UUID v4 Generator

This tool generates version 4 UUIDs (RFC 4122) for software development, testing, data management, and API integration. Primary users are developers, QA engineers, database admins, and integration engineers who need unique identifiers for records, tokens, test fixtures, and synthetic data. It is used when seeding databases, wiring mock services, or producing stable keys for fixtures and logs. The tool focuses on correctness, formatting consistency, and fast generation. Core problem solved: produce high-entropy, collision-resistant identifiers that conform to the UUID v4 standard and can be produced in batches without external dependencies. Core logic & rules: outputs are lowercase, hyphenated strings in the 8-4-4-4-12 layout. The tool accepts a batch count and returns a single string when count=1 or an array when count>1. Optional advanced features include enabling or disabling strict lowercase output and selecting the number of IDs per request. Assumptions: no seed input is required; randomness relies on a cryptographically secure RNG if available. Exclusions: not intended for use as cryptographic keys, digital signatures, or license tokens; for those needs, use established key management solutions. Inputs & Outputs: Inputs include count (integer, 1–100; sample 5; required), and an optional flag to enforce lowercase formatting (default true). Outputs include ids (string or array of strings) and a simple metadata block with count. Algorithms & Calculations: UUID v4 uses 128 bits; version nibble is set to 4; variant nibble set to 8, 9, a, or b; 122 bits are random. Generation uses cryptographically secure RNG; output formatting enforces the standard dash positions. Error & Edge Cases: invalid count raises INVALID_COUNT; RNG failures raise RNG_FAILURE with a retry or fallback; extremely large batches are rejected; collisions within a batch are statistically improbable. Industry/Region & Localization: RFC 4122 standard; formatting is lowercase with hyphens; no locale-specific variations; suitable for internationalized codebases. Assumptions & Exclusions: no seedable output; not a replacement for security tokens; designed for non-cryptographic use cases where unique identifiers are required in tests and data fixtures.