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Japan launch day: Mercari works, Amazon blocked, payment stuck

On launch day an engineer tried Muse in Japanese. An Amazon order failed with Amazon's error page stuck in Muse's browser. A Mercari search worked, listing the cheapest option per capacity, though some descriptions didn't match. A movie booking used his past booking emails to infer preferences and avoided seats beside existing bookings, but payment first used an expired card and then failed 3D Secure, even after he took over; an hour later it still wasn't done.

H@hisashi-ito ·2026-10-23 ·qiita.com

Try it yourself

Copy this to Muse and replace the [brackets] with your own details:

Search Mercari for [item] and list the cheapest option for each [size or spec], noting condition and shipping; I'll choose.

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