Stop re-explaining yourself to Agents. Give it the right context, right when needed.

LLMs are stateless — each conversation starts from scratch. ContextBook gives your AI tools a persistent, searchable knowledge library to draw the right context when they need it. No bloatware, no pre-loaded junk. Just the right information, at the right time.

How It Works

mermaid

flowchart LR
    AI["🤖 AI Clients\nClaude · Cursor · Windsurf"]
    Browser["🌐 Browser Dashboard"]
    MCP["🔌 MCP Server :8081\n8 Bearer-authenticated tools"]
    API["⚙️ REST API :8080\nOAuth 2.0 · Books · Pages · Search"]
    DB["🗄️ PostgreSQL\npgvector · pg_trgm"]
    VOYAGE["🧠 Voyage AI\nvoyage-4 (1024-dim)"]

    AI -- "MCP · Bearer Token" --> MCP
    Browser -- "Session · HTTP JSON" --> API
    MCP --- DB
    API --- DB
    API -- "OAuth 2.0 PKCE" --> AI
    DB --- VOYAGE

Two Go binaries share a PostgreSQL database:

API server (cmd/api) — the control plane: user login, OAuth 2.0, dashboard, book/page CRUD
MCP server (cmd/mcp) — the data plane: 8 MCP tools for AI agents, protected by Bearer tokens

MCP Tools

All tools require a valid Bearer token and are scoped to the authenticated user.

Tool	Description
`book_create_or_update`	Create a Book or update its metadata
`book_list`	Paginated list of Book metadata
`book_get`	Retrieve all pages of a Book
`page_insert`	Push an atomic page into a Book; embeds immediately
`page_update`	Replace a page's content; re-embeds
`page_delete`	Remove a page (indices not re-numbered)
`page_search`	Semantic search across all Books
`readme`	Returns the usage guide (call once per session)

Quick Start

Prerequisites

Go 1.26+
Node.js 22+
PostgreSQL 16+ with pgvector and pg_trgm
A Voyage AI API key

1. Set up the database

sql

CREATE DATABASE contextbook_db;
\c contextbook_db
CREATE EXTENSION IF NOT EXISTS vector;
CREATE EXTENSION IF NOT EXISTS pg_trgm;

Migrations run automatically on API server startup.

2. Configure environment

bash

cp .env.example backend/.env
# Edit backend/.env — set DATABASE_URL, API_KEY_SALT, VOYAGE_API_KEY

3. Run the backend

bash

cd backend
go run ./cmd/api/main.go    # API + dashboard (:8080)
go run ./cmd/mcp/main.go     # MCP server (:8081)

4. Run the frontend (optional)

bash

cd frontend
npm install && npm run dev    # Vite dev server on :5173

5. Connect an AI client

For Cursor (.cursor/mcp.json):

json

{
  "mcpServers": {
    "contextbook": {
      "url": "http://localhost:8081/mcp"
    }
  }
}

For any MCP-compatible client, point the server URL to http://localhost:8081/mcp.

Documentation

Backend README — API routes, auth flows, database schema, MCP tools, configuration
Frontend README — components, routing, design system, development setup
Architecture — full system overview with Mermaid diagrams

Project Structure

context-book/
├── backend/
│   ├── cmd/api/main.go          REST API + auth server
│   ├── cmd/mcp/main.go          MCP tool server
│   └── internal/
│       ├── api/                  REST handlers + routes
│       ├── auth/                 OAuth 2.0 PKCE, sessions, SSO
│       ├── context/              Book/Page business logic
│       ├── db/                  pgx queries + migrations
│       ├── embedding/            Voyage AI client
│       ├── logger/               slog + HTTP access logging
│       └── mcp/                  8 MCP tool handlers
├── frontend/                     React 19 + Vite + TypeScript SPA
│   └── src/
│       ├── App.tsx               Router + app shell
│       ├── lib/api.ts            HTTP client
│       └── components/           UI components
├── Dockerfile                    API server container
├── Dockerfile.mcp                MCP server container
└── go.work                       Go workspace