CART connector
Connect professional CART stenography software to Line 21 through the desktop app, so human captioners can deliver real-time captions to every destination.
Who is it for?
If you are a professional stenographer, you are likely using dedicated CART software.
The Line 21 App allows you to connect these applications directly to Line 21 in order to produce real-time captions.
While you can still use our Writer web page to create captions, the desktop application offers several advantages. For example, it continues working even when the app is not in focus.
Project Settings
Open the app, enter your Project Code, and click on Connector.

Choose the language you want to caption in, and then select the protocol used by your CART software.
We currently support Eclipse and Catalyst.
Catalyst support is still in beta, so you may encounter some issues. If you do, please report them so we can improve compatibility.
TCP/IP Method
Both supported protocols use TCP/IP as the connection method.
After starting the server in the Line 21 App, configure your CART software to send its output to the same TCP/IP port.
Once the connection is established, the Line 21 App will display a status indicator confirming that your software is connected.
App Overview
The Line 21 desktop app for Windows, macOS and Linux: ingest audio from your computer, connect CART software, and show captions in a customisable overlay.
Overlay
Use the Line 21 App's transparent overlay window to show live captions on screen over other content, including burned-in captions for live events and streams.