zipcodeR 0.4.0

Reproducibility contract

• Every pre-existing exported function retains the zipcodeR 0.3.5 signature, return value, class, attributes, row order, rounding, warnings, messages, errors, and edge-case behavior. This deliberately includes historical defects where changing them could alter published research.
• The bundled zip_code_db, zcta_crosswalk, and zip_to_cd objects are identical to 0.3.5: 41,877 ZIP rows, 148,897 ZCTA-to-tract rows, and 45,914 ZIP-to-district rows.
• zip_distance() and search_radius() retain the legacy raster::pointDistance() WGS84 calculation. search_radius() now invokes that same calculation in a vectorized call; the differential gate requires exact object identity with 0.3.5 before accepting the speedup.
• Depends: R (>= 3.5.0) and the legacy runtime dependencies are retained. download_zip_data() keeps its prior observable behavior. Documentation, rather than a runtime warning or no-op, discourages its use.

Explicit next-generation API

• The _ng API is the recommended interface for new analyses. Its suffix makes the opt-in visible in code: callers choose newer, versioned data and corrected semantics while existing unsuffixed calls stay historical.
• Corrected behavior and modern data are opt-in through the _ng functions: search_state_ng(), search_county_ng(), search_city_ng(), search_tz_ng(), search_fips_ng(), search_cd_ng(), search_radius_ng(), reverse_zipcode_ng(), geocode_zip_ng(), get_tracts_ng(), get_cd_ng(), is_zcta_ng(), normalize_zip_ng(), and zip_distance_ng().
• Every data-dependent _ng function requires an explicit validated data bundle as its first argument. No lookup resolves a latest alias, consults a global option, mutates the session, falls back to another vintage, or performs an implicit network request.
• _ng never means an unpinned “latest” dataset. A project selects and records one immutable bundle version and checksum.
• download_zip_data_bundle(version), read_zip_data_bundle(path), zip_data_version(x), and zip_data_provenance() support checksum-pinned, offline, and auditable research workflows.
• _ng lookups preserve input order and duplicates, represent missing rows explicitly, validate inputs consistently, use modern geodesic behavior, keep GEOIDs as character identifiers, and expose authoritative/unmapped district status.
• reverse_zipcode_ng() adds the two-digit state FIPS code and full five-digit county FIPS code for the record’s predominant county.
• raster and tidycensus remain installed legacy dependencies, but are no longer imported when zipcodeR starts. They load only when a legacy function actually calls them, avoiding the historical raster/terra and GDAL/Arrow startup failures without changing legacy results.

Versioned data assets

• Refreshed data is no longer substituted into the package defaults. The pipeline writes one external RDS bundle with dataset, metadata, provenance, and quality sidecars, plus a manifest and reproducibility archive.
• Static sources, the raw ACS response, and the derived ACS table are archived and checksummed. GeoNames is pinned rather than floating. The data version and build timestamp are explicit inputs; the full package dependency graph is locked.
• ZIP candidates absent from an authoritative ZCTA source are quarantined. Proxy city points are not published as ZIP centroids. District assignments use the Census relationship file only; USPS-only ZIPs without an authoritative relationship remain unmapped with a reason.
• Upstream inspection and deterministic rebuilds are separate workflow modes. The workflow uploads unpublished candidates for review and never chooses a version or publishes automatically.
• Refresh candidates are accepted only after their requested timestamp is representable and every source-archive member can be listed, extracted, and checksum-matched to the staged input.
• The immutable data-2026.09 bundle, manifest, and standalone reproducibility archive are public and are the recommended pinned inputs for new _ng analyses. They use the same reviewed source vintages as data-2026.08, but add the frozen legacy inputs, exact pipeline commit, and Linux amd64 platform to the verified build contract. The comprehensive SQLite asset remains explicitly pinned to data-2026.08; no implicit substitution occurs.

Tests, documentation, and infrastructure

• tools/compatibility-check.R installs 0.3.5 and the candidate in isolated libraries, then compares the public datasets, legacy calls, conditions, and function signatures with identical().
• Independent tests cover bundle schema/checksum failures, cache corruption, explicit version handling, _ng order/duplicate/missing behavior, antimeridian and threshold searches, unavailable coordinates, and authoritative/unmapped district behavior.
• CI runs ordinary vignette-building R CMD check --as-cran on Windows, macOS, Ubuntu release/devel/oldrel and runs the differential gate. The Windows SHA fallback ignores non-portable shasum.bat wrappers.
• A migration vignette documents unchanged legacy calls, explicit bundle pinning, _ng calls, and recording both data version and bundle SHA in research outputs.
• inst/CITATION uses bibentry() rather than deprecated citEntry().

zipcodeR 0.3.5

• Hotfix to address a failing vignette and prevent archival by CRAN.

zipcodeR 0.3.4

• Fixed ordering of zip_distance() results (contributed by Nicholas X Lee).

zipcodeR 0.3.3

• Vectorized zip_distance() across two vectors or columns of ZIP codes.
• Added the units argument to return miles or meters.

zipcodeR 0.3.2

• Updated zip_code_db.
• Refactored download_zip_data() to download directly from upstream.
• Added the lonlat distance-calculation argument.
• Added package citation data.

zipcodeR 0.3.1

• Removed the {udunits2} dependency from distance and radius functions.

zipcodeR 0.3.0

• Added search_radius(), zip_distance(), geocode_zip(), and normalize_zip().
• Updated reverse_zipcode() to return a blank row for unmatched ZIP codes.
• Made the search_ family quieter.

zipcodeR 0.2.0

• Added approximate county matching, vectorized state/timezone searches, reverse lookup, congressional-district helpers, ZCTA testing, and FIPS searches.
• Updated the ZIP database and added the introductory vignette.

zipcodeR 0.1.0

• Initial CRAN release.