LayerFS

Ephemeral Workspaces. Durable Shared History.

LayerFS is the substrate under your agents. Each one mounts a complete, writable Workspace over shared committed history, does its work, commits what it changed, and goes away.

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layerfs-v1.0.0-release-720p.mp4

Status: LayerFS 1.0.0, the first official release after the 0.1.x Developer Previews, released as source. The results below ran on main at e5c7aaae05. The Store runs in its Disposable profile only, with no crash or power-loss durability: use LayerFS for agent work and its history, not as the only copy of data you cannot rebuild.

Try it with LayerFS × DSH

LayerFS runs today through LayerFS × DSH, the dsh-layerfs plugin for DeepSeek Harness. Agents in a dsh session fork Branches, test them in Sandboxes, merge and publish, and the Work and History tabs show every agent's Branch, live.

Core ideas

01 · Ephemeral Computing Compute exists only while a command runs.	02 · Decentralized Agents Agents on different computers share one serverless Store.	03 · Multiagent Coordination One project, many Branches. One Branch, many agents.
04 · Recursive Filesystem Fork recursively any Commit, at any depth.	05 · Ultra Storage Optimization 157 snapshots of a real project in 100 MB, 19.9× smaller than Btrfs + zstd.	06 · Instant Bootstrap Dependencies come with every mount. No time lost reinstalling.

And underneath them

	Supporting idea	In one line
	07 · Auto Checkpoints	Every step an agent takes is a checkpoint to return to.
	08 · Append-only Objects	Saved objects are never rewritten. The Store only grows.
	09 · Conflict Rules (.lww)	Name the files that should never conflict. The newest edit wins.
	10 · Big File, Small Edit	An edit costs the size of the edit, not the size of the file.

See it run

_{Agents fork Branches, work in Workspaces inside Sandboxes, commit, merge and publish to main. The history grows as they go.}

Results

Every suite ran once on main at e5c7aaae05 through the JavaScript SDK. Each row links to its method, environment and receipts.

Suite	What it measures	LayerFS 1.0.0
fs-bench	Cloudflare Computer's own twelve-scenario filesystem benchmark, unchanged, same image	5.20 s vs 8.88 s, 1.71× faster; faster in 10 of 12 scenarios
dsh-dedup	A real project's history, 157 snapshots (4.94 GB of trees), kept as mountable Commits	100.1 MB vs 1,994.6 MB, 19.9× smaller than Btrfs + zstd; 156/156 read back
pjdfstest	POSIX conformance, 8,798 assertions, against kernel overlayfs	0 unexpected failures; keeps 76% of overlayfs's passes, every other failure a deliberate format limit
fsx	Random reads, writes, mapped I/O and truncates, every byte checked	14/14 pass, 3.06 M ops, 0 miscompares
fsstress	Four concurrent processes, then Commit, remount and compare	3,755/3,755 entries identical; 5.21 GB captured by one Commit in 4.9 s
smallfile	100,000 files of 4 KiB, four threads, against libfuse passthrough	Faster in 9 of 9 operations, 1.27×–10.71×
mdtest	Metadata create, rename and remove, against libfuse passthrough	0.86–1.28× with 1 process, 1.21–4.22× with 4
fio	Data I/O bandwidth, against libfuse passthrough	Random read/write mixes 1.49–2.23×; slower on sequential write (0.31×), sequential read (0.81×) and random write (0.40×)

_{One sample per case, seed 1, no best-of. Host: arm64 Mac, Docker Desktop linux/arm64, 8 CPUs, 8.3 GB; host load is recorded per suite. These are release measurements, not a guarantee for your workload. Earlier fs-bench-pro results: v0.1.4 · v0.1.5 · v0.1.6.}

How it works

agent tool call
 ├─ file tool (read, write, edit, grep …) ── SDK, in process ──────► Store
 └─ Bash ── mount ─► exec ─► commit ─► unmount                       ▲
             └─ Workspace: FUSE view in a Sandbox's daemon ───────────┘
                (committed root + its own overlay)

• Store. One SQLite file holds every Branch, Commit and content object. Each daemon and SDK process opens it directly; there is no database server.
• Branch, Commit, Layer. A Branch is a writable line of Commits. Publishing a Branch to main adds a Layer. Content is chunked and stored once.
• Workspace. A mount binds the whole committed tree without copying it. Writes go to the Workspace's own overlay until a Commit saves them. Unmount deletes the overlay, never history.
• Conflict. Two Commits that change the same file are refused with Conflict, unless a .lww rule says the newest edit wins.

Learn more

Docs	LayerFS × DSH guide · layerfs.ai/docs · Core ideas · JavaScript SDK guide
Concepts	Core concepts · Documentation index
Benchmarks	layerfs.ai/benchmarks
Release	1.0.0 plan · Previous: 0.1.7 release record and its manual

Community

Questions, ideas and show-and-tell are welcome in either place.

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License

LayerFS is licensed under the MIT License.