LICENSE — License

Shows the license status and lets you activate it, start a trial or release it on this machine.

Command: LICENSE · Global name: _LICENSE
Ribbon: Manage › Help
Menu: LinceCAD
Menu: Help

Shows the LinceCAD license status and lets you buy the license, activate a seat, redeem an invitation, start a 30-day trial or release the license on this machine to move it to another one.

Usage

Type LICENSE or click License.
At the top, a badge sums up the status: Full license, Temporary license · until D, Trial · days left, Offline · grace days left or Read-only. Below it, the type (perpetual, temporary or trial), email, seats, expiry and the date of the last online validation.
To buy it, click Buy license… (see below).
To activate, paste the key you received by email when you bought it (or the one support gave you) and click Activate.
If you have an invitation code, click I have an invitation…, enter it and click Redeem (see below).
To try it, enter your email and click Start trial.
To move the license to another machine, click Release on this machine… and confirm. Then activate it on the new machine with the same key.

Buying the license

The Buy a license section appears while there is no perpetual license (no license, on trial or with the trial expired). It shows the price of the perpetual license for one machine; taxes are calculated at checkout for your country.
Buy license… asks the license server for a Stripe payment page for this machine and opens it in your browser. The server only receives the machine fingerprint (stored as a SHA-256 digest); Stripe only gets a purchase reference and that digest.
While you pay, the dialog shows Waiting for the payment… and checks every few seconds, also with the dialog closed. Open the payment page again reopens it; Stop waiting stops checking (if the payment completes anyway, Check the pending payment picks it up).
Once the payment is confirmed, the server creates the perpetual license and activates it on this machine (it uses its seat): LinceCAD switches to Full license by itself, without typing any key.
You receive the license key by email (keep it: you need it to move the license to another machine) and, separately, the payment receipt and invoice from the payment platform.
If you close LinceCAD before the payment arrives, reopening LICENSE resumes the check. An unused payment page expires after one hour and the purchase is cancelled.
Without a connection to the server you cannot buy from here; the Pricing and terms on lincecad.com link opens the website.

Invitation

LinceCAD can give away full licenses, perpetual or temporary, with an invitation code of the form LINCE-XXXX-XXXX-XXXX-XXXX (for example for the press, collaborators, schools or giveaways). It usually arrives by email, with what it includes and the deadline to redeem it.
Click I have an invitation…, enter the code and click Redeem. Lower case, spaces or missing hyphens do not matter.
The server creates the license and activates it on this computer: LinceCAD shows Perpetual license activated or Temporary license activated until D and switches to the full license, without typing any key.
If the code does not exist, has already been used or is past its deadline, the dialog says so; for security it does not tell those cases apart, and after several failed attempts you have to wait a while.
Redeeming the same code again on the same computer does not use it up again: it returns the same license.
A temporary license works like a perpetual one until its end date. 15 days before, the start screen and this dialog warn you: «Your temporary license ends on D». When the date arrives (also with the program open) it switches to read-only with the courtesy save; to keep editing, buy the license or redeem another invitation.

Start screen

With no license, a running trial or an expired trial, the start screen says so and waits for a button:

No license: "To activate the 30-day trial version, press the button" and Activate the trial version, which opens this dialog.
Trial running: "Trial version: N days left" and Buy license….
Trial expired: "The trial version has expired" and Buy license….
Temporary license 15 days or less from its end: "Your temporary license ends on D" and Buy license…; once ended, "Your temporary license has ended".
Continue (or Esc) closes the screen. With a perpetual license the start screen goes away by itself, as always.

Moving to another machine

When you release it, the server deletes this machine's activation and LinceCAD deletes the local token: this machine goes back to no license (read-only) and the seat is free for another one.
Each license allows 3 transfers in a rolling 12 months (every release in the last 365 days counts). Beyond that, LinceCAD tells you so and only LinceCAD support can release it from the panel (for example, for a broken or stolen machine; those releases do not use up transfers).
A trial can also be moved, but it does not entitle you to another trial on the same machine.

Online validation and grace period

At startup and every 12 hours while the program is open, LinceCAD checks the license with the server in the background: it does not delay startup or block your work.
If the server answers that the license is revoked, does not exist or is no longer activated on this machine (it was released elsewhere), LinceCAD switches to read-only immediately.
If there is no answer (no internet or the server is down), the license stays full for 7 days from the last successful validation; the badge shows the grace days left. After 7 days, it switches to read-only.
As soon as it validates successfully again, the full license comes back with no further action.
This applies to perpetual licenses and trials; the trial expiry (30 days) is still checked on the machine itself.

Maintenance (updates)

The perpetual license includes one year of updates. The Updates until row and the Maintenance section show Updates included until: … or, if it has passed, Maintenance expired on ….
Renew maintenance… opens the Stripe payment, like the purchase; once paid, maintenance is extended one year from its end date (or from today, if it had expired) and a confirmation email is sent.
If this version was released after the end of maintenance (for example, installed by hand), LinceCAD switches to read-only with a courtesy save, also offline, and explains it here and on the start screen. See License and maintenance.

Courtesy save

If the license is cut off or expires (trial or temporary) while you work, LinceCAD warns you and opens this dialog. Each drawing that had unsaved changes at that moment can be saved once (SAVE or SAVEAS) so you do not lose your work; after that it is read-only like the rest.

Evaluation mode (read-only)

Without a valid license, LinceCAD runs in evaluation mode: you can open, view, pan and zoom, query, plot and export to PDF, PNG or SVG and print, but you cannot edit or save the drawing. Drawing and editing commands and SAVE/SAVEAS are blocked, with a discreet notice in the status bar.

How it works

The license is signed by the server with Ed25519. The client embeds the public key and verifies the signature offline.
Activation, trial sign-up and release send a machine fingerprint (a stable machine identifier); the server only stores its SHA-256 digest. The returned token is stored in <config>/lince/licencia.json.
The online validation answer is signed too and includes a random value the program picks for each check: a copied or forged answer does not work.
A trial lasts 30 days; when it expires, LinceCAD returns to evaluation mode.
The pending purchase is stored in <configuration>/lince/compra.json (reference and query code, no payment data) and deleted once paid or cancelled.

Limitations

The grace period is measured with the machine's clock.
The license is bound to the machine by its fingerprint: copying licencia.json to another machine does not activate it there.