The 35th annual conference on Astronomical Data Analysis Software & Systems 2025 in Görlitz, Germany

The growing volume of alerts from time-domain and multi-messenger astronomy, often with poor localization, necessitates automated and optimized follow-up scheduling. We present tilepy, an open-source Python package designed to meet this challenge by automatically generating efficient observation plans.
tilepy processes HEALPix-based sky maps to derive pointing schedules using various strategies, from 2D probability integration to 3D methods that exploit distance estimates to correlate event localization with galaxy catalogs. Its scheduling engine is highly flexible, handling complex operational constraints for both ground-based (e.g., zenith limits, sky brightness) and space-based observatories (e.g., occultations, SAA passage). The framework also handles diverse and non-circular FoV shapes, including rotation, to accurately model various instrument footprints.

Designed for broad integration, tilepy is available as a public package on GitHub and PyPI, accessible via a cloud-based REST API at tilepy.com, and is seamlessly integrated into the Astro-COLIBRI multi-messenger platform for user-friendly web and mobile access. The framework is in operational use by major collaborations like H.E.S.S. and CTAO/LST-1, providing a robust and accessible solution for efficient transient follow-up.