**Ventaja clave de LangChain:** Cambiar de proveedor sin reescribir código
```typescript
// OpenAI
import { ChatOpenAI } from "@langchain/openai";
const model = new ChatOpenAI({
model: "gpt-4.1-mini"
});
```
```typescript
// Anthropic Claude
import { ChatAnthropic } from "@langchain/anthropic";
const model = new ChatAnthropic({
model: "claude-sonnet-4-6"
});
```