What is a CRID (Cryptographic Resource ID)?
A Cryptographic Resource ID (CRID) identifies a resource independently of a URL or network location. The CLI prints it when a resource is published. It is derived from the resource public key, so a compatible opener can check that a signed access grant belongs to the expected resource. Identity, location, and permission are separate: keep the name, issue fresh access for each task.
A resource is private or public, and that is chosen when it is published. qurl publish <target-url> publishes a private resource, and qurl publish <target-url> --public publishes a public one. This is so from qurl 3.4.1 on; an earlier release publishes a public resource unless --private is given. A private resource opens only for its publisher’s devices and for the people and devices the publisher allowed. The CRID and the address https://qurl.link/<CRID> of a private resource are safe to send to anyone, so they can go in documentation or a ticket. When the publisher turned access requests on, a person asks for access at that address and gets a six-digit code, and the publisher approves that person by the code. A public resource can be opened by anyone who has its CRID: open https://qurl.link/<CRID> in a browser and press Open anyway. The button reads Open when LayerV has verified the publisher. No account, sign-in, or install is needed. So share the CRID of a public resource only where you would share the resource itself. An authorized owner also uses the CRID to request access links. It stays stable across stops and restarts of the same resource; deleting the resource retires that identity.
How LayerV Implements This
Run qurl publish to create or find a resource, qurl status <CRID> to inspect its local state, and qurl share <CRID> to issue an access link. Send the returned link to a recipient who needs access. Or, with qurl 3.4.1 or later, turn access requests on for that resource with qurl requests <CRID> --on (for a new resource, publish with --allow-requests instead), send people https://qurl.link/<CRID>, and approve each person with qurl approve <CRID> <code>, by the code that person gave you. Approve a code only when it came from the person you mean to let in, over a channel where you know it is them. Keep the CRID for managing the resource.