KYC-Free Identity Verification with Blockchain and AI Agents

Traditional Know Your Customer (KYC) processes are invasive, slow, and centralized. But what if users could prove their humanness and identity using biometrics without handing over sensitive documents? In this blog, we'll build a KYC-Free Identity Verification System using AI agents and blockchain smart contracts.

Why Go KYC-Free?

In decentralized apps (dApps), verifying users without centralized control is challenging. KYC-free systems enable:

• Privacy-preserving identity
• Scam and bot prevention
• Reusable credentials across platforms

How It Works

The user speaks a random phrase while moving their face. An AI agent verifies both voice and facial movement. If valid, a smart contract issues a non-transferable NFT as proof of humanity.

Tech Stack

• Frontend: React + MetaMask Wallet Integration
• Backend: FastAPI for AI verification
• AI Models: dlib (facial landmarks), Google Speech API (voice match)
• Blockchain: Solidity Smart Contract deployed on Sepolia Testnet

Project Structure

project/
├── backend/            # FastAPI for verification
│   ├── main.py
│   ├── verification.py
│   └── utils/
├── frontend/           # React + Wallet Connect
│   ├── public/
│   └── src/
├── contracts/
│   └── HumanProofSBT.sol

Smart Contract

The HumanProofSBT contract issues a Soulbound Token (SBT) if verification passes. It prevents duplicate claims and stores user status immutably.

Voice & Face Verification

The backend uses:

• dlib: for detecting facial movements
• Google Cloud Speech-to-Text: for validating spoken phrase

Errors like >“Unable to open shape_predictor_68_face_landmarks.dat” indicate missing model files. Ensure the .dat file is present in your project and correctly referenced in your code. On mobile or small screens, check your file paths and permissions if you encounter this error.

Handling CORS & API Errors

For your React app to communicate with FastAPI, set proper CORS headers:

from fastapi.middleware.cors import CORSMiddleware
app.add_middleware(
  CORSMiddleware,
  allow_origins=["http://localhost:3000"],
  allow_methods=["*"],
  allow_headers=["*"],
)

Final Touch: MetaMask + UI

Once verified, the user can connect their wallet and claim a proof NFT. If already verified, show a badge and skip re-verification.

Source Code

You can explore the full source code and try it yourself via GitHub:

🔗 github.com/nipunbandara/Identity-Verifier

Conclusion

This KYC-Free identity system proves how AI and blockchain can work together to replace centralized verification. You preserve privacy while offering strong proof of personhood—ideal for Web3 platforms, DAOs, and more.