REE (Reproducible Execution Environment) packages model export, compilation, inference, and output decoding into a single containerised pipeline for verifiable AI execution. It supports 40+ models across 20+ GPU targets, covering the RTX 30-, 40-, and 50-series and every generation of data-centre hardware from Volta to Blackwell. Use standard, deterministic, or reproducible modes, generate cryptographic receipts for completed runs, and validate results independently without requiring identical hardware.