AI-POWERED EMAIL CLIENT

Project Overview

Normal Human is a full-stack SaaS email client that connects to Gmail via the Nylas API, indexes every message with OpenAI vector embeddings, and surfaces an AI copilot directly inside the compose window. It was built to solve a specific problem: existing email clients treat AI as a bolt-on feature. Normal Human puts AI at the center — from real-time writing suggestions to a chat interface that can reason over your entire inbox history.

Built with Next.js 14, Nylas v7, OpenAI GPT-4, Orama (in-memory vector search), Clerk, and Stripe — the application is production-ready, subscription-gated, and deployable with a single database URL.

Scope of Work

We built the full product — email infrastructure, AI features, search engine, auth, payments, and UI. Every part of the stack was designed to work together as a cohesive, production-ready SaaS.

Key deliverables included:

• Gmail Integration via Nylas: Full OAuth flow so users connect their inbox in one click. Incremental delta-sync with nextDeltaToken tracking keeps the database current without redundant full-fetches — scales to large mailboxes without hammering the API.

• Ask AI — RAG Inbox Chat: Users chat with their entire inbox using GPT-4. Every email is embedded at sync time and stored in a persisted Orama binary index, enabling zero cold-start semantic retrieval — answers are context-aware and backed by the actual thread history.

• AI Compose & Copilot: Full email drafting from a short prompt via GPT-3.5-turbo, plus ghost-text inline completions as the user types — accepted with a single Tab keypress. Both features stream tokens to the browser so AI feels instant.

• Hybrid Semantic Search: Orama runs client-side with BM25 full-text search combined with 1536-dim cosine similarity search (threshold 0.80). The index persists across page reloads — no re-embedding on every visit.

• Stripe Subscription Billing: Free tier (50 AI interactions/day) and premium tier (unlimited), with a complete funnel from landing page → auth → email connect → AI usage → upgrade prompt. Daily usage is tracked per user via a ChatbotInteraction model.

• Resizable Three-Panel UI: Sidebar / thread list / reading pane with panel sizes persisted via cookies. TipTap rich-text compose editor with custom AI extensions, kbar command palette, and full dark/light mode theming.