---
title: Retrieval Augmented Generation (RAG)
description: Build knowledge-enhanced AI applications with external document retrieval
sidebar_label: RAG (Retrieval Augmented Generation)
sidebar_position: 2
---

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# Retrieval Augmented Generation (RAG)


RAG enables your applications to reference and recall information from external documents. Llama Stack makes Agentic RAG available through OpenAI's Responses API.

## Quick Start

### 1. Start the Server

In one terminal, start the Llama Stack server:

```bash
llama stack list-deps starter | xargs -L1 uv pip install
llama stack run starter
```

### 2. Connect with OpenAI Client

In another terminal, use the standard OpenAI client with the Responses API:

```python
import io, requests
from openai import OpenAI

url = "https://www.paulgraham.com/greatwork.html"
client = OpenAI(base_url="http://localhost:8321/v1/", api_key="none")

# Create vector store - auto-detects default embedding model
vs = client.vector_stores.create()

response = requests.get(url)
pseudo_file = io.BytesIO(str(response.content).encode('utf-8'))
file_id = client.files.create(file=(url, pseudo_file, "text/html"), purpose="assistants").id
client.vector_stores.files.create(vector_store_id=vs.id, file_id=file_id)

resp = client.responses.create(
    model="gpt-4o",
    input="How do you do great work? Use the existing knowledge_search tool.",
    tools=[{"type": "file_search", "vector_store_ids": [vs.id]}],
    include=["file_search_call.results"],
)

print(resp.output[-1].content[-1].text)
```
Which should give output like:
```
Doing great work is about more than just hard work and ambition; it involves combining several elements:

1. **Pursue What Excites You**: Engage in projects that are both ambitious and exciting to you. It's important to work on something you have a natural aptitude for and a deep interest in.

2. **Explore and Discover**: Great work often feels like a blend of discovery and creation. Focus on seeing possibilities and let ideas take their natural shape, rather than just executing a plan.

3. **Be Bold Yet Flexible**: Take bold steps in your work without over-planning. An adaptable approach that evolves with new ideas can often lead to breakthroughs.

4. **Work on Your Own Projects**: Develop a habit of working on projects of your own choosing, as these often lead to great achievements. These should be projects you find exciting and that challenge you intellectually.

5. **Be Earnest and Authentic**: Approach your work with earnestness and authenticity. Trying to impress others with affectation can be counterproductive, as genuine effort and intellectual honesty lead to better work outcomes.

6. **Build a Supportive Environment**: Work alongside great colleagues who inspire you and enhance your work. Surrounding yourself with motivating individuals creates a fertile environment for great work.

7. **Maintain High Morale**: High morale significantly impacts your ability to do great work. Stay optimistic and protect your mental well-being to maintain progress and momentum.

8. **Balance**: While hard work is essential, overworking can lead to diminishing returns. Balance periods of intensive work with rest to sustain productivity over time.

This approach shows that great work is less about following a strict formula and more about aligning your interests, ambition, and environment to foster creativity and innovation.
```

## Architecture Overview

Llama Stack provides OpenAI-compatible RAG capabilities through:

- **Vector Stores API**: OpenAI-compatible vector storage with automatic embedding model detection
- **Files API**: Document upload and processing using OpenAI's file format
- **Responses API**: Enhanced chat completions with agentic tool calling via file search

## Configuring Default Embedding Models

To enable automatic vector store creation without specifying embedding models, configure a default embedding model in your config.yaml like so:

```yaml
vector_stores:
  default_provider_id: faiss
  default_embedding_model:
    provider_id: sentence-transformers
    model_id: nomic-ai/nomic-embed-text-v1.5
```

With this configuration:
- `client.vector_stores.create()` works without requiring embedding model or provider parameters
- The system automatically uses the default vector store provider (`faiss`) when multiple providers are available
- The system automatically uses the default embedding model (`sentence-transformers/nomic-ai/nomic-embed-text-v1.5`) for any newly created vector store
- The `default_provider_id` specifies which vector storage backend to use
- The `default_embedding_model` specifies both the inference provider and model for embeddings

## Vector Store Operations

### Creating Vector Stores

You can create vector stores with automatic or explicit embedding model selection:

```python
# Automatic - uses default configured embedding model and vector store provider
vs = client.vector_stores.create()

# Explicit - specify embedding model and/or provider when you need specific ones
vs = client.vector_stores.create(
    extra_body={
        "provider_id": "faiss",  # Optional: specify vector store provider
        "embedding_model": "sentence-transformers/nomic-ai/nomic-embed-text-v1.5",
        "embedding_dimension": 768  # Optional: will be auto-detected if not provided
    }
)
```
