Tutorial: Quick Start

Quick Start

Install jtree

  1. Download the archive for your computer from opowell.github.io/jtree (Windows, macOS on Apple Silicon or Intel, Linux on x86-64 or ARM64, or a portable one for any system with Node.js 22+).

  2. Unpack it. Node.js is included; nothing needs installing.

Start jtree

  1. Run the launcher in the unpacked folder: start.cmd on Windows, start.command on macOS, start.sh on Linux. On macOS, the first time, right-click start.command, choose Open, and confirm.

  2. The admin page opens in your browser, at http://localhost:3000/admin/. If port 3000 is taken, jtree uses the next free one and prints it in the launcher's window.

Start a new session

  1. In the Browse panel, open an app (for example public-goods, in samples/jtree), or a queue. The samples library has 23 experiments, each as a jtree app, an oTree app and a z-Tree treatment.

  2. In the app's panel, press "New session with this app". The Session panel opens in a window of its own, filling the page (the Window menu goes back to what was open before, and the Panels menu opens the others).

  3. Under Participants, set the number of participants and press "Set".

  4. Press "Start".

The admin with a running public goods session: the Session panel, and the Participants panel showing where each participant is

Participants open the address the Session panel shows, http://<this computer's address>:3000/P1 and so on. To try the session on your own, open participants from the Participants panel, or turn Autoplay on. For more, see Running a Session.

Stop jtree

  1. Close the launcher's window (or press Ctrl+C in it).

Run your own experiment

  1. Put your files in the client/apps folder, then use File → Reload apps in the admin (or start jtree again). jtree runs:

    • jtree apps: a .jtt file, or a folder with an app.jtt (see Designing an App);
    • queues: a .jtq file that lists apps to play one after another, an app whose stages are those apps (see Queues);
    • z-Tree treatments and questionnaires: .ztt, .ztq, or z-Tree's text export (see z-Tree treatments);
    • oTree apps and projects: a folder with oTree's __init__.py (or models.py), or a project with its settings.py (see oTree apps).