---
title: LLama2 | LlamaIndex OSS Documentation
---

## Installation

```
npm i llamaindex @llamaindex/replicate
```

## Usage

```
import { LlamaDeuce, DeuceChatStrategy } from "@llamaindex/replicate";
import { Document, VectorStoreIndex, Settings } from "llamaindex";


Settings.llm = new LlamaDeuce({ chatStrategy: DeuceChatStrategy.META });
```

## Usage with Replication

```
import { Settings } from "llamaindex";
import { LlamaDeuce, DeuceChatStrategy, ReplicateSession } from "@llamaindex/replicate";


const replicateSession = new ReplicateSession({
  replicateKey,
});


Settings.llm = new LlamaDeuce({
  chatStrategy: DeuceChatStrategy.META,
  replicateSession,
});
```

## Load and index documents

For this example, we will use a single document. In a real-world scenario, you would have multiple documents to index.

```
const document = new Document({ text: essay, id_: "essay" });


const index = await VectorStoreIndex.fromDocuments([document]);
```

## Query

```
const queryEngine = index.asQueryEngine();


const query = "What is the meaning of life?";


const results = await queryEngine.query({
  query,
});
```

## Full Example

```
import { LlamaDeuce, DeuceChatStrategy } from "@llamaindex/replicate";
import { Document, VectorStoreIndex, Settings } from "llamaindex";


// Use the LlamaDeuce LLM
Settings.llm = new LlamaDeuce({ chatStrategy: DeuceChatStrategy.META });


async function main() {
  const document = new Document({ text: essay, id_: "essay" });


  // Load and index documents
  const index = await VectorStoreIndex.fromDocuments([document]);


  // get retriever
  const retriever = index.asRetriever();


  // Create a query engine
  const queryEngine = index.asQueryEngine({
    retriever,
  });


  const query = "What is the meaning of life?";


  // Query
  const response = await queryEngine.query({
    query,
  });


  // Log the response
  console.log(response.response);
}
```

## API Reference

- [LlamaDeuce](/docs/api/variables/LlamaDeuce/index.md)
- [DeuceChatStrategy](/docs/api/variables/DeuceChatStrategy/index.md)