A developer operating under the alias T4T5 has successfully reconstructed the original Bitcoin executable file from 2009. By utilizing Anthropic’s Claude Opus 5.5, the developer managed to recreate the exact development environment used by Satoshi Nakamoto, resulting in a bitcoin.exe file that matches the original SHA-256 hash byte-for-byte.
The reconstruction process required assembling a specific software environment using packages from 2006 to 2008. The investigation revealed that Satoshi Nakamoto worked on Windows XP, utilized the MinGW GCC 3.4.5 compiler, and applied maximum optimization specifically to the mining hashing code while keeping the rest of the software in debug mode.
The study clarified that the widely known Bitcoin 0.1.0 version is actually 0.1.1, which was compiled on January 10, 2009, at 23:16 UTC. This date is two days after the public announcement of the cryptocurrency. To date, no verified copy of the original executable from the January 8 launch day has been recovered.
While the reconstruction confirms that the preserved 2009 software aligns with the published source code without hidden elements, the search for the initial launch-day program remains ongoing. This project provides historians with a reproducible record of early development practices, though it does not impact current network security.
