Developer T4T5 used Anthropic’s Claude Opus 5.5 to recreate Satoshi Nakamoto’s Bitcoin Windows executable, matching the preserved file’s SHA-256 hash and every byte. The file, commonly called Bitcoin 0.1.0, was actually version 0.1.1, compiled on January 10, 2009, at 23:16 UTC using Windows XP and MinGW GCC 3.4.5, according to BeInCrypto. No verified copy of the January 8 launch-day executable is known to survive; the reconstruction provides a reproducible record of how the early software was built.