Calle, a pseudonymous physicist and key figure behind the Cashu ecash protocol, is working with a team on a new project called the Internet Mint Finder (IMF). The initiative, announced on October 27, 2026, aims to list Cashu mints that have been announced or reviewed on Nostr, the open, decentralized messaging network popular in Bitcoin circles.
What the Internet Mint Finder does
Cashu is an open-source Chaumian ecash protocol built for Bitcoin. A mint is the service that issues ecash, so every Cashu user relies on one. The IMF pulls its data from Nostr and is built on NIP-87, a recently drafted Nostr specification. A NIP, or Nostr Implementation Possibility, is a shared rulebook that lets different apps understand the same kind of message.
NIP-87 defines two standard event types: kind 38172 for mint announcements and kind 38000 for user reviews. Mint operators can post a standardized announcement, and users can post standardized feedback. Any app that supports NIP-87 can read both and assemble a picture of the mint landscape.
The team has not shared a launch timeline or detailed which features will set the IMF apart from existing tools.
A growing toolkit around Cashu
The IMF is not arriving in an empty room. Cashumints.space, another community project, already indexes mint information and aggregates reviews. As of October 5, 2026, it reported tracking 63 mints, of which 34 were online, and had logged 962 reviews.
The cashu.me web wallet has also moved in this direction. It now offers mint discovery and ratings based on user-generated Nostr data, a recent upgrade to its interface.
Why mint discovery matters
For Cashu, the mint is the point of trust. Users hand their Bitcoin to a mint in exchange for ecash, so knowing which mints are live and how others rate them is not a nice-to-have.
A standardized format like NIP-87 changes the dynamics in a quiet but meaningful way. Reviews posted once can surface across multiple apps, including the IMF, cashu.me, and whatever comes next.
There are open questions. Any review system built on open participation has to handle low-quality or manipulative feedback, and the IMF will be judged on how well it separates signal from noise. The other test is differentiation: with Cashumints.space already tracking dozens of mints and hundreds of reviews, and cashu.me offering Nostr-based ratings, the IMF will need to show what it adds beyond another window onto the same data.
On the market side, there is no token attached to any of this. Cashu operates without a traded asset of its own, so the IMF is not a trading story.
