📧 Email Writer SB — Spring Boot + Groq API

A Spring Boot application that generates professional email replies using Groq's LLM models with failover support.
The service takes an input email and optional tone, then uses the Groq API to produce a natural, contextually relevant reply.

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🚀 Features

• Multi-model failover — Try multiple Groq models in priority order until one succeeds.
• Customizable tone — Choose between professional, casual, friendly, etc.
• Simple REST API — Easy to integrate with any frontend or automation pipeline.
• Environment-based configuration — Secure API keys via environment variables.

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🛠️ Tech Stack

• Java 17+
• Spring Boot
• WebClient (Spring WebFlux) for non-blocking API calls
• Groq API for LLM responses
• Jackson for JSON parsing

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📂 Project Structure

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⚙️ Configuration

Edit application.properties (or use environment variables):

spring.application.name=email-writer-sb

# Groq settings
groq.api.url=${GROQ_URI}
groq.api.key=${GROQ_KEY}

# Comma-separated models in priority order
groq.models=meta-llama/llama-4-scout-17b-16e-instruct,llama3-70b-8192,mixtral-8x7b-32768,gemma2-9b-it


Environment Variables:
export GROQ_URI="https://api.groq.com/openai/v1/chat/completions"
export GROQ_KEY="your_api_key_here"


▶️ Running the Project
With Maven
mvn spring-boot:run

With JAR
mvn clean package
java -jar target/email-writer-sb-0.0.1-SNAPSHOT.jar


📬 API Usage

Endpoint:
POST /generate-email-reply

Request Body:
{
  "emailContent": "Hi team, I wanted to follow up on the proposal I sent last week. Can you provide an update?",
  "tone": "professional"
}

Response Example:
{
  "reply": "Hello, thank you for following up. We are currently reviewing your proposal and will get back to you by the end of the week."
}

🧪 Testing with Postman

1.Open Postman

2. Create a new POST request:
http://localhost:8080/generate-email-reply

3. Set header:
Content-Type: application/json

4. Add body (raw → JSON):
{
  "emailContent": "Thanks for the meeting yesterday. Can you send me the final report?",
  "tone": "friendly"
}

🔄 Sequence Diagram
sequenceDiagram
    autonumber
    participant Client as Client App / Postman
    participant API as EmailController (Spring Boot)
    participant Service as EmailGeneratorService
    participant Groq as Groq API

    Client->>API: POST /generate-email-reply (emailContent, tone)
    API->>Service: processRequest()
    Service->>Groq: POST /chat/completions (model, prompt)
    Groq-->>Service: AI-generated email reply
    Service-->>API: return generated reply
    API-->>Client: JSON { reply: "...email text..." }


📄 License

MIT License.