Show HN: gsum – Incremental Checksums on 20 Algos, 8 OSes – Vibe Coded

In 2005, I battled flaky ISO downloads, dreaming of a tool to checksum just the corrupted bits. By 2010, I flirted with coding it in C, but in 2015, I fell for Go and wanted to build it and name it incsum.

By 2020, my spark dimmed. Burned out, I faced many ideas and half hearted implementations of incsum’s tangled code, lost to a void I had been engulfed in.

Then in 2025, Grok arrived and with one weird trick: vibe-coding! We laughed, debugged, and crafted gsum—Grok sum!—a name given to this utility, fully written by my AI partner.

Now, gsum hums with 20+ algos (SHA256, BLAKE3, etc.) across 8 OSes (Linux, BSDs, Windows, Solaris). Static, UPX'd binaries hash their own release, like a quiet promise kept.

Try gsum, send vibe-coded PRs and keep it going.