Dead-simple password hashing with Argon2id — hash() and verify(), nothing more
Ergonomic CLI binary integration testing with fluent assertions on stdout, stderr, and exit code
Micro-benchmarking utilities with statistical analysis, comparison, and regression detection
Human-readable byte size formatting and parsing
Generic LRU cache with TTL, tags, and async support for Rust
Programmatic CHANGELOG.md parsing, generation, and manipulation following Keep a Changelog format
Cross-platform terminal color and style output with automatic capability detection
Color manipulation library — parsing, conversion, blending, contrast checking, and ANSI terminal output
Layered configuration from files and environment variables
Cron expression parsing, scheduling, and human-readable descriptions
High-level CSV reading, writing, and manipulation
Date and time utilities — business days, date ranges, holiday calendars, and formatting shortcuts
Better test assertion diffs with colored inline comparisons
Fast .env file parser with variable interpolation, multi-file layering, and type-safe loading
Human-readable duration formatting and parsing
RFC 5322 compliant email address parsing, validation, and normalization
Typed environment variable validation with batch error reporting for Rust
Thread-safe event bus with typed listeners for Rust
In-memory feature flag evaluation with rollout, environment, targeting, and A/B variant support for Rust
Early-return guard clause macros for cleaner control flow
HTTP health check client for monitoring service dependencies with configurable thresholds
Declarative HTTP API integration testing framework with fluent assertions
Unified ID generation: ULID, UUIDv7, NanoID, and Snowflake
IP address utilities — CIDR matching, subnet calculation, classification, and anonymization
Structural JSON diff with path tracking for Rust
JSON Web Token encoding, decoding, and validation with HMAC algorithms
Data masking and redaction for strings, emails, and sensitive data
File type detection from content (magic bytes), file extension, and MIME type mapping
Lightweight, per-test HTTP mock server for testing API integrations
Easy parallel iteration — par_map, par_filter, par_for_each with progress and error collection
Token bucket, sliding window, and fixed window rate limiting
Extension traits for Result and Option with tap, map, and error accumulation
Async retry with exponential backoff and circuit breaker for Rust
Graceful shutdown coordination with timeout support for Rust
Secure in-memory secret storage with automatic zeroization, expiry, and redacted display
Semantic versioning with range parsing, comparison, and bumping
Service health checker with liveness and readiness probes for Rust
Unicode-aware slug generation for URL-safe strings
String manipulation utilities — truncation, case conversion, padding, and whitespace operations
Terminal table rendering with alignment, borders, Unicode support, and ANSI color awareness
In-process thread-based task queue with priority and concurrency control
Lightweight string template engine with variables, conditionals, and loops
Strongly-typed HTTP header parsing and construction for common headers
HMAC-SHA256 webhook signing and verification for Rust