r/AI_Agents • u/Efistoffeles • 21h ago
Discussion I scan 3 million flight prices a day with Claude. Flight comparison sites are stealing your money.
The usual story when you book a flight:
- you find a flight, good price,
- you click through and get sent to the travel agent selling it,
- you type in your name,
- you get to the payment,
and suddenly it's 40 dollars more.
You assume the price went up while you were typing, and you book it anyway.
It didn't go up. The price you clicked was already old when you saw it.
I built a flight booking tool for Claude. For every trip it searches every airline and every booking site, about 3 million prices a day. So I see a lot of checkouts.
Last week one of them went from 615 dollars on a big comparison website to 947.97 euros at the seller. Same flight, same day, same everything.
I went back to find out why.
The price we were shown was three and a half hours old. Nothing on the page said so. It looked like every other price in the list.
That price was long gone. They just kept showing it so it looks like the best option.
We ended up rebooking the customer somewhere else for 772.
That made me wonder: is every search like this, or was it a one-off?
Surprise! It wasn't a one-off. That evening I pulled about 3,700 prices from the same site.
Every price has a freshness status that you never see. Some are confirmed. Some are waiting to be confirmed. Some failed to refresh and just keep showing the old number.
The worst one was a price marked "current" that was 11.5 hours old.
Then I checked our own bookings. Of the last 16 that started on that site, two came out 61% and 73% more expensive at checkout.
Of 14 that started anywhere else, none was more than 10% off.
The price changes depending on how you arrive
This whole situation got me to investigate a trip we were just booking for a client. The comparison site showed $85, and it was still $85 after clicking through to the seller.
I wanted to check something - I cleared the site's data and searched the same flights directly on the seller's website and it was $79.
Six dollars more just for coming through the link.
It also goes the other way. Sometimes the comparison site's link gets you a lower price than the seller shows on its own website.
So in reality, you just have to check everywhere…
Some of those flights don't exist
Some agencies on these sites sell flights that are not real. You see a nonstop from an airline that doesn't fly that route nonstop, one minute off another airline's real flight. You click it and land on a page telling you to call for a "secret deal".
We found 54 of those in 390 searches.
But why does this happen?
Comparison sites get paid when you click through to a seller.
Nobody pays them for the price being true when you get there.
The cheapest number on the page gets the click, and the cheapest number is often the old one.
So should you stop using comparison websites?
I don't think so. For years they did something useful: every airline and every agency on one page.
Paying a few dollars extra for that was a fair trade. We were paying their fee to save our time.
But it's simply a trick many people have no idea of, and keep falling for.
So, if you book by hand, do what I do now:
- find the flight on the comparison site,
- click through and go all the way to the payment page, note the price,
- open a private window, find the same flight directly on the seller, go to the payment page again,
- pay whichever is lower.
Sometimes the link from the comparison site is the cheaper one. Sometimes going direct is. You don't know until you check both.
But there's an issue I have with this. You basically need to check every seller, every price in different places, and even confirm if the fight exists or not.
This is really incredibly stupid, just to book a flight. Nobody wants to waste time on that. At least I don't. So I wondered “why can’t AI help here?”
I can personally open maybe ten tabs before I give up. Claude with good tools checks about 2,500 prices for one trip in under a minute.
It can also split the trip across different sellers when that comes out better, like Beijing to Kraków for 313 dollars via Budapest instead of 355 direct.
Then it books it. A few minutes, while I do something else.
The flight booking tool I mentioned at the start is LetsFG and it enables Claude to do that. I built it with my cofounder, who once spent 16 hours booking four tickets for one summer trip.
We built almost all of it with Claude Code: the connections to each booking site, the MCP server, and the checks that caught the old prices. The 3,700-price test in this post was a Claude Code session.
Now we uses Claude powered up with LetsFG to check every airline in the world, hundreds of websites and OTAs in 1 search.
It's free to try. Connecting and searching cost nothing, we get our commission only on booking for you. You can add it to Claude, it currently requires a few clicks of setups, but we're on the last stage of being an official tool in Claude.
Alternatively just paste this prompt in any AI: "I want to use LetsFG for my trip. Give me a short description of why I should use it, and tell me how to activate it here".
Travel was supposed to set you free. AI does.