GraceDB Overview

The Gravitational-Wave Candidate Event Database (GraceDB) is a service operated by the LIGO Scientific Collaboration. It provides a centralized location for aggregating and retrieving information about candidate gravitational-wave events. GraceDB provides an API for programmatic access, and a client package is available for interacting with the API.

Useful information

  • Information about GW alerts and real-time data products is available in the LIGO/Virgo Public Alert Guide.
  • Real-time status of the LIGO Data Grid.
  • Need help? Send an email to, or LIGO/Virgo users can report issues on the GraceDB Gitlab page.

  • Testing Instance

    This GraceDB instance is designed for Quality Assurance (QA) testing and validation for GraceDB and electromagnetic follow-up (EMFollow) developers. Software should meet QA milestones on the test instance before being moved to Playground or Production. Note, on this GraceDB instance:

    • Phone alerts (calls/SMS) are enabled
    • Email alerts are enabled
    • igwn-alert messages to kafka:// are enabled
      • Messages are sent to group: gracedb-test
    • Only LIGO logins are provided (no login via InCommon or Google).

    Server code version: 2.21.3