CheckMate

Inspiration

Every day, millions of people click "I Agree" without understanding what they are consenting to. Privacy policies and Terms of Service are intentionally lengthy, complex, and filled with legal jargon that discourages users from reading them. We wanted to bridge this gap between legal transparency and user understanding by creating a tool that empowers people to make informed decisions before accepting digital agreements.

What it does

Checkmate is an AI-powered Chrome extension that analyzes privacy policies and Terms of Service in real time. It translates dense legal text into simple explanations, assigns trust scores based on potential risks, highlights concerning clauses, and enables users to compare policy updates over time. Instead of overwhelming users with pages of legal language, Checkmate provides actionable insights in seconds.

How we built it

We built Checkmate as a Chrome extension using Plasmo, React, TypeScript, and CSS for the frontend experience. The extension injects an overlay into supported webpages and provides an intuitive popup interface for users.

For the analysis engine, we developed a Next.js backend with dedicated API routes for policy analysis and comparison. We integrated Google Gemini to process policy text and generate structured outputs, including ELI15 summaries, risk assessments, trust scores, and explanations of potentially problematic clauses. Chrome Extension APIs were used to manage storage, communication, and user interactions.

Challenges we ran into

One of our biggest challenges was integrating the browser extension frontend with the AI-powered backend while ensuring smooth communication between the two. We encountered issues involving environment configuration, extension permissions, API connectivity, and synchronization across multiple development branches. We also had to balance functionality with user experience, ensuring that notifications remained useful rather than intrusive.

Accomplishments that we're proud of

• Building a functional end-to-end Chrome extension prototype within a hackathon timeline. • Successfully integrating AI-driven legal policy analysis. • Simplifying complex policies into understandable summaries. • Implementing trust scoring and policy comparison capabilities. • Collaborating effectively as a team while overcoming technical setbacks and debugging challenges.

What we learned

This project taught us the importance of designing AI systems around real user needs rather than novelty alone. We gained hands-on experience with browser extension development, backend API integration, prompt engineering, team collaboration using Git, and building resilient systems under tight deadlines. Most importantly, we learned that accessibility and transparency can transform how users interact with the digital products they use every day.

What's next for CheckMate

Our future vision is to make Checkmate smarter and more personalized. We aim to notify users only when meaningful policy changes occur, support a wider range of legal documents, maintain historical policy records, and expand beyond Chrome to make informed digital consent accessible to everyone.

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