3.20). Dublin, as you might expect, is pricey: average €6.93 ($7.45), with three pubs charging €11.00. But even in Dublin, you can find pints under €5.00 ($5.40). Rural pubs often offer better deals, with averages dipping below the national level. > "The Guinndex makes information searchable, accessible, and useful to the people interested in it." Of course, the data isn't perfect. Some pubs don't answer calls, prices change, and community submissions can contain errors. It's not an official survey, but it's a handy tool for pint lovers. ### The transparency question The project also raises a bigger issue: when AI agents call businesses, should they disclose they're not human? The Guinndex now says future calls will begin with a notice. That's a step toward transparency, and it's something more AI projects will have to grapple with as automated interactions become common. So next time you're in Ireland and craving a Guinness, check the Guinndex. You might just save a few euros—or dollars.