spacetimedb-reducers

Use this skill for reducer implementation and transactional server logic.

Core reducer patterns

Reducers are the transactional entrypoints for table mutation. A successful reducer commits all table changes; a thrown exception, returned error, or panic rolls all of them back.

TypeScript reducer shape:

export const create_user = spacetimedb.reducer(
  { name: t.string(), email: t.string() },
  (ctx, { name, email }) => {
    if (name === "") throw new Error("Name cannot be empty");
    ctx.db.user.insert({ id: 0n, name, email });
  },
);

Language-specific signatures: