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LIGO-Virgo Alert System

The LIGO-Virgo Alert System (LVAlert) is a prototype notification service built on the xmpp (jabber) protocol and the pubsub extension. It provides a basic notification tool which allows multiple producers and consumers of notifications. To use the service, you must first visit the account activation web page to set your LVAlert password. Client tools are provided in LSCSoft to send notifications, to administer subscriptions and nodes in the service, and to listen for notifications. You can read about using the service at the LVAlertHowto page. There is also a page with technical information for administrators.

How it works

An entity publishes information to a node (think of it like a channel). Other entities subscribe to that node (channel) and then listen for content published on the channel. The listener can be configured to take an action upon receipt of an alert.

Example use cases

Sample use case #1: a GRB alert arrives and gets published to the external_swift_grb node, and the CBC and Burst groups each have listeners waiting for the alerts. The CBC group listener is configured to run an inspiral search if the GRB alert indicates either a short GRB or has no duration information. The burst group listener is configured to run an X-Pipeline search for each GRB alert.

Sample use case #2: an entity (person, group or service) publishes a candidate event into the Gravitational Wave Candidate Event Database (GraceDB). The GraceDB service, at the time of receiving the event, sends a notice to the pubsub service. People who are interested in following up such candidates can listen for the notification and take the appropriate action upon receipt of the notification. For example, a sky-localization or parameter estimate job might be carried out.

Project Librarian

Tanner Prestegard <> and Alexander Pace <> are the LVAlert project librarians.


You can read about using the service at the LVAlertHowto page.

You can set or re-set your LVAlert password on the account activation web page.

There is also some documentation for administrators.

Downloading / Installing

Scientific Linux

Follow the instructions on configuring your machine to use the LSCSoft yum repository up to but not including the yum groupinstall. After configuring your yum repository, execute yum install ligo-lvalertand you are done.


Follow the instructions for configuring your machine to use the LSCSoft Debian repository, up to but not including the aptitude install lscsoft-all command. Once this is done, execute aptitude install python-ligo-lvalert to install the LVAlert client package.


The LVAlert client tools are available in MacPorts as ligo-lvalert.

PyPI (the Python Package Index)

The client tools are also available via PyPI: pip install ligo-lvalert

NOTE:I had some trouble installing the client with pip in a virtual environment on El Capitan 10.11.4, with Python 2.7.11. Here is the sequence of steps I used:

        sudo port install py27-pip
        sudo port select --set python python27
        sudo port select --set python2 python27
        sudo port select --set pip pip27
        sudo port install py27-virtualenv
        cd /opt/local/bin
        sudo ln -s /opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin/virtualenv virtualenv
        sudo port install libxml2
        sudo port install py27-libxml2
        sudo port install swig
        sudo port install py27-m2crypto
        cd ~/
        virtualenv --system-site-packages my_virtual_env
        source my_virtual_env/bin/activate
        pip install ligo-lvalert

Tarball / Git Repository

Source tarballs are available on (look for ligo-lvalert-X.Y.tar.gz).

The GraceDB client package is available in the lscsoft group at Note that code at the head of the git repository may be volatile or unstable. One should know what they are doing if using this option.

Once downloaded, installation is the normal python distutils procedure; cd into the source directory and execute python install [--prefix=/TARGET/INSTALLATION/DIRECTORY].

Bug Reporting

Please report bugs using the LVAlert Redmine area.

Mailing Lists

Discussion of the LVAlert software and service should be directed to the DASWG mailing list.


  • Patrick Brady
  • Brian Moe
  • Branson Stephens
  • Kipp Cannon
  • Reed Essick
  • Alexander Pace
  • Tanner Prestegard

-- BransonStephens - 18 Aug 2015

SoftwareProjectsForm edit

Name ligo-lvalert
License GPL-2.0-or-later
Description LIGO/Virgo LVAlert client powered by SleekXMPP
Topic revision: r9 - 2019-05-09,
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