RFC 6902 JSON Patch and RFC 6901 JSON Pointer: apply, generate, and validate patches with zero dependencies

Rule-string validation engine (\"required|number|min:18\"), nested object schemas, array item validation, custom rules, and full error collection with field paths. Zero runtime dependencies.

Relative time formatting: diff(a, b) -> '3 days ago', configurable thresholds, duration breakdown, Intl.RelativeTimeFormat

Complete HTTP status code reference with IANA registry data, lookup utilities, and category helpers

Health check registry with timeout per check, critical flag, and express handler

In-memory analytics: groupBy with multi-key aggregations, having filters, and pivot helper

GraphQL operation guard for a supplied AST: fragment-aware depth limit with cycle guard, per-field complexity scoring, operation allowlist/denylist, and introspection blocking. graphql-js is optional — accepts its document shape structurally, zero hard dependencies.

Zero-dependency glob matching: **, braces, classes, negation, dotfile policy, compile() and .gitignore-style matchList()

Zero-dependency fuzzy string matching: Levenshtein, Damerau-Levenshtein, Jaro-Winkler, token-set ratio, bestMatch/rankMatches

Full-text search indexing and querying capabilities