Motivation:The NHGRI Catalog of Published Genome-Wide Association Studies (GWAS) Catalog has collected, curated, and made available data from over 3 900 studies. The recently developed GWAS Catalog REST API is the only method allowing programmatic access to this resource. Results: Here, we describe gwasrapidd, an R package that provides a client interface to the GWAS Catalog REST API, representing an important software counterpart to the server-side component. gwasrapidd enables users to quickly retrieve, filter and integrate data with comprehensive bioinformatics analysis tools, which is particularly critical for those looking into functional characterisation of risk loci. Availability: gwasrapidd is freely available under an MIT License, and can be accessed from https://github.com/ramiromagno/gwasrapidd. 130 possibility in gwasrapidd, we map EFO identifiers (efo id) to EFO traits with 131 get traits() using the former as a search parameter. The table traits of the S4 132 object traits contains the trait column, providing a one-to-one mapping between each 133 EFO identifier and its trait description (trait). Then, we use internally 134 get variants() to search by EFO trait description (efo trait). 135 Finally, gwasrapidd also provides a set of helper functions to easily browse linked 136 web resources, such as PubMed [11] , dbSNP [12],and GTEx project [13]. 137 Limitations 138The most popular method of access to the Catalog is still the web graphical user 139 interface (GUI), and is therefore still the one that gets more attention and dedication 140 from the GWAS Catalog team. Thus, compared to the web GUI, the REST API is still 141 lagging behind in functionality. Here we discuss some of the limitations of the REST 142 API compared to the web GUI.
143When searching by publication related information, with the REST API, we can 144 only use the PubMed identifier as a query. Thus, to search using other publication 145 related criteria, such as words in the title or date of publication, one needs to download 146 6/9