Deno's celld self-hosts Cloudflare Durable Objects, ~10x cheaper
Ryan Dahl's open-source daemon runs your Workers code unchanged on S3 + SQLite — no control plane, no lock-in, a cheap backend for stateful agents.
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Your Workers and Durable Objects, on machines you own
celld is an open-source daemon that runs unmodified Wrangler bundles — the same Workers and Durable Objects JavaScript APIs, no rewrite. Each object becomes its own SQLite database, so apps shard by construction with no central control plane.
The cost math: ~$48 a month vs Cloudflare's ~$415
At 100 resident objects, Cloudflare Durable Objects runs about $415/mo; celld runs on a single ~$48/mo node. Push to 10,000 objects and it's ~$486 vs ~$41,500 — an order of magnitude cheaper, and the gap widens the more you scale.
Durable with no consensus and no membership protocol
Nodes coordinate only through an S3 bucket you own — no Raft, no control plane. State replicates continuously in LTX (Litestream's format); single-region setups hit RPO=0 (no acknowledged write lost), ~90ms writes, and ~20s failover with zero data loss.
Build this weekend: a self-hosted brain for your agents
Durable Objects are the default home for per-session agent state; celld lets you run that backend on your own S3 plus a small box — ~4MB RAM per cell, ~1,000 cells per 8GB node — with zero Cloudflare lock-in. One curl to celld.dev/install.sh gets you going, Apache-2.0.
Elsewhere: Vercel Sandbox scales to 10,000 at once
Vercel raised Sandbox limits for Pro and Enterprise teams to 10,000 concurrent sandboxes and 5,000 vCPUs per minute — enough headroom to fan out a large fleet of coding or browsing agents in parallel.