Inspiration

We were inspired by the enormous problem of global food waste.
According to the UN, about 1.3 billion tons of food are wasted each year, creating nearly 8–10% of global greenhouse gas emissions. We wanted to build something that helps people reduce food waste at home and make sustainable food choices easier.

What it does

Smart Fridge is a web application that:

  • Accepts multiple photos of a fridge or pantry.
  • Uses AWS Rekognition to detect and normalize ingredients into a clean inventory list.
  • Prompts for the number of people you’re cooking for and uses an AI agent (OpenAI GPT-4o) to generate recipes with the ingredients you already have.
  • Scores each ingredient’s carbon footprint using a curated dataset and highlights high-impact foods like beef.
  • Suggests low-carbon swaps and calculates a household sustainability score to guide future shopping decisions.

How we built it

Before coding, we created a logical flow chart to map the process:
Image Upload → Ingredient Detection → Inventory Merge → Carbon Scoring → AI Recipe Generation.

Tech Stack:

  • Frontend: Next.js + Tailwind for a responsive UI with multi-image upload and results display.
  • Backend: FastAPI for REST endpoints, orchestration, and data validation.
  • Image Analysis: AWS Rekognition for food detection and RapidFuzz for label normalization.
  • AI Agent: OpenAI GPT-4o mini for recipe generation and sustainability suggestions.
  • Data: Custom JSON mapping ingredients to their CO₂e (kg per 100 g) and sustainability tags.
  • Deployment: Frontend on Vercel, Backend on Render.

We divided the work into four key areas:
Frontend UI, Vision Service (Rekognition + normalization), Planner & Carbon Engine, and Recipe Service (LLM integration with strict JSON schema).

Challenges we ran into

  • AI Tuning: Ensuring the AI only generated recipes using the detected ingredients required strict JSON schemas and careful prompt engineering.
  • Merge Conflicts: With four beginners collaborating, Git merge conflicts were frequent and required quick resolution.
  • Feature Scope: We debated which features to prioritize, balancing time constraints with our sustainability focus.
  • API Limits & Latency: Managing Rekognition calls and OpenAI token limits while keeping response times short.

Accomplishments that we're proud of

  • Building a fully working end-to-end system in under 24 hours.
  • Designing a clean architecture that integrates computer vision, carbon scoring, and an AI recipe generator.
  • Creating a simple but effective carbon impact scoring system with actionable low-carbon swap suggestions.
  • Learning how to collaborate efficiently with Git despite frequent conflicts.

What we learned

  • How to design and deploy a multi-service architecture combining real-time image analysis and AI.
  • Effective Git collaboration with branching, pull requests, and conflict resolution.
  • Prompt engineering and how to enforce structured JSON output from large language models.
  • The importance of clear, impactful sustainability metrics that motivate users to act.

What's next for Smart Fridge

  • Automatic Expiration Detection: Use computer vision to estimate expiration dates and alert users.
  • Personal Sustainability Goals: Let users set targets (e.g., reduce carbon footprint by X% over time).
  • Community Features: Integrate with local food donation or composting resources to help people keep food out of landfills.
  • Enhanced Recipe Engine: Add filters for nutrition, allergy preferences, or regional cuisines.

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