# GenAI

## Overview

Feast provides robust support for Generative AI applications, enabling teams to build, deploy, and manage feature infrastructure for Large Language Models (LLMs) and other Generative AI (GenAI) applications. With Feast's vector database integrations and feature management capabilities, teams can implement production-ready Retrieval Augmented Generation (RAG) systems and other GenAI applications with the same reliability and operational excellence as traditional ML systems.

## Key Capabilities for GenAI

### Vector Database Support

Feast integrates with popular vector databases to store and retrieve embedding vectors efficiently:

* **Milvus**: Full support for vector similarity search with the `retrieve_online_documents_v2` method
* **SQLite**: Local vector storage and retrieval for development and testing
* **Elasticsearch**: Scalable vector search capabilities
* **Postgres with PGVector**: SQL-based vector operations
* **Qdrant**: Purpose-built vector database integration

These integrations allow you to:

* Store embeddings as features
* Perform vector similarity search to find relevant context
* Retrieve both vector embeddings and traditional features in a single API call

### Retrieval Augmented Generation (RAG)

Feast simplifies building RAG applications by providing:

1. **Embedding storage**: Store and version embeddings alongside your other features
2. **Vector similarity search**: Find the most relevant data/documents for a given query
3. **Feature retrieval**: Combine embeddings with structured features for richer context
4. **Versioning and governance**: Track changes to your document repository over time

The typical RAG workflow with Feast involves:

```
┌─────────────┐     ┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│  Document   │     │  Document   │     │    Feast    │     │     LLM     │
│  Processing │────▶│  Embedding  │────▶│   Feature   │────▶│   Context   │
│             │     │             │     │    Store    │     │  Generation  │
└─────────────┘     └─────────────┘     └─────────────┘     └─────────────┘
```

### Transforming Unstructured Data to Structured Data

Feast provides powerful capabilities for transforming unstructured data (like PDFs, text documents, and images) into structured embeddings that can be used for RAG applications:

* **Document Processing Pipelines**: Integrate with document processing tools like Docling to extract text from PDFs and other document formats
* **Chunking and Embedding Generation**: Process documents into smaller chunks and generate embeddings using models like Sentence Transformers
* **On-Demand Transformations**: Use `@on_demand_feature_view` decorator to transform raw documents into embeddings in real-time
* **Batch Processing with Spark**: Scale document processing for large datasets using Spark integration

The transformation workflow typically involves:

1. **Raw Data Ingestion**: Load documents or other data from various sources (file systems, databases, etc.)
2. **Text Extraction**: Extract text content from unstructured documents
3. **Chunking**: Split documents into smaller, semantically meaningful chunks
4. **Embedding Generation**: Convert text chunks into vector embeddings
5. **Storage**: Store embeddings and metadata in Feast's feature store

### Feature Transformation for LLMs

Feast supports transformations that can be used to:

* Process raw text into embeddings
* Chunk documents for more effective retrieval
* Normalize and preprocess features before serving to LLMs
* Apply custom transformations to adapt features for specific LLM requirements

## Use Cases

### Document Question-Answering

Build document Q\&A systems by:

1. Storing document chunks and their embeddings in Feast
2. Converting user questions to embeddings
3. Retrieving relevant document chunks
4. Providing these chunks as context to an LLM

### Knowledge Base Augmentation

Enhance your LLM's knowledge by:

1. Storing company-specific information as embeddings
2. Retrieving relevant information based on user queries
3. Injecting this information into the LLM's context

### Semantic Search

Implement semantic search by:

1. Storing document embeddings in Feast
2. Converting search queries to embeddings
3. Finding semantically similar documents using vector search

### Scaling with Spark Integration

Feast integrates with Apache Spark to enable large-scale processing of unstructured data for GenAI applications:

* **Spark Data Source**: Load data from Spark tables, files, or SQL queries for feature generation
* **Spark Offline Store**: Process large document collections and generate embeddings at scale
* **Spark Batch Materialization**: Efficiently materialize features from offline to online stores
* **Distributed Processing**: Handle gigabytes of documents and millions of embeddings

This integration enables:

* Processing large document collections in parallel
* Generating embeddings for millions of text chunks
* Efficiently materializing features to vector databases
* Scaling RAG applications to enterprise-level document repositories

## Model Context Protocol (MCP) Support

Feast supports the Model Context Protocol (MCP), which enables AI agents and applications to interact with your feature store through standardized MCP interfaces. This allows seamless integration with LLMs and AI agents for GenAI applications.

### Key Benefits of MCP Support

* **Standardized AI Integration**: Enable AI agents to discover and use features dynamically without hardcoded definitions
* **Easy Setup**: Add MCP support with a simple configuration change and `pip install feast[mcp]`
* **Agent-Friendly APIs**: Expose feature store capabilities through MCP tools that AI agents can understand and use
* **Production Ready**: Built on top of Feast's proven feature serving infrastructure

### Getting Started with MCP

1. **Install MCP support**:

   ```bash
   pip install feast[mcp]
   ```
2. **Configure your feature store** to use MCP:

   ```yaml
   feature_server:
     type: mcp
     enabled: true
     mcp_enabled: true
     mcp_server_name: "feast-feature-store"
     mcp_server_version: "1.0.0"
   ```

### How It Works

The MCP integration uses the `fastapi_mcp` library to automatically transform your Feast feature server's FastAPI endpoints into MCP-compatible tools. When you enable MCP support:

1. **Automatic Discovery**: The integration scans your FastAPI application and discovers all available endpoints
2. **Tool Generation**: Each endpoint becomes an MCP tool with auto-generated schemas and descriptions
3. **Dynamic Access**: AI agents can discover and call these tools dynamically without hardcoded definitions
4. **Standard Protocol**: Uses the Model Context Protocol for standardized AI-to-API communication

### Available MCP Tools

The fastapi\_mcp integration automatically exposes your Feast feature server's FastAPI endpoints as MCP tools. This means AI assistants can:

* **Call `/get-online-features`** to retrieve features from the feature store
* **Use `/health`** to check server status

For a complete example, see the [MCP Feature Store Example](https://docs.feast.dev/v0.56-branch/tutorials/mcp_feature_store).

## Learn More

For more detailed information and examples:

* [Vector Database Reference](https://docs.feast.dev/v0.56-branch/reference/alpha-vector-database)
* [RAG Tutorial with Docling](https://docs.feast.dev/v0.56-branch/tutorials/rag-with-docling)
* [RAG Fine Tuning with Feast and Milvus](https://docs.feast.dev/v0.56-branch/tutorials/rag-retriever)
* [Milvus Quickstart Example](https://github.com/feast-dev/feast/tree/master/examples/rag/milvus-quickstart.ipynb)
* [MCP Feature Store Example](https://docs.feast.dev/v0.56-branch/tutorials/mcp_feature_store)
* [MCP Feature Server Reference](https://github.com/feast-dev/feast/blob/v0.55-branch/docs/reference/feature-servers/mcp-feature-server.md)
* [Spark Data Source](https://docs.feast.dev/v0.56-branch/reference/data-sources/spark)
* [Spark Offline Store](https://docs.feast.dev/v0.56-branch/reference/offline-stores/spark)
* [Spark Compute Engine](https://docs.feast.dev/v0.56-branch/reference/compute-engine/spark)