Knoxify - Text to Speech Web Application

A modern web application that converts text files to natural-sounding speech using AWS Polly. Upload a .txt file, select a voice, and download the generated MP3 audio.

Features

• 📄 Upload .txt files (max 50 KB)
• 🎙️ Choose from 8 AI voices (Joanna, Matthew, Ivy, Kendra, etc.)
• ⚡ Automatic text-to-speech conversion via AWS Lambda
• 🎧 Play and download generated MP3 audio
• 🌙 Clean dark theme UI

Architecture

┌─────────────┐     ┌──────────────────┐     ┌─────────────────┐
│   Browser   │────▶│   Flask App      │────▶│  S3 Source      │
│             │     │   (Python)       │     │  Bucket         │
└─────────────┘     └──────────────────┘     └────────┬────────┘
                                                      │
                                                      ▼ (S3 Trigger)
┌─────────────┐     ┌──────────────────┐     ┌─────────────────┐
│   Browser   │◀────│  Pre-signed URL  │◀────│  Lambda + Polly │
│  (Download) │     │                  │     │                 │
└─────────────┘     └──────────────────┘     └────────┬────────┘
                                                      │
                                                      ▼
                                             ┌─────────────────┐
                                             │  S3 Destination │
                                             │  Bucket (.mp3)  │
                                             └─────────────────┘

Project Structure

Knoxify/
├── app.py                 # Flask backend
├── lambda_function.py     # AWS Lambda function code
├── requirements.txt       # Python dependencies
├── .env                   # Environment variables (not in repo)
├── .gitignore
├── templates/
│   └── index.html         # Main UI template
├── static/
│   ├── css/style.css      # Dark theme styles
│   └── js/main.js         # Frontend logic
└── README.md

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AWS Setup Guide

Prerequisites

• AWS Account
• AWS CLI configured (optional)

Step 1: Select AWS Region

Set your region to us-east-1 (N. Virginia) for all resources.

---

Step 2: Create S3 Buckets

Source Bucket (for uploaded text files)

1. Go to S3 → Create bucket
2. Name: knoxify-source-bucket
3. Region: us-east-1
4. Keep Block all public access enabled
5. Click Create bucket

Destination Bucket (for generated audio)

1. Go to S3 → Create bucket
2. Name: knoxify-destination-bucket
3. Region: us-east-1
4. Keep Block all public access enabled
5. Click Create bucket

---

Step 3: Create IAM Policy

1. Go to IAM → Policies → Create policy
2. Click JSON tab and paste:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["s3:GetObject", "s3:PutObject"],
      "Resource": [
        "arn:aws:s3:::knoxify-source-bucket/*",
        "arn:aws:s3:::knoxify-destination-bucket/*"
      ]
    },
    {
      "Effect": "Allow",
      "Action": ["polly:SynthesizeSpeech"],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "logs:CreateLogGroup",
        "logs:CreateLogStream",
        "logs:PutLogEvents"
      ],
      "Resource": "arn:aws:logs:*:*:*"
    }
  ]
}

3. Name: KnoxifyLambdaPolicy
4. Click Create policy

---

Step 4: Create IAM Role for Lambda

1. Go to IAM → Roles → Create role
2. Trusted entity: AWS service
3. Use case: Lambda
4. Attach policy: KnoxifyLambdaPolicy
5. Name: knoxify-lambda-role
6. Click Create role

---

Step 5: Create Lambda Function

1. Go to Lambda → Create function
2. Function name: knoxify-text-to-speech
3. Runtime: Python 3.9
4. Execution role: Use existing role → knoxify-lambda-role
5. Click Create function

Add Environment Variable

1. Go to Configuration → Environment variables
2. Add:
   • Key: DESTINATION_BUCKET
   • Value: knoxify-destination-bucket

Upload Code

1. Copy the contents of lambda_function.py from this repo
2. Paste into the Lambda code editor
3. Click Deploy

Configure Timeout

1. Go to Configuration → General configuration
2. Set timeout to 30 seconds

---

Step 6: Add S3 Trigger

1. In Lambda → Configuration → Triggers
2. Click Add trigger
3. Select S3
4. Bucket: knoxify-source-bucket
5. Event type: PUT
6. Suffix: .txt
7. Click Add

---

Step 7: Create IAM User for Web App

1. Go to IAM → Users → Create user
2. Name: knoxify-app-user
3. Click Next
4. Select Attach policies directly
5. Attach:
   • AmazonS3FullAccess
   • AmazonPollyFullAccess
6. Click Create user

Generate Access Keys

1. Select the user → Security credentials tab
2. Click Create access key
3. Select Application running outside AWS
4. Save the Access Key ID and Secret Access Key

---

Local Setup

1. Clone the Repository

git clone https://github.com/Rupeshs11/Knoxify.git
cd Knoxify

2. Create Virtual Environment

python -m venv venv

# Windows
venv\Scripts\activate

# macOS/Linux
source venv/bin/activate

3. Install Dependencies

pip install -r requirements.txt

4. Configure Environment Variables

Create a .env file in the project root:

AWS_ACCESS_KEY_ID=your_access_key_here
AWS_SECRET_ACCESS_KEY=your_secret_key_here
AWS_REGION=us-east-1

SOURCE_BUCKET=knoxify-source-bucket
DESTINATION_BUCKET=knoxify-destination-bucket

SECRET_KEY=your-flask-secret-key

5. Run the Application

python app.py

Open your browser to http://localhost:5000

---

API Endpoints

Endpoint	Method	Description
/	GET	Homepage
/upload	POST	Upload text file + voice
/status/<job_id>	GET	Check processing status
/download/<job_id>	GET	Download audio (pre-signed URL)
/voices	GET	List available voices

---

Available Voices

Voice	Gender	Accent
Joanna	Female	US English
Matthew	Male	US English
Ivy	Female	US English (Child)
Kendra	Female	US English
Salli	Female	US English
Joey	Male	US English
Justin	Male	US English (Child)
Kevin	Male	US English (Child)

---

Tech Stack

• Frontend: HTML, CSS, JavaScript (Vanilla)
• Backend: Python, Flask
• Cloud: AWS S3, Lambda, Polly
• Auth: AWS IAM, Pre-signed URLs