OPFS

OPFSResource mounts the Origin Private File System as a Mirage resource. Files persist across page reloads but stay scoped to the current origin.

Browser only. There is no OPFS in Node; for local persistence in Node, use Disk.

Install

pnpm add @struktoai/mirage-browser

Config

import { MountMode, OPFSResource, Workspace } from '@struktoai/mirage-browser'

const opfs = new OPFSResource({ root: 'mirage' })

const ws = new Workspace({ '/data': opfs }, { mode: MountMode.WRITE })
await ws.execute('echo persistent | tee /data/note.txt')

Field	Default	Notes
`root`	`''`	Subdirectory under the OPFS root. Useful to namespace multiple workspaces.

Mount mode

read, write, exec.

Storage and quotas

The browser sets per-origin quotas (typically a fraction of free disk, single-digit GB on most setups). Hitting it raises QuotaExceededError.

const { quota, usage } = await navigator.storage.estimate()
console.log(`${usage} / ${quota} bytes`)

For long-lived workspaces, request persistent storage early so the browser doesn’t evict your data under storage pressure:

await navigator.storage.persist()

See TypeScript Limitations: Browser for the full set of browser constraints.

Getting Started

Agents

Resources

CLIs

Watch

Runtimes

Install

Config

Mount mode

Storage and quotas

​Install

​Config

​Mount mode

​Storage and quotas

Install

Config

Mount mode

Storage and quotas