celld

celld is an open-source daemon that runs a Cloudflare Workers application on your own machines, covering Workers, Durable Objects, KV, Queues, D1, R2, Workflows, Cron Triggers, and static assets, deployed straight from an existing wrangler configuration file. Each stateful object is a cell, a named server with its own SQLite database, and long-term state is stored in an S3-compatible, Google Cloud Storage, or Azure Blob Storage bucket, so an inactive cell costs almost nothing and no separate control plane or consensus service is needed.

One celld process, called a node, runs per machine, embedding V8 to execute Wrangler bundles; nodes sharing one bucket form a fleet, and a conditional write to that bucket gives exactly one node ownership of a cell at a time. Every committed SQLite write is captured in a replication format and proven durable either by uploading it to the bucket, on a single node, or by first replicating it to one or two peer nodes for a faster commit on a multi-node fleet; a takeover recovers a cell's open log from its prior owner before restoring it.