SpacetimeDB

SpacetimeDB collapses the usual backend stack into a single system: the database is also the application server. Instead of running a web service that talks to a database over a network, application logic is uploaded into the database itself as stored procedures called reducers, written in Rust, C#, or TypeScript, and executed at database speed inside strongly serializable ACID transactions. Clients connect directly and receive realtime updates as committed state changes, with no separate API layer, ORM, cache, or message queue in between.

That architecture is the basis of its AI-agent pitch, "let AI ship the whole backend, glue-free." Because there is one type system spanning client, reducer, and schema, and no infrastructure to wire together, there are far fewer places for an agent to misconfigure something or invent a mismatched interface. The homepage ships copy-paste quickstarts for Claude Code, Cursor, and Codex that scaffold a project and hand the agent a working starting point, and the docs demonstrate building a full realtime chat or Discord-style app this way. Client SDKs cover React, Vue, Svelte, Next.js, and Node.

SpacetimeDB is developed by Clockwork Labs, backed by Andreessen Horowitz, Supercell, and the founders of Roblox and Unity, and released under the Business Source License 1.1. Its Maincloud hosting runs a free tier, Pro at $25 per month, Team at $250 per month, and custom Enterprise pricing, with usage metered in a compute unit called TeV across reducer calls, storage, and egress. Self-hosting via Docker is also supported.