Core idea and relation of Gammapy to different γ-ray instruments and the gamma astro data format (GADF). The top left shows the group of current and future pointing instruments based on the imaging atmospheric Cherenkov technique (IACT). This includes instruments such as the Cherenkov telescope array observatory (CTAO), the high energy stereoscopic system (H.E.S.S.), the major atmospheric gamma imaging Cherenkov telescopes (MAGIC), and the very energetic radiation imaging telescope array system (VERITAS). The lower left shows the group of all-sky instruments such as the Fermi large area telescope (Fermi-LAT) and the high altitude water Cherenkov observatory (HAWC). The calibrated data of all those instruments can be converted and stored into the common GADF data format, which Gammapy can read. The Gammapy package is a community-developed project that provides a common interface to the data and analysis of all these γ-ray instruments, allowing users to easily combine data from different instruments and perform joint analyses. Gammapy is built on the scientific Python ecosystem, and the required dependencies are shown below the Gammapy logo.