# Apero v3.1.0 - Table of Contents > Pure utility library for Elixir - file operations, cryptography, env/config files, retry, cache, and OS/Proc introspection (no shell execution). ## Pages - [Apero](readme.md) - [Apero](readme-es.md) - [MIT License](license.md) ## Modules - [Apero.Cache.ETS](Apero.Cache.ETS.md): ETS-backed cache with TTL support. - Core - [Apero](Apero.md): Apero — Pure utility library for Elixir (no shell execution). - [Apero.Application](Apero.Application.md): OTP application entry point for Apero. - [Apero.Cache](Apero.Cache.md): Unified cache interface — ETS, Redis, Memcached. - [Apero.Cache.Adapter](Apero.Cache.Adapter.md): Behaviour for cache backends. - [Apero.Cache.Supervisor](Apero.Cache.Supervisor.md): Supervisor for cache adapters. - File & Path - [Apero.File](Apero.File.md): File system utilities — file ops, path operations, atomic writes, temp resources, locking. - [Apero.File.IO](Apero.File.IO.md): I/O operations: atomic writes, checksums, temporary resources, file locking. - [Apero.File.Path](Apero.File.Path.md): Path operations: directory checks, glob, copy, move, delete, read, write. - [Apero.File.Tree](Apero.File.Tree.md): ASCII tree generation and printing for file listings. - [Apero.File.Watcher](Apero.File.Watcher.md): File system watcher GenServer. - Security - [Apero.Crypto](Apero.Crypto.md): Cryptographic utilities — hashing, symmetric/asymmetric encryption, KDF. - [Apero.Crypto.Cipher](Apero.Crypto.Cipher.md): Symmetric encryption and streaming cipher utilities. - [Apero.Crypto.Hash](Apero.Crypto.Hash.md): Cryptographic hashing functions. - [Apero.Crypto.Key](Apero.Crypto.Key.md): Key derivation and asymmetric key generation utilities. - [Apero.Crypto.Random](Apero.Crypto.Random.md): Random generation utilities for cryptographic purposes. - Environment - [Apero.Conf](Apero.Conf.md): Configuration file management — unified interface for JSON, YAML and TOML. - [Apero.Env](Apero.Env.md): Environment variable management for Apero. - System - [Apero.OS](Apero.OS.md): Operating system information utilities for Apero (pure-Elixir subset). - [Apero.Proc](Apero.Proc.md): Process and executable utilities for Apero (pure-Elixir subset). - Retry & Cache - [Apero.Retry](Apero.Retry.md): Retry with exponential backoff and optional jitter.