Query the FDA Global Substance Registration System (GSRS) API R package rgsrs version 0.1.0 Provides functions to query the FDA Global Substance Registration System (GSRS) REST API (<https://gsrs.ncats.nih.gov/api/v1/>). Enables programmatic access to substance records, UNII identifiers, synonyms, external codes, and chemical structures for over 170,000 registered substances. Software Depends: R (>= 4.1) Imports: cli, httr2, janitor, pingr Suggests: fs, openxlsx, spelling, testthat (>= 3.0.0), withr Claudio Zanettini <claudio.zanettini@gmail.com> Comprehensive R Archive Network (CRAN) Claudio Zanettini [aut, cre] (ORCID: <https://orcid.org/0000-0001-5043-8033>) MIT + file LICENSE (https://CRAN.R-project.org/package=rgsrs/LICENSE) 2026-05-05 application/tgz https://CRAN.R-project.org/package=rgsrs doi:10.32614/CRAN.package.rgsrs en-US