Smart Email Summarizer

A Spring Boot application that uses Spring AI 1.0.0 and OpenAI to intelligently summarize email content with configurable prompt templates.

Features

• Configurable Prompts: Easily customizable prompt templates
• REST API: Simple HTTP endpoints for email summarization
• Validation: Input validation for email content
• Structured Format: All summaries formatted with "Summary:" header and bullet points

Technology Stack

• Spring Boot 3.5.0
• Spring AI 1.0.0
• OpenAI GPT-4o-mini
• Java 21
• Maven

Project Structure

smart-email-summarizer/
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── com.example.emailsummarizer/
│   │   │       ├── controller/
│   │   │       │   └── EmailSummarizerController.java
│   │   │       ├── config/
│   │   │       │   └── PromptConfig.java
│   │   │       ├── model/
│   │   │       │   └── EmailRequest.java
│   │   │       └── EmailSummarizerApplication.java
│   │   └── resources/
│   │       └── application.yml
└── pom.xml

Major Changes in Spring AI 1.0.0

1. ChatClient API: New fluent ChatClient.Builder pattern replaces the old ChatClient
2. Message Structure: Updated to use UserMessage classes
3. Prompt Building: Enhanced Prompt class with List of messages
4. Method Chaining: New fluent API with .prompt().call().content() pattern
5. Spring Boot 3.3.0: Updated to latest Spring Boot version
6. Java 21: Updated to use Java 21 for better performance
7. GPT-4o-mini: Updated to use the latest OpenAI model

Setup Instructions

Prerequisites

1. Java 21 or higher
2. Maven 3.8+
3. OpenAI API Key

Installation

1. Clone the repository

   git clone <repository-url>
   cd smart-email-summarizer

2. Set up OpenAI API Key

   Option 1: Environment Variable

   export OPENAI_API_KEY=your-actual-openai-api-key

   Option 2: Update application.yml

   spring:
     ai:
       openai:
         api-key: your-actual-openai-api-key

3. Build the project

   mvn clean install

4. Run the application

   mvn spring-boot:run

The application will start on http://localhost:8080

API Endpoints

1. Summarize Email (Full Options)

POST /api/email/summarize

Request Body:

{
  "subject": "Q2 Revenue Forecast",
  "from": "[email protected]",
  "content": "Hi team, please find attached the latest projections for Q2. Revenue is expected to increase by 15% compared to Q1...",
}

Parameters:

• subject (required): Email subject line
• from (required): Sender's email address
• content (required): The email content to summarize

Response:

{
  "summary": "Summary:\n• CEO shared Q2 revenue forecast\n• Projections indicate 15% growth compared to Q1\n• Detailed projections attached in document",
  "subject": "Q2 Revenue Forecast",
  "from": "[email protected]"
}

Usage Examples

Example 1: Summary

curl -X POST http://localhost:8080/api/email/summarize \
  -H "Content-Type: application/json" \
  -d '{
    "subject": "Q4 Budget Review",
    "from": "[email protected]",
    "content": "The Q4 budget review meeting is scheduled for next Friday at 2 PM. Please prepare your department budgets and expense reports. We need to finalize the numbers before the board meeting on Monday."
  }

Configuration

OpenAI Configuration

Customize OpenAI settings in application.yml:

spring:
  ai:
    openai:
      api-key: ${OPENAI_API_KEY}
      chat:
        options:
          model: gpt-4o-mini          # Latest OpenAI model
          temperature: 0.3            # Creativity level (0.0-1.0)
          max-tokens: 1000           # Response length limit
      base-url: https://api.openai.com

Available Models

• gpt-4o-mini (recommended for cost efficiency)
• gpt-4o
• gpt-4-turbo
• gpt-3.5-turbo

Spring AI 1.0.0 Migration Notes

Key API Changes:

1. ChatClient Injection:

   @Autowired
   public EmailSummarizerController(ChatClient.Builder chatClientBuilder, PromptConfig promptConfig) {
       this.chatClient = chatClientBuilder.build();
   }

2. Message Creation:

   Message userMessage = userPromptTemplate.createMessage(variables);
   Prompt prompt = new Prompt(List.of(userMessage));

3. Chat Invocation:

   String summary = chatClient.prompt(prompt).call().content();

Development

Building for Production

mvn clean package
java -jar target/smart-email-summarizer-0.0.1-SNAPSHOT.jar

Testing

Run tests with:

mvn test

Troubleshooting

Common Issues

1. Spring AI 1.0.0 Compatibility

   • Ensure you're using Spring Boot 3.3.0+
   • Java 21 is recommended for optimal performance

2. OpenAI API Key Error

   • Verify your API key is valid and has sufficient credits
   • Check environment variable or application.yml configuration

3. Model Availability

   • GPT-4o-mini is the default model for cost efficiency
   • Switch to GPT-4o for enhanced capabilities if needed

License

This project is licensed under the MIT License. Organized list format

• Priority Modifiers: Additional context for high/low priority emails

OpenAI Configuration

Customize OpenAI settings in application.yml:

spring:
  ai:
    openai:
      api-key: ${OPENAI_API_KEY}
      chat:
        options:
          model: gpt-3.5-turbo        # or gpt-4
          temperature: 0.3            # creativity level (0.0-1.0)
          max-tokens: 1000           # response length limit

Testing

Run tests with:

mvn test

Building for Production

mvn clean package
java -jar target/smart-email-summarizer-0.0.1-SNAPSHOT.jar

Troubleshooting

Common Issues

1. OpenAI API Key Error

   • Ensure your API key is valid and has sufficient credits
   • Check environment variable or application.yml configuration

2. Connection Timeout

   • Verify internet connection
   • Check OpenAI service status

3. Invalid Request Format

   • Ensure JSON is properly formatted
   • Check required fields are present

Logs

Application logs are written to:

• Console output
• logs/email-summarizer.log file

License

This project is licensed under the MIT License.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Support

For issues and questions, please create an issue in the repository or contact the owner.