golf

Time-series data often outgrows the database that collected it: you need fast range reads over immutable history without operational overhead. golf is a binary file format for exactly that — append timestamped records with small fixed-size values, seal the file once, then read ranges through a binary-searched block index at O(log B + log N), with per-block LZ4/Zstd decompression and CRC32C integrity checks.

It's spec-first: SPEC.md pins the layout byte-by-byte, and shared fixtures drive compatibility suites across four native implementations — Rust (the reference), Go, Python, and TypeScript.