01 / THESIS
LunarFS is a content-addressed filesystem for agent workspaces. A BLAKE3 CAS stores every blob once. A copy-on-write overlay forks your repo in ~20ms with zero bytes copied. FUSE-mounted paths hydrate lazily on first access, so your agents never wait on disk.
02 / FRICTION
Git worktrees take seconds to set up. When you run dozens of parallel agent branches, that latency compounds and stalls your whole pipeline before a line of real work begins.
Every new worktree duplicates gigabytes of node_modules. Disk fills in minutes. Agent build times balloon because each workspace re-owns a full copy of every dependency it touches.
Keeping workspaces in sync across machines requires manual rsync or brittle watch scripts. A stale file in the wrong place corrupts a run and wastes the entire context window.
Millions of tiny source files crawl on APFS even on fast SSDs. Every install and build adds seconds you pay on every fork, every agent, every run.
03 / WHAT LUNARFS DOES
Content-addressed / BLAKE3
A BLAKE3 content-addressed store deduplicates every blob across all workspaces. Copy-on-write overlay means a fork takes ~20ms and copies zero bytes upfront. Diverged pages materialize only when written.
FUSE / FUSE-T / ProjFS
Workspaces mount via FUSE on macOS and Linux, FUSE-T for macOS kernel extensions, or ProjFS on Windows. Files appear at mount time but bytes are fetched from the CAS only on first read, so mount is instant regardless of repo size.
Per-path ACL / Sync
Workspace state replicates across machines via the CAS layer. Per-path access control restricts exactly which files each agent can read or write, so parallel runs stay in their lane with zero cross-contamination.
04 / THE CLI
CONTENT-ADDRESSED WORKSPACE TOOL
The lunar CLI is the single interface to the LunarFS daemon. Mount a directory once, then fork isolated copy-on-write workspaces in milliseconds. Sync state across machines, manage per-path ACLs, and let agents work in parallel without stepping on each other.
$ lunar ws fork --from HEAD # 20ms, zero bytes copied