Reply Nexa ✉️

AI-powered email reply generator — paste an email, pick your tone and language, get a polished reply in seconds.

Built with Streamlit + Google Gemini API, featuring real SMTP email sending and multi-language support.

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✨ Features

• AI Reply Generation — Gemini drafts context-aware, professional replies to any email
• 5 Tone Modes — Professional · Friendly · Apologetic · Persuasive · Concise
• 24+ Language Support — Generate replies in English, Hindi, Spanish, French, Arabic, Japanese, and more
• Edit Before Send — Review and tweak the AI reply before it goes out
• One-Click Send — Built-in SMTP integration to send directly from the app
• Free-Tier Smart Fallback — Automatically cycles through Gemini models to stay within quota limits
• Fully Responsive UI — Dark cyberpunk theme with green accent, works on desktop & mobile

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🗂️ Project Structure

reply-nexa/
├── main.py                  # Streamlit app entry point
├── requirements.txt         # Python dependencies
├── agents/
│   └── email_agent.py       # Gemini AI reply generation logic
└── utils/
    └── email_sender.py      # SMTP email sending utility

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🚀 Getting Started

1. Clone the repository

git clone https://github.com/your-username/reply-nexa.git
cd reply-nexa

2. Install dependencies

pip install -r requirements.txt

3. Configure secrets

Create a .streamlit/secrets.toml file:

GEMINI_API_KEY = "your-google-gemini-api-key"
SENDER_EMAIL   = "your-gmail@gmail.com"
EMAIL_PASSWORD = "your-gmail-app-password"

# Optional — defaults shown
SMTP_SERVER = "smtp.gmail.com"
SMTP_PORT   = 587

Gmail users: Generate an App Password (requires 2FA enabled). Do not use your regular Gmail password.

4. Run the app

streamlit run main.py

Open http://localhost:8501 in your browser.

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🔑 Getting a Gemini API Key

1. Go to Google AI Studio
2. Sign in with your Google account
3. Click Get API key → Create API key
4. Copy the key into your secrets.toml

The app uses free-tier Gemini models with automatic fallback:

Model	Daily Quota
gemini-2.5-flash-lite	1,000 req/day (primary)
gemini-2.5-flash	250 req/day
gemini-2.0-flash-lite	fallback
gemini-2.0-flash	last resort

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🌐 Deploying to Streamlit Cloud

1. Push your code to a public or private GitHub repo
2. Go to share.streamlit.io → New app
3. Select your repo, branch, and set main.py as the entry file
4. Under Advanced settings → Secrets, paste your secrets.toml contents
5. Click Deploy

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🌍 Supported Languages

English · Hindi · Spanish · French · German · Portuguese · Arabic · Japanese · Chinese (Simplified) · Korean · Italian · Russian · Bengali · Gujarati · Marathi · Tamil · Telugu · Kannada · Punjabi · Dutch · Polish · Turkish · Vietnamese · Thai

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🛠️ Tech Stack

Layer	Technology
Frontend	Streamlit
AI Model	Google Gemini (via google-generativeai)
Email	Python smtplib + MIME
Styling	Custom CSS (Bebas Neue · DM Sans · JetBrains Mono)

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📋 Usage

1. Paste the email you received into the text area
2. Select your desired tone (Professional, Friendly, etc.)
3. Choose the language for your reply
4. (Optional) Enter a recipient email and any extra instructions
5. Click ⚡ GENERATE REPLY
6. Review and edit the generated reply
7. Click SEND EMAIL to send, or COPY TO CLIPBOARD to use elsewhere

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⚠️ Troubleshooting

Generation failed / quota error

Wait a few minutes and retry. The app will automatically try the next available Gemini model. Check your quota at aistudio.google.com.

SMTP / sending failed

Ensure you're using a Gmail App Password, not your account password. Verify SENDER_EMAIL, EMAIL_PASSWORD, SMTP_SERVER, and SMTP_PORT in your secrets.

Secrets not found (local)

Make sure .streamlit/secrets.toml exists at the project root and is correctly formatted TOML.

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📄 License

All Rights Reserved © 2026 Ravi Panchal

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Made with ❤️ by Ravi Panchal