This contribution presents the GNSS-observation-based European system for earthquake and tsunami risk assessment (“GO-EUREKA”, https://iono-eureka.github.io), that is currently being developed through a cooperation of several research institutes from France, Italy, Norway, Brazil, Japan and Chile. GO-EUREKA will use quasi-continuous observations of ionospheric total electron content (TEC) from ground-based and ship-based GNSS-receivers, to assess earthquake and tsunami related hazards. Its final aim is to improve the existing tsunami early warning systems. The ionosphere is the ionized part of the atmosphere, located between ~60 to ~800 km of altitude. However, despite being high above the surface, it is sensitive to near-surface events. Thus, natural hazards (NH) generate acoustic/gravity waves that propagate upward and trigger atmospheric/ionospheric perturbations which can be further used for estimation of NH parameters. GO-EUREKA performs the following steps: 1) The data are collected and pre-processed by the module ALTRUIST (http://altruist-project.com), which provides in near-real-time the TEC data and the ground motion information; 2) Co-seismic and co-tsunamic ionospheric disturbances (CSID and CTID, respectively) are automatically detected in TEC data series by using algorithms recently developed by our group (e.g., Maletckii &Astafyeva, 2021, doi:10.1038/s41598-021-99906-5; Brissaud&Astafyeva, 2022, doi:10.1093/gji/ggac167; Ravanelli et al., 2024, doi:10.1029/2024RS008016; Fuso et al., 2024, doi:10.1007/s10291-024-01649-z); 3) Additional confirmation of the link between the detected disturbances and an NH event is done either by spatio-temporal analysis, or by a rapid simulation tools; 4) Inversion of NH parameters (under development) is done: 1) inversion of earthquake magnitude will be done from CSIDs detected in the vicinity of epicentral region, and/or 2) tsunami wave heights and velocity of propagation are estimated from CTIDs detected in the far field. These latter steps are currently under development. We will present our recent developments, and we will discuss future directions.