Get the extension What is BC-UR?
BC-UR (Uniform Resources, from Blockchain Commons) is a standard for encoding binary data such as transactions, PSBTs and account keys into QR codes. When the data is too large for one code, it is split into an animated sequence of frames.
Why it matters
A single QR code holds a few kilobytes at most, and dense codes are hard to scan. BC-UR uses fountain codes: the reader can rebuild the payload from any sufficient set of frames, so a missed frame costs a moment, not a restart.
How Locker Protocol Wallet handles it
Locker Protocol Wallet and Locker Vault exchange large requests as BC-UR animated QR codes, the family of formats also used by Keystone and other air-gapped wallets. The Vault caps the size of what it will assemble before it decodes anything.
Questions
Why does the QR code keep changing?
It is an animated sequence carrying a payload too large for one code. Hold the camera on it until the Vault reports it has read everything.
Is BC-UR tied to one wallet brand?
No. It is an open specification from Blockchain Commons, used by several hardware and software wallets.