Walmart Sparkathon 2025: Edot & Smart Tax System

Overview

This project is a comprehensive solution built for Walmart Sparkathon 2025. It comprises two key modules:

1. Edot — a sustainability tracker for Walmart products, providing customers with real-time insights into a product's carbon footprint.
2. Smart Tax — a blockchain-powered logistics and tax management system that automates GST/VAT computation, return handling, and real-time financial forecasting.

Our solution integrates cutting-edge technology including blockchain, reinforcement learning (RL), smart contracts, and real-time compliance engines to create a transparent, automated, and eco-conscious retail logistics platform.

---

Features

Edot (Sustainability Tracker)

• Calculates carbon footprint during product manufacturing and transportation.
• Displays sustainability metrics at checkout for informed consumer decisions.
• Integrated with the Walmart supply chain to fetch and analyze emissions data.
• Supports product-level carbon impact estimation using Climatiq API.

Smart Tax

• Automates GST/VAT computation using blockchain and smart contracts.
• Provides real-time net payout and tax liability previews.
• Generates immutable audit logs accessible to both sellers and regulators.
• Integrated with Walmart's logistics and financial systems.

---

System Architecture

1. Blockchain-Powered Return Passport

• ReturnPassport and EmissionContract deployed on Ethereum L2 (e.g., Arbitrum).
• Each shipment gets a Logistics Passport NFT capturing audit trail, fees, taxes, and compliance events.

2. RL-Driven Returns Optimization Engine

• Trained on historical returns data.
• Routes returns to restock, refurbish, donate, or scrap, maximizing economic and environmental value.

3. Gamified Customer Experience

• Loyalty rewards, NFTs, and impact dashboards incentivize eco-friendly returns.

4. Compliance & Automation

• Real-time warehouse insights (via IoT) drive automated restocking and refund decisions.

5. Offline Retail Integration

• Smart return kiosks with blockchain verification.
• Digital receipts replacing traditional paper-based returns.

---

Technology Stack

• Blockchain: Ethereum L2 (Arbitrum)
• RL Engine: PyTorch + RLlib
• Frontend: React + WalletConnect
• Backend: Node.js / Python (microservices)
• Smart Contracts: Solidity
• Data Storage: IPFS, blockchain logs
• Cloud Services: AWS Lambda, Firebase (for real-time dashboards)
• Emissions API: Climatiq API

---

Edot — Sustainability Measurement

Key Capabilities

• Tracks product-specific CO2 emissions during manufacturing and logistics.

• Quantifies environmental impact using on-chain EmissionContract.

• Displays “CO2 Saved” stats on user dashboards.

• Climatiq API Integration:

  • Provides emission estimates based on:

    • Type: Spend-Based
    • Country
    • Product Category & Subcategory
    • Amount Spent

  • Also supports estimation of intermodal freight emissions.

  • Reference: Climatiq Data Explorer

---

Smart Tax System

Marketplace Tax Classifications

• W-9: U.S.-based sellers with EIN.
• W-8ECI / W-8BEN-E / W-8BEN: For non-U.S. sellers depending on their structure.
• India-specific docs: GST Certificate, utility bills, MSME certificate, Shop License, etc.

Tax Code Management

• Sellers assign shipping sales tax codes via Walmart Seller Center.
• Enables accurate tax collection for local compliance.

WFS Fees Breakdown (April 2025)

• Fulfillment, return, storage, disposal, and problem inventory fees tiered by weight, category, and handling.
• Optional programs include multi-box, prep services, cross-border imports, serial collection, and more.

Logistics Passport NFT Structure

Each passport NFT includes:

• Identifiers: passportId, shipmentId, sellerId
• Product Info: itemSKUs[], unitType
• Compliance: labelCheck, packagingCheck, palletCheck
• Financials: fulfillmentFee, storageFee, returnProcessingFee, saleTaxRate, refundAmount, netPayout
• Lifecycle Status: CREATED → RECEIVED → READY_FOR_SALE → RETURN_REQUESTED → ROUTED → SETTLED

Workflow Events

• ShipmentCreated, LabelVerified, PackagingVerified, PalletVerified, FeesCalculated, ReturnRequested, ConditionGraded, RouteReturn, TaxSettlement, PayoutExecuted

Smart-Tax Contract Logic

• Records WFS fees and tax rates.
• Computes refundAmount, refundTax, netPayout for each return.
• Emits PayoutReady for final settlement.

solidity contract SmartTax { function recordFees(...); function settleReturn(...) { refundAmt = saleAmount * restockPct / 100; refundTax = refundAmt * saleTaxRate / 100; net = refundAmt - refundTax - returnFee; emit PayoutReady(...); } }

Benefits

• End-to-end fee/tax traceability.
• Regulatory audit-readiness.
• Eliminates spreadsheets/manual reconciliation.
• Enables real-time insights for logistics and finance teams.

---

Pipeline Management

1. Blockchain Return Passport

• On chain records of ownership, emissions, returns.
• Smart contracts manage refunds, tax adjustments.

2. RL-Driven Optimization

• RL agents auto-route returns based on resale probability and cost.
• Smart contracts execute actions like restock() or donate().

3. Gamified Experience

• NFTs for eco-friendly actions.
• Customer dashboard tracks CO₂ savings and impact.

4. Compliance Automation

• IoT linked warehouse sensors update return pipeline.
• Regulator queries enabled via getReturnAudit().

5. Offline Integration

• QR powered kiosks with blockchain verification.
• Paperless receipts and wallet-linked returns.

---

Contact

For questions, feedback, or contributions:

• Team: Kurnool ke Karamchari
• Hackathon: Walmart Sparkathon 2025