Keep keys on hardware.
Match the card’s public key to your address. The workflow does not require exporting a private key or entering a seed phrase.
Independent tools. Practical mining.
Your node.
Your card.
Your XBT.
A signing workflow for XBT holders using Tangem hardware. Built from real mining experience, with control kept in your hands.
XBT Card Signer · Android · Personal testing candidate
BLAKE2b / XBTTANGEM HARDWAREWATCH-ONLY WALLETSDATUM & MINING INFRASTRUCTURE
01 / Featured project
XBT Card Signer
An independent Android companion for signing XBT transactions with an existing Tangem card. The phone handles card access; your node handles the chain.
Review what you sign.
Inspect recipient addresses, amounts, change and the total fee before explicitly authorizing a card signature.
Use your own validation.
Exchange unsigned and signed PSBTs. Finalize, check acceptance and broadcast on your XBT-aware Knots node.
Independent project, built for the XBT chain.
Not an official Tangem product or an endorsement by Tangem. Ordinary Bitcoin wallet support does not establish XBT compatibility. This website provides reference material; it does not connect to a card or sign transactions.
02 / Project status
Evidence first.
Release second.
The earlier 0.3 signing engine completed a confirmed real transaction. The redesigned 0.4 candidate has software test coverage; physical-device acceptance remains to be completed.
Read testing & release notesCurrent candidate0.4.0-rc1 · personal testing
Card transaction evidence0.3 · Tangem / Pixel 7 Pro / Knots
Public app downloadNot available yet
Google Play & GitHubPublic launch pending
Before public distributionSDK rights clearance & device testing
03 / Beyond signing
Built around
the mining floor.
ACME Crypto draws on hands-on work with BLAKE2b ASICs, mining rentals, XBT nodes and DATUM gateways. Equipment resale and consulting are planned additions.
Mining hardware.
A future home for equipment listings with clear model details, condition, observed performance and power requirements.
BLAKE2b ASICsUsed equipmentParts & maintenance
Mining infrastructure.
Practical help with node deployment, DATUM gateways, pool connectivity and evaluating mining economics.
Knots nodesDATUMFleet planning
04 / Common questions
A few things to know.
Can I download the app today?
There is no public download yet. The current build is a personal testing candidate. Distribution of its Tangem SDK integration requires rights clearance, and the 0.4 interface still needs physical-device acceptance.
Can this website sign with my card?
No. The Android app performs NFC card access. This site explains the workflow and provides documentation. It does not accept PSBTs, private keys, access codes or seed phrases.
Is this the official Tangem wallet?
No. XBT Card Signer is an independent project for XBT transaction signing using Tangem hardware. It does not replace the official Tangem wallet or reset your card.
Are hardware sales or consulting available?
These are planned services. No equipment inventory, checkout or consulting bookings are open on this site yet.