📝 Versioned Notes App

A full-stack note-taking application with automatic version control. Built with FastAPI (Python) for the backend and Streamlit for the frontend, this app allows users to create, view, and search notes — each update creating a new version.

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🔧 Tech Stack

• Backend: FastAPI + SQLite
• Frontend: Streamlit (React under the hood)
• Search Autocomplete: Custom Trie-based prefix matching
• Data Persistence: SQLite (auto-generated on startup)

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✨ Features

• 🔐 Create notes with title, content, and tags
• 🕓 Each update creates a new version automatically
• 🔍 Smart title-based search using Trie data structure
• 🗂️ View note content and all versions
• 🆕 Create notes via a separate tab
• 🔗 View full notes in a new browser tab
• 💾 Simple local database (SQLite)

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📁 Project Structure

versioned-notes-api/
├── main.py                 # FastAPI app entry
├── crud.py                 # DB access logic
├── models.py               # Pydantic schemas
├── database.py             # SQLite setup
├── routers/
│   └── notes.py            # API routes
├── trie.py                 # TitleTrie class
├── streamlit_frontend.py   # Main UI (search/view)
├── new_note_form.py        # Create new note page
├── view_note.py            # Full-screen note viewer
├── requirements.txt
└── README.md

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🚀 How to Run the Project

1️⃣ Clone the Repository

git clone https://github.com/your-username/versioned-notes-api.git
cd versioned-notes-api

2️⃣ Install Dependencies

pip install -r requirements.txt

This includes fastapi, uvicorn, pydantic, streamlit, and requests.

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3️⃣ Start the FastAPI Backend

uvicorn main:app --reload

Runs on: http://localhost:8000

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4️⃣ Start the Streamlit Apps

Open 3 terminals and run:

🖥️ Viewer UI (search + versions):

streamlit run streamlit_frontend.py

🆕 New Note Form:

streamlit run new_note_form.py --server.port 8502

🔗 Note Viewer:

streamlit run view_note.py --server.port 8503

Then visit:

• localhost:8501 → Search/view notes
• localhost:8502 → Create new notes
• localhost:8503 → View notes in full window

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🧠 Smart Search (Trie)

A custom TitleTrie is used to support fast title-based prefix matching and metadata retrieval. It auto-loads from the DB on startup.

GET /search-title?q=proj
→ returns matches: [{ title, version, timestamp }]

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✅ Future Enhancements

• ✏️ Editable notes (update latest version)
• 🔍 Diff between versions
• 🗃️ Export notes as .txt or .pdf
• 🔐 Add user authentication
• ☁️ Deploy via Render, Railway or HuggingFace Spaces

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📜 License

MIT License © 2025 Paul Gaikwad

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Built to never lose track of your thoughts — one version at a time.