Core Survey Analysis Infrastructure R package surveycore version 1.0.0 A modern, 'S7'-based foundation for survey analysis spanning both probability and non-probability samples. Probability sample designs include Taylor series linearization, replicate weights (BRR, Fay, jackknife, bootstrap), and two-phase estimation, following 'Lumley' (2004) <doi:10.18637/jss.v009.i08>. Non-probability sample designs support bootstrap and jackknife variance estimation for opt-in panels and convenience samples. Provides a unified estimator interface for means, frequencies, totals, quantiles, ratios, correlations, regression, and t-tests, with weighted 'polychoric' and 'polyserial' correlation following 'Mannan' (2025) <doi:10.2139/ssrn.6580480>. A metadata system preserves 'haven'-style variable labels, value labels, and question-preface attributes through all operations. Uses a 'tidyselect' interface throughout. Software Depends: R (>= 4.3.0) Imports: S7 (>= 0.1.0), rlang (>= 1.0.0), tidyselect (>= 1.2.0), cli (>= 3.6.0), tibble (>= 3.1.0), dplyr (>= 1.1.0), marginaleffects (>= 0.18.0), pbivnorm (>= 0.6.0), stats, graphics Suggests: testthat (>= 3.0.0), withr (>= 2.5.0), surveytidy (>= 0.5.0), survey (>= 4.0), survival, srvyr (>= 1.0), haven (>= 2.5.0), lifecycle (>= 1.0.0), broom (>= 1.0.0), polycor (>= 0.8.0), jtools (>= 2.2.0), covr, knitr, rmarkdown Jacob Dennen <jdenn0514@gmail.com> Comprehensive R Archive Network (CRAN) Jacob Dennen [aut, cre, cph] (ORCID: <https://orcid.org/0000-0003-3006-7364>), Thomas Lumley [ctb, cph] (Author of variance estimation code vendored from the 'survey' package) GPL (>= 3) 2026-06-08 application/tgz https://CRAN.R-project.org/package=surveycore doi:10.32614/CRAN.package.surveycore