celld — Summary

celld is an open-source daemon (Rust, Apache 2.0) that runs Cloudflare Workers and Durable Objects on your own infrastructure. Each Durable Object is its own SQLite database, continuously replicated to an S3-compatible bucket you own. Nodes coordinate through that bucket alone using object-storage Compare-And-Swap — no control plane, no consensus protocol, no leader election.

The architecture has three crates: celld (the executable — V8 runtime, HTTP server, S3 client, alarm/wake system), celld-logic (a pure, deterministic state machine with zero dependencies that makes every lifecycle decision), and celld-ltx (a vendored Rust port of Litestream for SQLite WAL replication to object storage). The boundary between logic and execution is absolute: the logic crate has no async, no I/O, no clocks, and no randomness, making the entire system replayable and testable under deterministic simulation.

Every cell write is fenced by an output gate: the HTTP response is held until the replicator proves the write durable (RPO=0), so celld never acknowledges a write it could lose. Idle cells hibernate to near-zero cost, with SQLite snapshots stored in the bucket for cold restart. Peer-to-peer requests are HMAC-authenticated and replay-protected; TLS is deliberately excluded from the peer protocol, with the design calling for a private network or encrypted overlay instead.

The project is in alpha (v0.1.0). Pull requests are disabled; contributions arrive via git format-patch email to the maintainer.