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Connecting printers

Install the relay client and share printers

Make the printers of a Windows, macOS or Linux computer available as destinations.

The relay client is a small program for the computer your printers are attached to, by USB or on the local network. It fetches jobs from Sealed Print over an outgoing connection and hands them to the printer. No ports are opened on site, the firewall stays closed, and documents stay within Sealed Print until they are printed. One relay client can provide several printers; every printer you share becomes its own destination.

Prerequisites

  • A computer that is switched on when jobs should print: Windows 10 or 11 (64-bit), macOS (Apple silicon or Intel) or Linux (x64 or ARM64). For a NAS or a server with Docker, see Relay client on a NAS or server.
  • The printers are installed on this computer and print from it.
  • Any member can connect their own computer, on every plan. No administrator rights are needed for the installation. The relay client then belongs to the member who confirmed it; admins can manage it too.

One-time setup

1. Download

In the web app, go to Destinations → New destination → Printer on a computer and select Download relay client, or open the download page on the computer that has the printers. The page recommends the right file for your system.

The downloaded file name contains the address of this server, so the program knows where to connect. Download it again from this server rather than passing the file on to another organization.

2. Install and connect

Windows: double-click the downloaded file. It installs the relay client for your user without administrator rights, starts it automatically and opens your browser. If Windows warns about an unknown app, choose "More info" and "Run anyway" (the program is not code-signed yet).

macOS: open Terminal and run the downloaded file once. The download page shows the exact command, for example:

chmod +x ~/Downloads/sealedprint-relay-… && xattr -d com.apple.quarantine ~/Downloads/sealedprint-relay-…; ~/Downloads/sealedprint-relay-…

Linux: run the downloaded file once:

chmod +x ~/Downloads/sealedprint-relay-… && ~/Downloads/sealedprint-relay-…

It installs a systemd user service and shows a link. On a server without a desktop session, run it with sudo and the argument install --system to install a system service instead.

3. Confirm the code

The browser opens the page Connect computer with a code. Sign in if needed, check that the code matches the one shown by the relay client, and select Connect. The page confirms "Computer connected".

4. Share printers

  1. In the web app, go to Destinations → Relay clients. The computer is listed with its printers.
  2. Switch on Shared for every printer that should become a destination.

The new destinations appear on the Destinations tab. They belong to you; to let the other members print to them, switch on All members in the Access column (on narrow screens: Share with all members in the menu of the row). See Members and roles.

Shared printers report their capabilities (paper sizes, trays, two-sided, color), so print options fit the printer.

Every time

Nothing to do: the relay client starts with the computer, keeps the connection and updates itself with signed releases. Jobs to its destinations print as soon as they arrive, and the delivery timeline shows each step: "Received by the relay client", "In the computer's print queue", "Sending to the printer", "Delivered".

The relay client has a local status page at http://127.0.0.1:47315 with its connections, printers and version. It can only be opened on the same computer.

Connecting further organizations

One relay client can serve several organizations. Run sealedprint-relay pair (on macOS ~/Library/Application\ Support/SealedPrint/bin/sealedprint-relay pair) and confirm the code in the other organization.

Troubleshooting

  • The computer shows "Disconnected": the computer is off, asleep or offline. Jobs wait and print as soon as it is back.
  • A printer cannot be shared: printers that forward to Sealed Print (for example a Sealed Print printer URL set up on the same computer) are excluded, because that would create a loop.
  • "Code invalid or expired": restart the pairing on the relay client, for example with sealedprint-relay pair.
  • The relay client has not reported any printers yet: wait a few minutes, then check that the printers are installed and visible in the operating system.
  • Remove the relay client: in Relay clients, open the menu of the computer and select Disconnect. On the computer itself, uninstall it under Installed apps (Windows) or with sealedprint-relay uninstall.

What's next