Celld: Self-hosted, distributed Durable Objects

Celld is an open-source, self-hosted implementation of Cloudflare's Durable Objects that uses S3 buckets for coordination and state management instead of relying on vendor infrastructure. The system maintains the Durable Objects programming model—single-threaded objects with persistent storage—while giving users control over placement, failure domains, and operational visibility. By storing ownership records and SQLite state in S3, celld enables faster recovery after node failures and provides transparent, inspectable failure evidence rather than relying on vendor status pages.