OpenChallenges: A FAIR-aligned, centralized platform for crowdsourced challenges in biomedical research.

Open community challenges are critical for benchmarking computational methods in biomedical research, but the landscape is highly fragmented. Currently, over 2,000 challenges exist across a large and fragmented set of platforms, yet no centralized registry exists to index them. To address this, we developed OpenChallenges, a centralized, FAIR (Findable, Accessible, Interoperable, and Reusable)-aligned hub that aggregates and standardizes challenge metadata from diverse sources into a single, searchable registry. By implementing an updated metadata model explicitly mapped to FAIR dimensions, the platform advances challenge discoverability. A metadata completeness scoring framework assigns each challenge one of four tiers (baseline, standard, comprehensive, and gold standard), providing users with a transparent measure of metadata richness and guiding community curation priorities. Built on an open-source, API-driven architecture, OpenChallenges streamlines discovery, enhances visibility, and supports community-driven curation. This resource transforms a fragmented ecosystem into an interconnected knowledge base, advancing transparency in computational biology.