StarDust Backend

AI-powered conversational backend built with FastAPI, LangGraph, Gemini, and Tavily Search.

StarDust provides an agentic chat experience capable of maintaining conversation history, performing web searches, and offering coding guidance through an integrated LeetCode coach tool.

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Features

• Streaming AI responses
• Multi-turn conversations
• Persistent chat memory
• Web Search via Tavily
• LeetCode AI Coach
• Gemini 2.5 Flash integration
• LangGraph-based agent workflow
• FastAPI backend
• Server-Sent Events (SSE) support

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Architecture

User Query ↓

FastAPI Endpoint

↓

LangGraph Agent

↓

Gemini 2.5 Flash

↓

Tool Calling

├── Tavily Search

└── LeetCode AI Coach

↓

Streaming Response

↓

Frontend

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Tech Stack

Component	Technology
Backend	FastAPI
LLM	Gemini 2.5 Flash
Agent Framework	LangGraph
Search	Tavily API
Memory	LangGraph MemorySaver
Environment	python-dotenv
Streaming	SSE

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Installation

Clone repository

git clone https://github.com/yourusername/StarDust_Backend.git

cd StarDust_Backend

Install dependencies

pip install -r requirements.txt

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Environment Variables

Create a .env file.

GOOGLE_API_KEY=YOUR_KEY

TAVILY_API_KEY=YOUR_KEY

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Running the Server

uvicorn app:app --reload

Server runs at

http://localhost:8000

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API Endpoints

Health Check

GET /

Response

{
"status":"Backend running"
}

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Chat Streaming

GET /chat_stream/{message}

Optional

checkpoint_id

Example

/chat_stream/Explain Binary Search

Returns streamed responses.

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Built-in Tools

Tavily Search

Allows the assistant to search the web.

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LeetCode AI Coach

Generates:

• Step-by-step approach
• Optimized solution
• Complexity analysis
• Edge cases
• Key insights

Example

Two Sum Problem

Output includes:

• Explanation
• Code
• Complexity
• Tips

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Deployment

Compatible with:

• Render
• Railway
• Fly.io
• Docker

A Render deployment configuration is included.

render.yaml

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Future Improvements

• RAG Integration
• Document Upload Support
• Voice Conversations
• Authentication
• Multiple LLM Providers
• Tool Marketplace

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License

MIT License