**PostgresSaver**: Persistencia en PostgreSQL (producción)
```bash
npm install @langchain/langgraph-checkpoint-postgres
```
```typescript
import { createAgent } from "langchain";
import { PostgresSaver } from "@langchain/langgraph-checkpoint-postgres";
const DB_URI = "postgresql://user:pass@localhost:5432/mydb";
const checkpointer = PostgresSaver.fromConnString(DB_URI);
await checkpointer.setup();
const agent = createAgent({
model: "mistral:mistral-large-latest",
tools: [weatherTool],
checkpointer,
});
```
También disponibles: **MongoDB** (`@langchain/langgraph-checkpoint-mongodb`),
**Redis** (`@langchain/langgraph-checkpoint-redis`), y **Custom** (implementar `BaseCheckpointSaver`)