SpacetimeDB Core Concepts SpacetimeDB is a relational database that is also a server. It lets you upload application logic directly into the database via WebAssembly modules, eliminating the traditional web/game server layer entirely. --- Critical Rules 1. Reducers are transactional. They do not return data to callers. Use subscriptions to read data. 2. Reducers must be deterministic. No filesystem, network, timers, or random. All state must come from tables. 3. Read data via tables/subscriptions , not reducer return values. Clients get data through subscribed queries. 4. Auto-increment IDs a…