Chain integration

How to implement Sybil Resistance in your app on Ontology EVM?

Humanode Core

31 Jul 2025 • 2 min read

Ontology is a public blockchain focused on secure identity, data privacy, and user control. With ONT ID, ONTO Wallet, and Orange Protocol, Ontology gives Web3 projects self-sovereign tools like DIDs and zero-knowledge proofs; no tracking, no middlemen, just people in control. As the Ontology ecosystem grows, Sybil attacks and bot abuse are constant headaches for builders in DeFi, rewards, and governance protocols.

Humanode Biomapper is now available on Ontology EVM, bringing a privacy-preserving, biometric-based Sybil resistance layer that can be integrated into any dApp. Biomapper ensures every interaction comes from a real, unique human - no KYC, no personal data exposure.

Key Concepts

Generations: User uniqueness is verified for a limited period (“generation”), after which re-verification is required.
Integration Flow: Users verify once, bridge their uniqueness proof to the Ontology EVM, and can use that across all compatible dApps.

Step-by-Step Integration Guide

1. Install Biomapper SDK

Add the necessary packages to your project:

npm install --save @biomapper-sdk/core @biomapper-sdk/libraries @biomapper-sdk/events

# or

yarn add @biomapper-sdk/core @biomapper-sdk/libraries @biomapper-sdk/events

For Foundry users:

forge install humanode-network/biomapper-sdk

2. Import Biomapper Interface

In your Solidity smart contract, add:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { IBridgedBiomapperRead } from "@biomapper-sdk/core/IBridgedBiomapperRead.sol";

3. Connect to the Bridged Biomapper Contract

The Biomapper contract is deployed on Ontology EVM. Connect using the contract address.

4. Add Biomapper UI Link for Users

Let users complete uniqueness verification through the Biomapper app:

< a href="https://biomapper.hmnd.app" target="_blank">Verify Uniqueness< / a>

After verification, users can return and interact with your dApp.

5. (Optional) Local Testing

Use the MockBridgedBiomapper contract from the SDK for local testing. See the SDK docs for setup and usage.

6. Deploy Your dApp

Deploy your contract on Ontology EVM (mainnet or testnet).
Use the correct BridgedBiomapper contract address for Ontology.
Link your frontend to the Biomapper UI for user onboarding.

Resources

Biomapper App: https://biomapper.hmnd.app
Docs: https://link.humanode.io/docs/biomapper
SDK: https://link.humanode.io/docs/biomapper-sdk
Integration Guide: https://link.humanode.io/docs/biomapper/integration/chains/ontology

By integrating Biomapper with your Ontology EVM dApp, you add Sybil resistance, enable fair access, and protect your platform from bots while keeping user data private and the onboarding process simple.

Need help? Join the Humanode Discord or refer to the documentation.