Gm CKB community,
The FiberNuts Community Market is now open for public testing on CKB Testnet: https://market.fibernuts.xyz
The aim is to make Cashu + Fiber easy to experience as an application. An attendee can claim 10 test RUSD from a bounded, project-operated faucet directly into the browser, without running a Fiber node. A vendor can prepare a RUSD charge for something simple such as a coffee, the attendee can scan or paste the request, and the vendor’s balance changes only after the received Cashu token has been checked and swapped for fresh proofs at the mint.
I ran that complete flow against the public deployment. The screenshots below are from the same live CKB testnet payment.
1. Claim test RUSD. The attendee first reviews the amount, CKB Testnet network, issuing mint, and remaining daily availability.
The faucet then pays through Fiber. The spendable balance changes only after the mint has issued fresh proofs and they have been persisted in the browser.
2. Create the vendor charge. The vendor creates a mint-bound 2.50 RUSD request for one coffee. The request shown here has already been completed and is no longer payable.
3. Review before paying. The attendee sees the vendor, issuing mint, proof fee, exact debit, resulting balance, and current no-refund limitation before confirming.
4. Keep delivery separate from settlement. After delivery, the attendee sees that the payment is waiting for the vendor. Delivery alone does not make the vendor balance spendable.
5. Settle at the mint. The vendor marks the order paid only after the mint accepts the received token, returns fresh proofs, and those proofs are stored. The completed test left the attendee with 7.50 RUSD and the vendor with 2.50 RUSD.
![Vendor payment settled with fresh proofs]
This remains testnet value only. The mint is custodial and controls issuance and redemption. The faucet is rate-limited and records aggregate claim demand; it is only there to remove the funded-node prerequisite from this test. Cashu blind signatures limit direct issuance-to-redemption linkage, but they do not hide timing, amount, network, browser, or mint-policy metadata.
The demo is now open for community testing. If you can spare five minutes:
- Open https://market.fibernuts.xyz and claim 10 test RUSD.
- Create a small vendor charge and complete an attendee-to-vendor payment, ideally with another person or a second device.
- Reply here with whether you completed the flow, where you became confused or blocked, and whether you would use an experience like this at a meetup, community market, or another real setting.
Successful and failed attempts are both useful. Please do not include Cashu tokens, Fiber invoices, or other bearer payment data in screenshots or replies. The goal is to learn from actual community use: whether people can onboard, whether the flow is understandable, and which real use cases are worth developing further.