JSON EOF Decoder

This tool validates JSON syntax and detects end-of-file issues in a given payload. It is designed for developers, API testers, and data engineers who rely on clean JSON in integration points and data pipelines. It parses the input strictly according to RFC 8259, reports exact error locations (line, column, offset), and flags any trailing data after a complete value. Conceptually the tool builds a parse tree from the input, then checks that the input ends exactly at the end of a single JSON value. Optional modes can relax non-standard constructs like comments, enabling broader compatibility when needed. The core differentiator is precise end-of-input reporting combined with consumed-length metrics, which support reproducible debugging and automated validation in CI workflows. Core features include strict validation, trailing-data detection, detailed error metadata, and a clear parsed output when valid. Typical use cases are API response verification, log ingestion sanitization, and data-pipeline preflight checks. The tool is intended for engineers who require deterministic JSON parsing behavior and robust error reporting to minimize downstream failures.