Understanding RAG Architecture in Sidebar with Gemini

How we use Retrieval-Augmented Generation to provide contextual AI responses

March 15, 2025

The Challenge of Context in AI

Have you ever asked ChatGPT about a webpage you're reading, only to realize you'd need to copy-paste chunks of text for it to understand the context? That's the problem we set out to solve with the Sidebar with Gemini extension. Our journey led us to implement a RAG (Retrieval-Augmented Generation) architecture, and today, I'm excited to share how we did it.

"The key to intelligent AI responses isn't just in the model's capabilities, but in its ability to understand the context of your questions."

What is RAG, Really?

Before we dive into the technical details, let's understand what RAG means in practical terms. Imagine you're having a conversation with a very knowledgeable friend about an article you're both reading. Your friend can see the article, understand its content, and provide responses that are specifically tailored to what you're discussing. That's essentially what RAG does for AI interactions.

Real-world example: When you ask "What's the main argument here?", our extension doesn't just pass your question to Gemini. Instead, it first analyzes the webpage, extracts the relevant content, and provides this context along with your question. It's like giving the AI a pair of eyes to see what you're seeing.

RAG Architecture Overview

Here's a visual representation of how our RAG implementation works:

graph TD
    subgraph Retrieval
        A[Web Page Content] -->|Extract| B[Content Processor]
        B -->|Process| C[Context Chunks]
        D[User Query] -->|Combine| E[Query + Context]
    end

    subgraph Augmentation
        C -->|Relevant Context| E
        E -->|Enhanced Prompt| F[Gemini API]
    end

    subgraph Generation
        F -->|Process| G[AI Response]
        G -->|Format| H[Sidebar Display]
    end

    style Retrieval fill:#f0f7ff,stroke:#0066cc
    style Augmentation fill:#fff7f0,stroke:#cc6600
    style Generation fill:#f0fff7,stroke:#00cc66
                        

RAG Components Explanation

1. Retrieval Phase

Content Extraction

  • The extension extracts relevant content from the active web page
  • Content is processed to remove irrelevant elements (ads, navigation, etc.)
  • Text is split into meaningful chunks for context

Context Processing

  • Chunks are processed to maintain semantic relevance
  • Key information is identified and preserved
  • Metadata is attached for context enhancement

2. Augmentation Phase

Context Integration

  • User queries are combined with relevant page context
  • Context is selected based on relevance to the query
  • Prompt engineering is applied to optimize context usage

Query Enhancement

  • Queries are enriched with page metadata
  • Context is structured for optimal AI processing
  • Relevance scoring helps prioritize context chunks

3. Generation Phase

AI Processing

  • Enhanced queries are sent to Gemini API
  • Responses are generated using provided context
  • Output is optimized for sidebar display

Response Formatting

  • AI responses are formatted for readability
  • Context sources are cited when relevant
  • Interactive elements are added as needed

The Technical Implementation

For the developers among you, here's a look at how we structure our RAG implementation. I've simplified it to show the core concepts:

class RAGProcessor {
    // Extract content from webpage
    extractContent() {
        // Remove noise
        // Identify main content
        // Process text
    }

    // Process content into chunks
    processChunks() {
        // Split content
        // Add metadata
        // Score relevance
    }

    // Enhance query with context
    enhanceQuery(userQuery, chunks) {
        // Select relevant chunks
        // Combine with query
        // Optimize prompt
    }

    // Generate response
    async generateResponse(enhancedQuery) {
        // Call Gemini API
        // Process response
        // Format output
    }
}

Results and Impact

After implementing RAG, we've seen significant improvements in the quality of AI responses:

More Accurate

Responses are more precise and relevant to the page content.

Fewer Hallucinations

The AI sticks to facts from the page instead of making things up.

Faster Responses

Smart context selection means we process only what's needed.

What's Next?

We're just scratching the surface of what's possible with RAG architecture. In the coming months, we're exploring:

  • Multi-modal context understanding (including images and videos)
  • Real-time context updating as page content changes
  • More sophisticated relevance scoring algorithms