Features
Sign-in, time limits, reservations, guest passes and a clean PC for every user. One product, with no server to maintain.
Carrel runs on Windows PCs today. Agents for Mac, ChromeOS and Linux are coming next. Staff and the reservation portal work in any modern browser.
What sets Carrel apart
- No Deep Freeze, Reboot Restore Rx or CleanSlate. When a session ends, Carrel deletes that person’s documents, downloads, browser history, cookies and saved passwords, empties the Recycle Bin and clears Windows’ recent files. Then it signs out, and the PC is ready for the next person without a restart. You choose what to keep, such as settings for software in a makerspace.
- Clean even after a power cut. If a PC loses power or crashes mid-session, Carrel finishes the cleanup the next time it starts, before anyone can sign in. If it still can’t, staff are told.
- Move reservations to another PC. When a PC breaks, transfer its current and upcoming reservations to a replacement. Before anything changes, Carrel lists what the move would do, such as ending someone’s session or breaking a time limit, and waits for you to confirm.
- Guest passes designed by you. Add your logo and your own text, pick the barcode type and number format, and check a sample receipt before you print a real one. Print one pass, or a batch for a busy day or a class visit. See what you can change.
- Class and event bookings. Reserve a whole lab, a section or a set of PCs for a class. One shared pass works on those PCs, only for that booking, and every session ends together.
Sign-in
- People sign in with their library card or student ID and PIN, checked against your library system over SIP2.
- Block sign-in when fines are over a threshold you set.
- Names come live from your library system and are shown on screen. Carrel never stores them.
- Guest passes work even when your library system is down.
Rules and limits
Set rules once for every location, then change only what’s different. Each layer inherits from the one above it, field by field.
| Layer | What it’s for | Example |
|---|---|---|
| All locations | Your defaults | 60-minute sessions, 2 hours a day |
| Location | A building’s own hours and rules | Downtown closes its PCs at 9 PM |
| Group of PCs | A kind of PC, at every location | Express PCs get 15-minute sessions |
| Group at one location | One building’s version of a group | Express PCs at Main get 10 minutes |
| Section | A room or floor in one building | The teen room is for ages 12 to 18 |
| Age group | People, wherever they sign in | Children get 30-minute sessions |
What you can set at each layer
- Session length, and daily, weekly and 28-day limits. Weekly and 28-day periods reset on the weekday you choose.
- Whether a group or section shares the building’s daily time or has its own. Express PCs can have a separate 30 minutes a day that doesn’t use up anyone’s regular time.
- Which age groups may use the PCs. Age groups come from patron types or from a birth date in your library system, and the birth date is never stored.
- Reservations: how many days ahead people can book, when no-shows are released, whether PCs are walk-up only, and whether they’re held for the waitlist.
- Automatic extensions: on or off, how long each one is, how many per session, and whether “someone waiting” means anyone in the building, for that group or in that section.
What people see
When someone reaches a limit, the sign-in screen tells them which one and when it resets, for example “You have used your computer time for this week (5 hours). It resets on Sunday.” Staff can see each person’s time today, this week and this period, and staff extensions aren’t limited.
All of this is enforced on the PC itself, so it still works when the network is down.
More session controls
- Sessions stop at closing time, and you can require people to accept your terms of use.
- Auto-extend when no one is waiting. At the first warning, Carrel checks whether anyone is waiting or has a reservation coming up. If not, the session extends and the person sees a short notice.
- Guest passes can have their own, lower daily limit.
Reservations and waitlists
- A mobile-friendly web page shows which PCs are free and lets people reserve one or join a waitlist for a location, group or section.
- When a PC frees up, it’s held for the next person waiting, and they get a text or email.
- Reservations nobody signs in to are released after the number of minutes you choose, so PCs don’t sit empty.
- Mark PCs as walk-up only, or take a PC out of service, and reservations work around it.
- A reserved PC shows who it’s held for and until when, even while it’s offline.
The lock screen
- Sign-in with a card or ID and PIN, a countdown, and warnings before time runs out.
- Your logo, colors and wording. See Make it yours.
- Designed for WCAG 2.2 AA, with keyboard-only sign-in and screen reader labels.
Make it yours
Carrel should look and sound like your library, not like us. You see changes before anyone else does.
