Percepta

Percepta is an intelligent Chrome extension that provides AI-powered webpage analysis and interactive conversations about web content.

Features

Smart Page Analysis

• Capture and analyze any webpage with a single click
• AI-powered descriptions that understand page content and context
• Automatic screenshot integration for visual reference
• Intelligent content chunking for optimal processing

Interactive Conversations

• Ask follow-up questions about analyzed pages
• Context-aware responses that remember your conversation
• Suggested action buttons for natural conversation flow
• Multi-tab support with independent conversations per tab

Wikipedia Integration

• Automatic entity recognition and linking
• Hover previews for Wikipedia articles
• Seamless access to additional context without leaving the page

Customizable Experience

• Themes: Light, Dark, High Contrast, or Auto (system preference)
• Languages: English, Spanish (Español), Japanese (日本語)
• Font Sizes: 5 size options for comfortable reading
• Detail Levels: Choose between brief, normal, or detailed responses

Accessibility First

• Full keyboard navigation support
• Screen reader optimized with live regions
• ARIA labels and semantic HTML throughout
• Configurable text-to-speech announcements
• High contrast theme for visual accessibility

Conversation Management

• Automatic conversation saving and archiving
• Browse and restore previous conversations
• Per-tab conversation history
• Clear visual indicators for active sessions

Architecture

Core Components

Background Service Worker (background.js)

• Manages extension lifecycle and message routing
• Handles screenshot capture and context menus
• Coordinates between tabs and the side panel

Side Panel (sidepanel/)

• Main conversation interface
• Real-time streaming responses
• Wikipedia preview tooltips
• Tab-aware conversation switching

Popup (popup.html, popup.js)

• Quick access to page analysis
• Conversation history browser
• Settings management
• Recent activity overview

AI Engine (ai/)

• sessionManager.js - Manages AI sessions and streaming
• contextChunker.js - Intelligent content splitting
• modelFactory.js - AI model initialization
• imageUtils.js - Screenshot processing

Storage (background/conversationStorage.js)

• Persistent conversation history
• Metadata tracking (timestamps, URLs, titles)
• Efficient retrieval and filtering

Internationalization

Fully localized in three languages:

• English (_locales/en/)
• Spanish (_locales/es/)
• Japanese (_locales/ja/)

Utilities

Wikipedia Integration (utils/)

• wikiLinker.js - Entity detection and linking
• wikiPreview.js - Hover preview tooltips
• wikiUtils.js - Wikipedia API interactions

Accessibility (utils/streamAccessibility.js)

• Screen reader announcements
• Live region management
• Streaming content accessibility

Setup Wizard

First-time users are guided through an interactive setup:

1. Welcome - Introduction to Percepta
2. Theme - Choose your visual preference
3. Detail Level - Set response verbosity
4. Accessibility - Configure assistive features
5. Shortcuts - Learn keyboard navigation
6. Completion - Start using Percepta

Technology Stack

• Chrome Extension Manifest V3
• Chrome Built-in AI API (Prompt API)
• Offscreen Documents for AI processing
• Side Panel API for persistent UI
• Chrome Storage API for data persistence
• Text-to-Speech API for accessibility

Key Features in Detail

Multi-Tab Conversation Management

Each browser tab maintains its own independent conversation. Switch between tabs seamlessly, and Percepta automatically restores the correct conversation context.

Intelligent Content Processing

Pages are analyzed using smart chunking that preserves context while staying within the model limits. Screenshots are automatically captured and included for visual understanding.

Streaming Responses

AI responses stream in real-time, providing immediate feedback. The interface remains responsive during generation, with proper loading indicators.

Persistent History

All conversations are automatically saved with metadata (timestamp, page URL, title). Browse your history, restore previous conversations, or clear old sessions.

Action Buttons

The AI can suggest relevant follow-up questions as clickable buttons, making conversations more natural and discoverable.

Browser Requirements

• Chrome 138+ (for Built-in AI API support)
• Prompt API for Gemini Nano enabled in chrome://flags
• Prompt API for Gemini Nano with Multimodal Input enabled in chrome://flags

Read more about the requirements in the Prompt API documentation

Privacy

All AI processing happens locally using Chrome's built-in AI. Conversations are stored locally in Chrome's storage.

The data points that are sent to Chrome's sync storage are:

• Detail Level
• Language
• Theme
• Font Size

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Version: 1.0
License: MIT Manifest Version: 3