This package provides functions to query (filter or transform), pivot (convert from array-of-objects to object-of-arrays, for easy import as R data frame), search, patch (edit), and validate (against JSON Schema') JSON and NDJSON strings, files, or URLs. Query and pivot support JSONpointer', JSONpath or JMESpath expressions. The implementation uses the jsoncons <https://danielaparker.github.io/jsoncons/> header-only library; the library is easily linked to other packages for direct access to C++ functionality not implemented here.