There are more planets than stars in our Galaxy. The planet formation process must be very widespread and happen under various conditions but it is still not well understood. Observationally, we only have access to its very beginning, when young stars are surrounded by disks of dust and gas, and its very end by detecting and characterizing exoplanets. However, its intermediate stages are not easily observed. Using novel numerical models, the PLANETOIDS project will create an all-inclusive framework including protoplanetary dust growth to the pebble-sized amalgamates, and the creation of planetesimals, the building blocks of planets. Specific focus will be given to planetesimal formation location, time, and number in the accretion disc, as well as influences of the host star. Despite the critical role of this phase in the planet formation process, global models addressing planetesimal formation are scarce. With PLANETOIDS, we will go beyond the state-of-the-art by combining the most advanced models of circumstellar disk formation and structure, dust evolution, planetesimal formation, and planetesimal growth in one comprehensive framework. The key objectives of PLANETOIDS are: 1) investigating how dust grows and circulates in wind-driven circumstellar disks, 2) understanding where, when, and how many planetesimals can emerge and how this result depends on the properties and environment of the host star, 3) exploring the pathways of fast planet formation required to explain the observations of young circumstellar disks. With these developments, it will become possible to self-consistently simulate the decisive early stages of planet formation for the first time. The awaited results are essential for explaining the origin of the Solar System and the diversity of exoplanets.
