A cloud filesystem for platforms and agents.

LoonFS is a fast, scalable filesystem built on object storage. Durable and embeddable by design.

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Features

Familiar primitives and functionality

Filter files...
acme
deal-room
summary.md
model.xlsx
diligence.pdf
research
archive
acme/deal-room/summary.md
1 # Project Atlas — deal summary
2
3 **Stage:** diligence
4 **Close:** Q3 2026
5
6 - [x] NDA countersigned
7 - [ ] [model.xlsx] reviewed

Embeddable, anywhere

Use LoonFS as a personal workspace, share it with your team, or embed it within your platform.

% loon
 Read and write to your LoonFS durable workspace.
 Filesystem operations 
ls List entries at a path. stat Show metadata for a path. cat Print file contents to stdout. get Download a remote file. put Upload a local file. mkdir Create a directory. rm Remove a path. mv Move or rename a path. cp Copy a path.

Familiar and compatible

Features you already know and that "just work" with your evolving workflows and tools.

Version history
v4 Finalize metrics and proof the summary conor@example.com · Just now
v3 Proofread final version charles@example.org · 9 min ago
v2 Rebuild charts from Q3 actuals conor@example.com · 5 hr ago
v1 Create report.md conor@example.com · 8 hr ago

Durable collaboration at scale

Versions, rollbacks, forks, and preconditions — work faster, not looser.

Protocol

Transactional and durable

LoonFS is built around a correctness-first protocol.

Read the docs

Atomic. A multi-file write commits as one unit — it either lands completely or fails safely and leaves the namespace in a valid state.

Isolated. Every query is resolved against an authoritative snapshot; another agent's in-flight writes stay invisible until they commit.

Consistent. Every read resolves against one committed revision, so a path never returns state between successful transactions.

Durable. Content, metadata history, manifests, checkpoints, and control state are stored as LoonFS objects in durable object storage.

Performance

Fast and scalable

Writes (ops/sec)
105.1
37.8
5.20
3.83
Drive
Box
Dropbox
Reads (ops/sec)
1,325.7
486.7
41.8
27.3
Drive
Box
Dropbox
Metadata mutations (ops/sec)
993.7
85.2
73.3
1.36
Drive
Box
Dropbox

Throughput measured against each provider's API on the same benchmark suite. Higher is better.

Architecture

Object storage native

Content and metadata are durably committed directly to object storage, and reads are accelerated using a cache. LoonFS can be run on a server or embedded in-process with a single dependency: an S3-compatible store.

Read the docs
Developer experience

Interfaces purpose-built for developers

CLI

LoonFS is designed to be used and navigated like a native filesystem. All filesystem commands available by default in agent-friendly interfaces.

SDK

Typed clients for TypeScript and Python. The same namespaces, history, and sharing you get from the CLI: a few lines of code, ready to embed in your app or your agent.

Start building on LoonFS.

Use LoonFS in your environment.

Works with most S3-compatible stores including S3, GCS, and R2.