Metronote

🌟 Inspiration

Notes apps are too cluttered. We often jot down something quickly — whether it's an idea, a phone number, or a to-do — only to forget about it. Over time, this creates a pile of outdated, irrelevant notes.
We believe notes should serve a purpose and have a lifespan.

📝 What it does

Metronote is a lightweight notes app with one key difference:
🕒 Every note has an expiry date.

When a note expires, you get a reminder — and then it’s deleted. This prevents long-term buildup and ensures your notes app stays relevant and clean.

✨ Additional features include:

• Tagging: Organize your notes by topic or context.
• Filtering/Querying: View only notes with specific tags or those expiring soon.
• Minimalist dashboard: Stay focused with a clean, simple UI.

🛠 How we built it

The backend is written in Haskell, which is well-suited for:

• Parsing structured user input (e.g. extracting dates, tags, and content from free-form text)
• Pattern matching for rules around expiry
• Safe handling of database state

We used:

• 📦 Scotty for a lightweight web server
  
• 🧠 Megaparsec for parsing and extracting structured info from natural input
  
• 🗃 SQLite for persistent note storage
  
• 🧪 aeson for handling JSON requests

The frontend is a minimal web UI that allows users to add, view, and explore their notes.

🚧 Challenges we ran into

• Parsing flexible user input: Allowing notes to be written naturally (e.g. “remind me in 3 days #idea”) while still reliably extracting the relevant fields was tricky.
  
• Haskell build ecosystem: Integrating libraries like megaparsec, scotty, and sqlite required careful configuration.
  
• Note expiry logic: We wanted to handle automatic deletion or reminder triggers without constant polling or complex background jobs.

🏆 Accomplishments that we're proud of

• Building a full-stack app in 24 hours with a clean, functional backend
  
• Writing a robust parser from scratch using Haskell's combinator libraries
  
• Creating a minimalist but useful experience that feels different from traditional notes apps

📚 What we learned

• How to use Haskell's strengths — especially parsing and pattern matching — in a real-world application
  
• How to build a web backend from scratch with Scotty, and connect it to a database
  
• The power of constraint-based design: by forcing notes to have an expiry, the app encourages better habits

🔮 What's next for Metronote

• Add support for natural language input (e.g. "remind me in 2 weeks to cancel subscription")
  
• Optional cloud sync and login for persistence across devices
  
• Smarter expiry logic: e.g. tag-based default durations or reminders before deletion
  
• Mobile-friendly UI and local notifications

Built With

• haskell