OMP is a fork of Pi that grew five times larger than its parent and changed almost every architectural decision. Pi's loop is 796 lines; OMP's is 2,935. Pi has zero Rust; OMP has 145,000 lines of it. Pi presents one uniform 7-tool surface; OMP computes a different surface per model, per session, per capability probe.
The signature invention is hashline: an edit language where every section is anchored to a 16-bit hash of the whole file, minted by the read that produced the line numbers. The body carries only new content — no retyped context, no -old lines. It tracks which lines the model actually saw and refuses edits over elided regions, and on drift it tries a provably-safe line remap before failing closed.
Underneath, a vendored bash engine runs as a persistent in-process shell and about 58 CLI utilities (grep, sed, jq, fd, ls, xargs, ps, top…) are Rust modules resolved without fork/exec — on macOS, Linux and Windows without WSL. Search, glob, diff, PDF, PTY, syntax highlighting, tokenization and copy-on-write filesystem isolation are all native too.
It also ships things nothing else here has: a real DAP debugger across 14 adapters, persistent REPL kernels for Python/JS/Ruby/Julia that can call back into the agent's own tools, Chromium automation plus host desktop control, and snapcompact — compaction that rasterises discarded history into bitmap-font PNGs for vision models instead of paying for a summary call.