Document notary

• 

  Document notarize

Inspiration

In a world where digital content and legal agreements are increasingly created and shared online, proving authorship, authenticity, and timestamp has become a serious challenge. Freelancers, artists, and legal professionals need a simple, secure, and verifiable way to prove the integrity and authorship of their work. This project was born from the desire to empower these individuals by offering a blockchain-based notary system that’s easy to use and resistant to tampering.

What it does

Our platform allows users to:

1. Upload a document.
2. Generate a unique SHA-256 hash of the content.
3. Sign the hash using their MetaMask wallet to prove ownership.
4. Store the hash, wallet address, and timestamp on the blockchain via a smart contract.
5. Receive a public certificate (PDF or link) that includes:
   • The wallet address
   • Document hash
   • Timestamp and block number
   • Public verification link

We also offer an optional subscription model:

• Free trial: 1 month
• Pro tier: Unlimited certificates + professional PDF export (payment via revenuecat)

How we built it

• Frontend: Vue.js 3 with Tailwind CSS for responsive and clean UI
• Blockchain interaction: Algogrand (nodely)
• Backend & Database: Supabase/PostgreSQL for storing user plans and document metadata

Challenges we ran into

• Ensuring file hashes are generated consistently across platforms
• Dealing with gas fees and testnet performance on Polygon Mumbai
• Syncing blockchain transaction confirmation with backend operations

Accomplishments that we're proud of

• End-to-end workflow: from upload to blockchain notarization to PDF certificate
• Clean and intuitive user interface for non-technical users
• Building a scalable model with subscription plans and RevenueCat integration

What we learned

• Deep understanding of document hashing and its role in proof of authenticity
• Smart contract development with Solidity and best practices for storing minimal data
• Combining Web2 and Web3 technologies in a secure and user-friendly way
• How to handle signature verification and gasless UX alternatives

What's next for Document Notary

• Adding email notifications and QR codes on certificates
• Organization/team features for legal firms or agencies
• Mobile app support and gas fee estimation

Built With

• nodely.io
• revenuecat
• supabase
• vuejs3