@streamsy/state

Durable State protocol and stream wrappers for Streamsy durable streams.

DurableStateProtocol<S>/DurableStateStream<S> wrap a @streamsy/core StreamProtocolFactory with a typed Durable State layer: schema-validated collections with standards-shaped change messages (insert/update/delete) and control messages (snapshot-start/snapshot-end/reset).

Usage

import { createMemoryStorageAdapter, createStreamProtocol } from "@streamsy/core";
import { createDurableStateProtocol } from "@streamsy/state";
import type { JsonCodec } from "@streamsy/state";

type User = { id: string; name: string };

const userCodec: JsonCodec<User> = {
  encode: (value) => value,
  decode: (value) => value as User,
};

const protocol = createStreamProtocol({
  storage: { adapter: createMemoryStorageAdapter() },
});
const durable = createDurableStateProtocol(protocol, {
  users: { type: "user", schema: userCodec, primaryKey: "id" },
});

const created = await durable.create("state");
if (created.status === "created") {
  await created.stream.state.insert("users", { id: "u1", name: "Alice" });
  await created.stream.state.update("users", { id: "u1", name: "Alicia" });
  await created.stream.state.delete("users", "u1");
}

Schemas accept a JsonCodec or a Standard Schema validator (via @streamsy/json); primaryKey may be a field name or a function.

Exports

• createDurableStateProtocol, DurableStateProtocol, DurableStateStream
• types: DurableStateCollectionDef, DurableStateMessage, ChangeMessage, ControlMessage, and the typed create/get/read result and option types
• re-exports JsonCodec and JsonSchema from @streamsy/json

License

MIT