Virtual filesystem and pluggable runtimes for AI agents

Cloudflare Computer is a virtual filesystem that lives inside a Durable Object. It keeps authoritative state in SQLite and exposes a pluggable execution surface through workspace.runtime, giving AI agents a unified working directory and runtime environment. The project is currently a preview, good for prototyping, not for production.

AI agents often need to read and write files, run shell commands, or execute JavaScript across different environments—containers, Workers, local machines—each with its own quirks and state-sync pain. Cloudflare Computer consolidates all file state into a Durable Object's SQLite, then dispatches execution to different backends through a single workspace.runtime.exec entry point. Backends connect lazily on first use, so there is one source of truth and no second store or sync round-trip.

Three backends ship with the repo. The container backend projects SQLite state into a sandbox container as a real FUSE mount; a daemon called computerd syncs changes back over a capnweb RPC channel, giving you a full Linux userland, real binaries, and real network. The Isolate shell runs just-bash inside a Dynamic Worker and reaches the authoritative Workspace over Workers RPC, so there is no second store or sync round trip. The Isolate JavaScript backend evaluates an ECMAScript module in a fresh Dynamic Worker, with structured input/results, durable relative imports, configured libraries, Workspace-backed node:fs/promises, and trusted ws:git and ws:artifacts modules. You can also register custom backends under stable IDs, or construct a Workspace with no backend at all and use it purely as a filesystem.

The repo is a small monorepo, with each package carrying its own README. @cloudflare/dofs provides the Durable Object SQLite-backed virtual filesystem and sync protocol building blocks; @cloudflare/computer-rpc defines the capnweb wire types plus server/client helpers; @cloudflare/computerd is the daemon that mounts FUSE and serves HTTP/WebSocket RPC inside the sandbox container; @cloudflare/computer is the top-level package consumed by Durable Objects, still a work in progress. There is also a private Docker image context that publishes the prebuilt computerd linux-x64 binary.

To get started, install @cloudflare/computer and follow that package's README—it has installation steps, the entrypoint map, and worked examples for the fs and runtime surfaces. The examples/ directory contains runnable consumers: the container example runs computerd inside a container, mounts a workspace, and talks to the Durable Object over capnweb; worker-shell runs just-bash in a Dynamic Worker; worker-javascript evaluates an ECMAScript module instead. There are also a think chat agent that uses the workspace as its working directory, a web UI that compares container vs worker runtimes side by side, a step-by-step tutorial that generates a markdown recipe and runs pandoc to produce a PDF, an artifacts example that publishes a Worker project to Cloudflare Artifacts, and an assets example that turns a prompt into an image via Workers AI and returns a shareable link.

This package is provided as a preview for feedback only. APIs are unstable and the design is subject to change; docs/ is forward-looking, so read it for intent rather than as a description of the current code. It is suitable for experiments, exploration, and prototypes—not for production. On performance, computerd's FUSE mount beats real disk on metadata-heavy work but trails on large sequential I/O; see docs/19_performance.md for full fs-bench numbers. Also note that the repo accepts bug reports, fix proposals, and feature requests via issues and discussions, but does not accept unsolicited pull requests.