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Getting Started
This guide walks through installing Courier, enrolling your first computer and sending a first notice. Take it slowly the first time and try it on one computer before you use it on more.
Where Courier is today. Courier is new.
- Seen working on real computers (a lab server and PC, October 2026): a notice sent to a computer and to a person, shown on screen and acknowledged, each step recorded in the console; a notice that waits while nobody is signed in, and one that expires while the computer is off; Active Directory groups read from a real domain; the server and the computer restarting; upgrading, uninstalling and reinstalling with the data kept.
- Not yet proven on real machines: one person signed in on two computers, signing out and another person signing in, a locked or signed-out screen, and automatic updates.
- Known issue: a notice waiting for someone to sign in may not appear when they do. Send it again. It's being fixed in the RSJ Agent.
- Not for emergencies. Courier makes no promise that a notice reaches or interrupts anyone in time. Do not rely on it for a lockdown, a fire alarm or anything where a missed message is dangerous.
- A 64-bit Windows computer that stays on, normally a Windows Server, for Courier itself. Administrator rights to install it. Python is bundled in the installer, so there is nothing else to install on the server first.
- The RSJ Agent on each computer that should show notices. Courier shows notices through it, and Courier's installer carries it: the console makes a deploy script that installs the agent on a computer and enrols it with your Courier server in one step, by hand, as a Group Policy startup script, or with your deployment tool. If you already run Groundskeeper or Caretaker, the agent is already on your computers and only needs enrolling with Courier.
- Network: your computers must be able to reach the Courier server on TCP port 8445 (HTTPS). Nothing needs to be reachable from the internet.
Download the latest CourierSetup.exe from the Releases page. That one
installer is all you need on the server: the Courier module that the RSJ Agent runs on each computer is inside it, and your
Courier server hands it to each computer. The two Source code links GitHub shows on every release hold only the repository's
README and security policy, not the product.
Each release lists a SHA-256 checksum for the installer. To check your download, run
Get-FileHash .\CourierSetup.exe in PowerShell and compare.
Run CourierSetup.exe on the server and approve the administrator prompt.
What to expect: two prompts that are normal. The installer should name RSJ Software Ltd as its publisher. While that publisher is new, Windows SmartScreen may still show "Windows protected your PC": click More info, check the publisher, then Run anyway. If the publisher shows as unknown, do not run it -- tell us in an Issue.
The installer asks one question: whether to allow the RSJ Agents on your computers to reach Courier through the Windows Firewall (inbound TCP 8445). It is ticked by default. If you manage the firewall by Group Policy, untick it and open that port yourself. It can also add a desktop shortcut, which is off by default.
When it finishes, Courier is running as the Courier Windows service (as Local Service, started automatically). Your accounts,
history and settings live in C:\ProgramData\RSJ Software\Courier\Data, apart from the program files, so an upgrade or an
uninstall does not remove them.
On the server itself, choose Courier -> Open Console from the Start menu. It opens https://localhost:8445.
- Your browser will warn that the connection is not trusted. This is expected: Courier makes its own certificate for HTTPS, and on a self-hosted server on your own network that is normal. Choose to continue.
- The page offers Create admin account. Enter a username, a display name and a password of at least ten characters, twice. This can only be done on the server itself, and only while Courier has no accounts. There is no default password.
You are signed in straight away. The console opens from the server only: other computers cannot open it, by design. Only the RSJ Agents on your computers talk to Courier over the network.
If every account is ever lost, run Courier.exe --setup-admin from an elevated prompt in the program folder on the server.
That is for recovery only, and it refuses to replace an account that exists.
- In the console, open Agent Settings (under Configuration, on the Deploy tab) and find Deploy the RSJ Agent. Enter the server's name as your computers reach it and choose Download deploy script. The script contains your server's connection secret: keep it private and delete it when you are done.
- Copy it to the computer and run it from an elevated Windows PowerShell window:
powershell.exe -ExecutionPolicy Bypass -File .\Deploy-RSJAgent-Courier.ps1. It downloads the RSJ Agent from your Courier server, checks it is exactly the build the server holds, installs it and enrols it. If a newer RSJ Agent is already there, it is kept and only enrolled. Run again on a computer already enrolled with this server, it installs nothing; it only starts the RSJ Agent's service if that had stopped. - For many computers, add the same script as a Group Policy computer startup script (the Deploy tab shows the steps), or run it with your deployment tool.
Already have the RSJ Agent from Groundskeeper or Caretaker? Enrol-Courier.ps1 (in the Courier program folder) adds Courier to it
without reinstalling, as before.
The computer appears under Agent Settings, Devices, Registered shortly afterwards. Do this on one computer first.
A computer shows notices only once it has the Courier module. On Agent Settings, on the Courier module tab, tick the computer and choose Enable on selected (or Enable on all enrolled computers). The computer collects the module at its next check-in -- about a minute -- installs it, and the card then shows Installed. The agent's other modules are not touched. Remove Courier on the same tab takes the module off a computer again.
- Open New notice.
- Under Send to, leave Computers selected and tick your computer. (Or choose Send a notice beside it on Agent Settings, Devices, Registered, which ticks it for you.)
- Give the notice a title and a message, and leave Expires after at one hour.
- Choose Preview.... Check how the notice will look, who it reaches and when it closes, then choose the Send button at the bottom of the preview (its label says how many computers it goes to).
- You land on the notice's Results page. On the computer, the notice appears in its own window; the person acknowledges it to close it. Results shows each step as it happens.
The Sending a notice page explains everything on that form, and Audiences explains sending to people.
Under General Settings -> Users, administrators add accounts. There are two roles. An administrator can send notices, sees everyone's history, and manages users, templates, the school name and logo, retention and the directory. A sender sees their own history only, and can send only to the audiences an administrator gives them. Courier will not let you remove the last administrator.
Run the newer CourierSetup.exe over the existing install. It stops the Courier service, replaces the program files and starts
it again; your data folder is not touched. Take a copy of the data folder first, with the Courier service stopped, as you would before any upgrade. (The Updates tab in Settings belongs to Courier's private preview
channel and is not the way to update from a public release yet.)
Use Courier -> Uninstall Courier in the Start menu. It removes the service and the firewall rule it made, and leaves the data folder in place; delete that yourself if you want the history gone.