Postgres Persistence

1START LOOP ----> WRITE INSTANCE (Postgres)
2TRANSITION ----> APPEND HISTORY (Postgres)
3QUERY STATE ---> READ INSTANCE + READ HISTORY

1import { createLoopSystem } from "@loop-engine/sdk";
2import { postgresStore, createSchema } from "@loop-engine/adapter-postgres";
3import { memoryStore } from "@loop-engine/adapter-memory";
4import { Pool } from "pg";
5 
6"cmt">// Version A: in-memory (default local dev)
7const memStore = memoryStore();
8const memoryRuntime = await createLoopSystem({ loops: [definition], store: memStore });
9 
10"cmt">// Version B: postgres (durable)
11const pool = new Pool({ connectionString: process.env.DATABASE_URL });
12await createSchema(pool);
13const pgStore = postgresStore(pool);
14const postgresRuntime = await createLoopSystem({ loops: [definition], store: pgStore });
15 
16"cmt">// Loop definitions + transition calls are unchanged across adapters.

1{
2  type: "loop.transition.executed",
3  loopId: "expense.approval",
4  aggregateId: "EXP-2026-009",
5  transitionId: "approve",
6  fromState: "PENDING_APPROVAL",
7  toState: "APPROVED",
8  actor: { type: "human", id: "manager@acme.com" },
9  occurredAt: "2026-03-13T12:49:22.290Z"
10}

1cd loop-examples/postgres-persistence
2pnpm install
3pnpm dev