The sign-in screen and timer, previewed as you type
- Title and welcome text, for example “Welcome to Main Library” and a line about your hours or Wi-Fi.
- Your logo and colours: a background colour for the sign-in screen, a button colour, and a timer colour for the session timer people see while they work. A colour picker sits beside each one.
- Readable whatever you choose. Carrel picks white or dark text for each colour, so gold buttons get dark text and a navy background gets white. It refuses buttons that don’t stand out from the background, and colours where no text would meet WCAG contrast (4.5:1).
- A live preview beside the settings shows the sign-in screen exactly as people will see it, with the session timer in its corner, and updates as you type. Nothing reaches the PCs until you save.
- Different screens for different places. Set a title, text and colours for all locations, then change them for one location, a group of PCs or a section, such as a teen room. The preview shows the version for the place you’re editing.
- Your words. Choose whether Carrel talks about patrons or customers, library cards or student IDs, the library or the school. Pick a preset for a library, school, college or university, or write your own. The lock screen, timer warnings and messages all follow it.
- Terms of use, if you want people to accept your rules before each session.
- The session timer: choose its corner of the screen, and whether it tucks itself away after a while. Warnings always stay visible.
Guest pass receipts, with a sample before you print
- Paper: 80 mm or 58 mm receipt printers.
- What’s printed: your logo, a heading, the barcode and pass number, an optional 4-digit PIN, the minutes a day (or leave the time off), the last day it’s valid, and your own text at the bottom, such as the Wi-Fi password, house rules or opening hours.
- Numbers your scanners already read: a prefix of your choice, the length, and a Mod 10 (Luhn) check digit if your cards use one. Carrel warns you if a format can’t be printed in the barcode you picked.
- Barcodes: Codabar, Code 39, Code 128, Interleaved 2 of 5 or QR.
- A sample receipt with a made-up number appears beside the settings, so you can check the layout before printing a real pass.
- Print without a dialog on a staff desk’s USB or network receipt printer, or from the browser on any printer. Print one pass, or a batch for a class visit.
- Passes for a class or event say on the receipt that they’re for one session and which computers they work on.
Blocked programs
- Close command lines, script hosts and system tools, such as Command Prompt, PowerShell and the Registry Editor, within about a second of someone opening them. A short notice tells them why.
- Renamed copies are caught too: a copy of Command Prompt saved under another name is still closed.
- A sensible list is on by default. Change it, or turn it off, for a location, group of PCs or section, such as a makerspace that needs PowerShell.
- Staff sessions, Windows administrators and your logon scripts are never touched, so a technician can still work on a PC while it’s signed in to the public account.
- Works on every edition of Windows, including Home, with no AppLocker or Group Policy needed.
Works offline
If the network, the server or your library system goes down, PCs keep enforcing your rules and running sessions. Everything syncs back when the connection returns.
Staff console
- A live grid of every PC, with start, extend, end, lock and message controls.
- Look someone up by card or ID.
- See which card or guest pass is signed in to a PC or holds a reservation, then look it up live in your library system. Every look is recorded in the audit log, and you can turn this off.
- Sign in with Microsoft Entra ID or Google. Roles control who can do what, and every staff action goes to an audit log.
- Print guest passes on a staff desk’s receipt printer, USB or network, without a print dialog.
Printing
Carrel passes each person’s identity to PaperCut, so print jobs land on the right account.
Reports
- Sessions and minutes by location, hour and day, plus unique users.
- Export everything to CSV.
Security and privacy
- Names, fines and birth dates are never stored; Carrel asks your library system each time. Card numbers are kept encrypted, only so staff can see who’s on a PC, and are deleted with the session record. Turn that off and only a one-way code is kept.
- Identifiable records are deleted on a schedule you set. Totals are kept for your reports.
- Every PC has its own certificate, which staff can revoke from the console.
- Every visit by Latchwork support is shown in your audit log, with the reason for it.
Coming next
- Agents for Mac, ChromeOS and Linux, so every shared computer runs on the same rules, reservations and console.
- Carrel Print for print release and payment.
- Carrel Kiosk for locked-down catalog and sign-up stations.
- Carrel Rooms for booking rooms and equipment.
They all share the same console, portal and sign-in.