ContextPrompt AI

Capture web context and generate AI prompts with optional AI-powered summarization.

ContextOS turns your daily browsing into a structured, searchable knowledge base — and makes it available to any AI conversation. 🔹 CAPTURE • One-click page capture: title, URL, body text, metadata, Open Graph, JSON-LD • Three capture depths: Lightweight (save tokens) · Standard · Deep (full content) • Batch capture all open tabs at once • AI chat extraction from 12 platforms • Text selection toolbar: select text → floating bar → save / AI summarize / translate / copy as Markdown • Auto-capture by URL pattern matching with notification confirmation • Keyboard shortcuts: Ctrl+Shift+C to capture, Ctrl+Shift+P to generate prompt • Right-click context menu: capture page / selected text / link 🔹 KNOWLEDGE GRAPH • NLP keyword extraction with automatic tagging (TF-IDF scoring) • Vector embeddings: all-MiniLM-L6-v2 (384-dim), computed in-browser via Transformers.js • Relationship discovery: semantic similarity, URL domain, tag overlap (Jaccard), temporal proximity • Interactive D3.js force-directed graph visualization • Hybrid search: vector similarity (60%) + BM25 keyword (40%), Reciprocal Rank Fusion 🔹 AI INTEGRATION Three-tier routing with automatic fallback: 1. Chrome Gemini Nano (on-device, when available) 2. Cloud APIs 3. Rule-based NLP (always available, no API needed) AI capabilities: summarization, translation, quality analysis, context fusion, prompt optimization. 🔹 CONTEXT ORCHESTRATION Click "Craft Prompt" on any supported AI platform to: 1. Search your knowledge graph for relevant nodes 2. Include current page context 3. Allocate token budget by model limits 4. Compress and format into a structured context package 5. Preview and insert into the AI chat input 🔹 MCP PROTOCOL Expose your knowledge base to external AI tools via Native Messaging Host: • search_knowledge — semantic search your knowledge graph • get_context — assemble context packages for target models • capture_page — capture current browser tab • list_knowledge — list recent knowledge nodes • get_stats — knowledge graph statistics 🔹 WORKFLOW ENGINE Pre-built multi-step workflows: Academic Research, Competitive Analysis, Code Review, Content Curation. 🔹 PRIVACY-FIRST • All data stored locally in your browser (IndexedDB + Chrome Storage) • Vector embeddings computed in-browser (model downloaded once from CDN, then cached) • No telemetry, no data collection • Cloud AI is optional — only activated when you trigger an AI action with your own API key • MCP Server listens on 127.0.0.1 only (localhost) Supports English and Chinese with runtime language switching.