# Vibe Knowledge — Claude Code Sessions, Automatically Turned Into Flashcards

> Vibe Knowledge (バイブナレッジ) is a free, open-source tool that automatically converts your Claude Code coding sessions into spaced-repetition flashcards. No extra effort, no new apps, no cloud account required.

URL: https://vibeknowledge.dev/
GitHub: https://github.com/Shown06/vibe-knowledge
License: MIT
Language: English / 日本語
Last updated: 2026-06-16

---

## What Is Vibe Knowledge? (概要)

Vibe Knowledge is an OSS developer learning tool that hooks into Claude Code's event system. Every time you use Claude Code — editing files, running commands, writing code — Vibe Knowledge silently captures what happened and converts it into plain-language flashcards. After a week of vibe-coding, you accumulate 100+ cards, all grounded in your own real projects.

The tool bridges the gap between "building fast with AI" and "actually retaining what you learned." Vibe coders can now explain what they built to clients, teammates, or in a job interview — in their own words.

---

## Key Features (主な機能)

### Auto-capture (自動キャプチャ)
- Hooks into every Claude Code Edit, Write, and Bash call automatically
- Zero configuration per project — install once, works everywhere
- Capture hook runs in milliseconds without calling any AI
- No latency, zero cost at capture time

### Flashcard Generation (フラッシュカード自動生成)
- After each session, Claude Haiku extracts concepts in plain language
- Each card contains: one-sentence definition, why-we-used-it context, real-world analogy
- Cards are organized by project automatically
- Runs in background after session ends — never slows down your coding

### Spaced Repetition Quiz / SM-2 (間隔反復クイズ)
- Built-in spaced repetition using the SM-2 algorithm
- Self-grade each card: forgot / hazy / got it
- Algorithm automatically schedules next review date
- Proven method for long-term memory retention

### MCP Server (MCPサーバー)
- Register Vibe Knowledge as an MCP server in Claude Code
- Query your own knowledge base directly from inside coding sessions
- Example: "What have I learned about webhooks?" → instant answer from your cards
- Your flashcards become a searchable second brain

### Concept Map (概念マップ)
- Force-directed graph of your top 40 terms
- Visualize clusters and connections between concepts
- Identify gaps in your knowledge
- Watch your understanding grow over time

### Privacy-first Design (プライバシーファースト)
- All data stored locally at ~/.claude/vibe-knowledge/data/
- Nothing transmitted to any external server
- API keys (sk-..., ghp_...), Bearer tokens, .env file contents, .pem/.key files → auto-replaced with [secret masked] before storage
- 100% auditable: every line of capture logic is open source on GitHub

### Local Viewer / Dashboard (ローカルビューワー)
- Open view/index.html in your browser — no server, no bundler, no internet required
- 6 tabs: Cards / Projects / Glossary / Concept Map / Quiz / Retrospective
- Full offline support
- No external dependencies

---

## Installation (インストール方法)

**Requirements:** Claude Code (Claude Pro or Claude Max subscription)

**Install in under 30 seconds:**
```
bash <(curl -fsSL https://raw.githubusercontent.com/Shown06/vibe-knowledge/main/install.sh)
```

The installer:
1. Creates ~/.claude/vibe-knowledge/ directory structure
2. Registers the capture hook in Claude Code's settings.json
3. Sets up the MCP server configuration (optional)
4. No cloud account, no API key, no configuration required

---

## MCP Server Setup (MCPサーバー設定)

To query your knowledge base from inside Claude Code:

1. Add to your Claude Code MCP configuration:
```json
{
  "mcpServers": {
    "vibe-knowledge": {
      "command": "node",
      "args": ["~/.claude/vibe-knowledge/mcp/server.js"]
    }
  }
}
```

2. Available MCP tools:
   - `vk_search_cards` — Search flashcards by keyword
   - `vk_grade_term` — Grade a card (spaced repetition)
   - `vk_get_stats` — Get learning statistics

---

## How Cards Are Generated (カード生成の仕組み)

1. Claude Code hook fires on every tool call (Edit, Write, Bash, etc.)
2. Hook captures: tool name, file paths, command context (secrets masked)
3. After session ends, background distill process calls Claude Haiku
4. Haiku extracts: concept term, plain-language definition, why it was used, analogy
5. Card is written to ~/.claude/vibe-knowledge/data/cards.jsonl
6. Card is immediately available in the local viewer and MCP server

---

## Data Storage (データ保存場所)

| File | Contents |
|------|----------|
| ~/.claude/vibe-knowledge/data/cards.jsonl | All flashcards (append-only) |
| ~/.claude/vibe-knowledge/data/projects.json | Project metadata |
| ~/.claude/vibe-knowledge/data/quiz-state.json | SM-2 review schedule |
| ~/.claude/hooks/vibe-knowledge/ | Capture hook scripts |

---

## Pricing (料金)

**Free. Forever. Open Source.**

- No subscription required (beyond your existing Claude Pro/Max plan)
- No API key (uses Claude Pro quota for distillation)
- No cloud account
- No storage costs
- MIT License — fork, modify, redistribute freely

---

## FAQ (よくある質問)

**Q: Does it slow down my Claude Code sessions?**
A: No. The capture hook runs in milliseconds and calls no AI during your session. Flashcard generation happens in the background after the session ends.

**Q: Is my code safe? What about API keys?**
A: API keys (sk-..., ghp_...), Bearer tokens, .env contents, and private key files are automatically masked before any storage. Nothing leaves your machine.

**Q: Does it work offline?**
A: Yes. The local viewer (view/index.html) works without internet, server, or bundler. Just open it in any browser.

**Q: Which AI tools does it support?**
A: Currently Claude Code only. The tool hooks into Claude Code's native event system.

**Q: Do I need a separate API key?**
A: No. Vibe Knowledge uses your existing Claude Pro/Max subscription quota for flashcard distillation. No additional billing.

**Q: Can I use it on multiple projects?**
A: Yes. Install once and it works across every Claude Code project automatically. Cards are organized by project.

**Q: Can I query my knowledge inside Claude Code?**
A: Yes. Set it up as an MCP server and ask "What have I learned about React hooks?" directly from any Claude Code session.

**Q: Is it open source? Can I contribute?**
A: Yes, MIT license. GitHub: https://github.com/Shown06/vibe-knowledge — pull requests and issues welcome.

**Q: バイブコーディング中に使えますか？**
A: はい、まさにそのために作られています。Claude Codeで開発するたびに自動でカードが増え、一切追加の操作が不要です。

**Q: どのくらいのカードが溜まりますか？**
A: 1週間のコーディングで100枚以上が目安です。プロジェクトの規模・複雑さによって変動します。

---

## Use Cases (ユースケース)

- **バイブコーダーの学習強化**: Claude Codeで高速開発しながら、自動的に技術知識を体系化する
- **クライアント説明力の向上**: 自分が作ったものを顧客や非技術者に平易な言葉で説明できるようになる
- **チームのナレッジ共有**: プロジェクトで学んだ概念を可視化してチームで共有
- **プログラミング学習の記録**: 学習の軌跡を自動保存して成長を実感
- **技術面接対策**: 実際のプロジェクト経験から生まれたカードで面接準備

---

## Related Links (関連リンク)

- GitHub Repository: https://github.com/Shown06/vibe-knowledge
- Installation Script: https://raw.githubusercontent.com/Shown06/vibe-knowledge/main/install.sh
- License: MIT (https://opensource.org/licenses/MIT)
- Dashboard: https://vibeknowledge.dev/app/