JAI — Job Application Intelligence

AI-powered Chrome extension and Next.js dashboard that auto-tailors resumes to job descriptions using Google Gemini, with Overleaf LaTeX integration and one-click job application autofill.

Architecture

┌──────────────────┐      ┌──────────────────────────┐      ┌──────────────┐
│  Chrome Extension│◄────►│  Next.js Web Dashboard   │◄────►│   MongoDB    │
│  (Manifest V3)   │      │  (App Router + API Routes)│      │  (Atlas)     │
└────────┬─────────┘      └────────────┬─────────────┘      └──────────────┘
         │                             │
         ▼                             ▼
┌──────────────────┐      ┌──────────────────────────┐
│  Google Gemini   │      │  Google OAuth (NextAuth)  │
│  (Resume AI)     │      │  + Gmail API              │
└──────────────────┘      └──────────────────────────┘
         │
         ▼
┌──────────────────┐
│  Overleaf        │
│  (LaTeX → PDF)   │
└──────────────────┘

Features

• AI Resume Tailoring — Gemini rewrites your LaTeX resume to match any job description, preserving layout and formatting while optimizing content for ATS systems.
• Overleaf Automation — Auto-opens Overleaf, injects generated LaTeX, and triggers compilation for instant PDF download.
• Job Application Autofill — Scans application forms and fills fields (name, email, education, demographics, work authorization) from your saved profile using fuzzy matching.
• API Key Rotation — Extension supports multiple Gemini API keys with automatic failover on rate limits, countdown retry, and cancellation.
• Web Dashboard — Full-stack Next.js app with Google OAuth, resume upload/parsing, job search (JSearch/RapidAPI), application tracking, and Gmail inbox scanning.
• Profile Management — Onboarding flow captures education, work history, skills, and demographics. Data drives both the autofill engine and resume generation.

Project Structure

extension/                    # Chrome Extension (Manifest V3)
├── manifest.json             # Permissions, content scripts, service worker
├── popup/                    # Side panel UI (login, automate, autofill)
├── options/                  # Settings page (LaTeX resume editor)
├── scripts/
│   ├── background.js         # Service worker — Gemini API calls, key rotation
│   ├── content_jd.js         # Extracts JD text from active tab
│   ├── content_overleaf.js   # Automates Overleaf editor injection
│   └── content_autofill.js   # Smart form-filling with field detection
└── icons/

web/                          # Next.js 16 Web Dashboard
├── src/
│   ├── app/
│   │   ├── api/              # Server-side API routes
│   │   │   ├── auth/         # NextAuth Google OAuth
│   │   │   ├── profile/      # User profile CRUD
│   │   │   ├── resume/       # Upload, parse, generate, view
│   │   │   ├── sessions/     # Resume generation sessions
│   │   │   ├── jobs/         # JSearch job search proxy
│   │   │   ├── email/        # Gmail integration + AI scan
│   │   │   └── onboarding/   # New user setup
│   │   ├── dashboard/        # Protected pages (jobs, tracker, inbox, profile)
│   │   ├── login/            # OAuth sign-in/sign-up
│   │   └── onboarding/       # Multi-step profile setup
│   ├── components/           # Sidebar, filters, editors, notifications
│   ├── context/              # AI agent + application state
│   └── lib/                  # MongoDB, Gemini, OpenRouter clients
└── package.json

docs/                         # Project documentation
└── devpost.md                # Hackathon submission writeup

Setup

1. Web Dashboard

cd web
npm install

Create web/.env.local:

GOOGLE_CLIENT_ID=your_google_client_id
GOOGLE_CLIENT_SECRET=your_google_client_secret
NEXTAUTH_SECRET=your_nextauth_secret
NEXTAUTH_URL=http://localhost:3000
MONGODB_URI=your_mongodb_connection_string
MONGODB_DB=jaidb
GOOGLE_API_KEY=your_gemini_api_key
OPENROUTER_API_KEY=your_openrouter_api_key    # Optional — fallback model provider
RAPIDAPI_KEY=your_rapidapi_key                # Optional — for JSearch job listings

npm run dev
# Dashboard at http://localhost:3000

2. Chrome Extension

Create extension/scripts/config.js (gitignored):

const JAI_CONFIG = {
    API_KEYS: [
        "YOUR_GEMINI_API_KEY_1",    // Optional — leave empty if using OpenRouter only
        "YOUR_GEMINI_API_KEY_2"     // Optional rotation key
    ],
    OPENROUTER_KEY: "YOUR_OPENROUTER_KEY"  // Free fallback — get one at openrouter.ai (no credit card)
};

Load in Chrome:

1. Navigate to chrome://extensions
2. Enable Developer mode
3. Click Load unpacked → select the extension/ folder

Usage

1. Login — Open http://localhost:3000 and sign in with Google. Complete the onboarding profile.
2. Configure Resume — Open the extension settings and paste your LaTeX resume (a default template is pre-loaded).
3. Optimize — Navigate to a job posting, open the JAI side panel, and click Generate & Download PDF. The extension extracts the JD, sends it to Gemini, and opens Overleaf with the tailored LaTeX.
4. Autofill — On any job application form, click Autofill Application to auto-fill form fields from your profile.

Tech Stack

Layer	Technologies
Extension	Chrome Manifest V3, Service Workers, Content Scripts
Frontend	Next.js 16, React 19, Tailwind CSS 4, Heroicons
Backend	Next.js API Routes (serverless), NextAuth
AI	Google Gemini 2.0 Flash, OpenRouter (fallback)
Database	MongoDB Atlas
Auth	Google OAuth 2.0, NextAuth.js
PDF	Overleaf (LaTeX compilation)
Jobs API	JSearch via RapidAPI

AI Provider Fallback

JAI automatically falls back through available AI providers:

Priority	Provider	Requirement	Quality
1st	Google Gemini	GOOGLE_API_KEY	Best — full AI rewrite, PDF support
2nd	OpenRouter (paid)	OPENROUTER_API_KEY	Excellent — Gemini 2.0 Flash via API
3rd	OpenRouter (free)	Same key, no credit card	Great — Llama 3.3 70B, rate-limited
4th	Local NLP Engine	Nothing — built in	Good — TF-IDF keywords, skill injection, bullet enhancement

The local NLP engine runs with zero API keys and zero internet. It uses TF-IDF keyword extraction to identify important JD terms, detects skills mentioned in the JD but missing from your resume, strengthens weak action verbs, and injects relevant skills into your Skills section.

For the best experience, configure at least a free OpenRouter key. But the app works completely offline as a last resort.

Troubleshooting

• Extension not connecting — Make sure the web app is running on localhost:3000 and you're logged in. The extension detects the session via cookies.
• Overleaf not pasting — Click the JAI status banner in the Overleaf tab to re-copy the LaTeX to your clipboard, then paste manually with Ctrl+V.
• Gemini 429 errors — Add a second API key in config.js for automatic rotation. The extension retries with countdown on quota exhaustion.
• No API key at all — Set OPENROUTER_KEY in config.js (extension) or OPENROUTER_API_KEY in .env.local (web). Free models work with no credit card.