Extension is All You Need

Inspiration

When applying for jobs, we realized that some of the most important emails—interview invitations, follow-ups, or even rejection letters—often end up buried in Other or Junk folders.
Manually checking these folders every day felt inefficient and mentally draining.

This made us question a core assumption of email:
why are we still managing emails as raw messages instead of actions and relationships?

That question became the starting point of Extension is all you need.

What it does

Extension is all you need is an AI-powered browser extension that transforms your inbox into an intelligent action system.

It automatically:

Classifies emails into Read, Reply, or Ignore
Further categorizes messages by context (Work, School, Other)
Generates concise summaries so users can understand emails at a glance
Provides context-aware AI-generated replies based on user intent

Beyond individual emails, the system introduces Inbox Brain—a relationship-centered view of the inbox.
It identifies users’ most frequent contacts, summarizes long-term conversations, and provides clickable references back to original emails, allowing users to navigate conversations by people, not messages.

To make this experience more intuitive and memorable, we also designed Social Space, an arcade-style interface where frequent contacts are visualized as characters in a shared space, turning inbox navigation into a spatial and human-centered experience.

How we built it

The extension connects securely to the user’s inbox and processes email content using large language models.
A key design choice was reusing users’ unused ChatGPT/Claude Plus quota to analyze emails efficiently and cost-effectively.

We focused on:

Action-oriented classification instead of keyword-based filtering
Summarization with citations to preserve transparency
Modular design so features like Inbox Brain and Social Space share the same underlying intelligence

Challenges and learnings

The challenge was designing a playful interface without making the product feel less serious.
This pushed us to think deeply about how UI can reduce cognitive load while still maintaining clarity and purpose.

Through this project, we learned how combining strong product intuition with AI capabilities can fundamentally reshape everyday tools—not by adding more features, but by changing how users think and act.