Real-time File Monitoring in Containers

Cloudflare has introduced real-time file watching capabilities to Sandboxes, enabling developers to monitor filesystem changes as they happen inside containers. The new sandbox.watch() method returns a Server-Sent Events stream backed by native inotify, providing a low-level, efficient mechanism for tracking file modifications.

API and Usage

The sandbox.watch(path, options) method accepts a directory path and optional configuration:

• Path: The directory to monitor
• Recursive: Watch subdirectories (defaults to false)
• Include: Glob patterns to filter events (omit to receive all events)

Each event includes a type field (create, modify, delete, or move) and the affected path. Move events additionally include a from field with the original path.

Integration Patterns

Developers can consume the stream in two ways:

Browser streaming: Return the stream directly as a Response with Content-Type: text/event-stream to send real-time updates to clients.

Server-side consumption: Use the parseSSEStream utility to iterate over events within a Worker without forwarding them to clients, enabling programmatic handling of filesystem changes.

Getting Started

Update to the latest version with npm i @cloudflare/sandbox@latest. Full API documentation is available in the Sandbox file watching reference.