About

Cashumints.space lists every Cashu mint we can find on the Nostr network and shows you what people say about them. It is made by Azzamo.

What Cashu is

Cashu is an ecash protocol for Bitcoin. A mint issues blinded tokens backed by sats it holds, and those tokens move between people without the mint learning who sent what to whom. The privacy is real and it is the point: tokens are not accounts, and the mint cannot link the token it signed to the token that comes back.

You can read the protocol and its specifications at cashu.space. The specifications themselves are called NUTs, which is where the NUT numbers on every mint page come from.

What a mint is, and the tradeoff

A mint is custodial. When you mint ecash you are handing sats to whoever runs that server, and you are trusting them to honour the tokens when you melt them back out. There is no fraud proof, no escrow and no recourse. A mint operator can disappear with the balance, and mints have.

That is exactly why reviews exist here. This site never tells you a mint is safe. The status on a mint page says online, not "trusted", and it only means the server answered when we last asked. Treat ecash balances like cash in a coat pocket: fine for spending, wrong for savings.

What NIP-87 is

NIP-87 is the Nostr convention for announcing and recommending ecash mints. Two event kinds matter here:

• kind 38172 announces a mint. The mint URL is in the u tag. This is how the site discovers mints it has never seen.
• kind 38000 is a review. It carries the rating and the review text, and points at the mint it is about with a u tag (the mint URL) and a d tag (the mint's own public key).

Every review is signed by its author's Nostr key. We never call a review "verified", because nobody verified it: it is signed, which is a different and more useful claim. It means you can check who wrote it and that it was not altered. It does not mean the author is honest or ever used the mint.

How this site works

There are two loops and one rule. The rule is that the mint owns its metadata and Nostr owns the reviews, so this site stores neither as an authority.

• The probe loop asks every known mint for /v1/info every ten minutes and records what it says: name, description, version, supported NUTs, limits, contact details. It also records whether the mint answered at all, which is where uptime comes from.
• The discovery loop connects to Nostr relays every hour, reads mint announcements and reviews, and adds any mint it has not seen before.

The important part is what happens when a mint stops answering. Its cached metadata is never overwritten by a failed probe, so a dead mint keeps its full page: its specs, its history and its reviews, with a banner saying when it went dark. The previous version of this site showed an error page instead, which meant the mints people most needed to warn each other about were the ones that could not be reviewed. That was the main reason for the rebuild.

Review text is never stored on our side. When you open a mint page your browser talks to the relays directly and reads the reviews itself, and when you write one it is signed by your own Nostr extension and sent straight to those relays. We keep a count so the pages can be ranked and sorted, nothing more. Nothing here can be edited or deleted by us, including reviews we would rather not have.

Relays we read

These are the relays the indexer and your browser both use:

• wss://relay.cashumints.space
• wss://nos.lol
• wss://relay.azzamo.net
• wss://relay.snort.social
• wss://relay.primal.net

Point any Nostr client at the same relays and you will see the same events. That is the whole promise: nothing here is only true because we say so.

What are NUTs?

NUTs are the numbered Cashu specifications, like BIPs for Bitcoin. A mint advertises which ones it implements, and that tells you what it can actually do: NUT-04 and NUT-05 are minting and melting over Lightning (without them a mint is not much use), NUT-07 lets a wallet check whether a token was already spent, NUT-17 gives wallets live updates over WebSockets instead of polling, and NUT-20 lets a wallet prove a mint quote was really issued to it. The full list is at github.com/cashubtc/nuts.

Right now

58 mints indexed, 34 of them answering, 591 reviews counted from the relays above.

Source and credit

The site is open source at GitHub. It is built and run by Azzamo. If a mint page has something wrong on it, fix it at the source: mint metadata comes from the mint's own /v1/info, and reviews come from Nostr.