Biomapper

How to add Sybil resistance to your dApp on XRPL EVM sidechain?

Humanode Core

14 Aug 2025 • 2 min read

XRPL EVM Sidechain brings EVM-compatible dApps to a chain connected to XRPL, using XRP as gas for fast, low-cost transactions. As new apps roll out, stopping Sybil attacks and bot abuse is essential for fair rewards, governance, and user interactions.

Humanode Biomapper is now available on the XRPL EVM Sidechain, adding a privacy-preserving, biometric-based Sybil resistance layer you can plug into any dApp. Biomapper ensures each participating address maps to a real, unique human; no KYC, no PII.

Key Concepts

Generations: User uniqueness is valid for a limited period (“generation”); re-verification is required afterward.
Integration Flow: Users verify once, bridge their uniqueness proof to XRPL EVM, and use it across compatible dApps.

Step-by-Step Integration Guide

1) Install Biomapper SDK

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:

forge install humanode-network/biomapper-sdk

2) Import Biomapper Interface

In your Solidity contract:

// 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 the XRPL EVM Sidechain. Connect using the contract address.

4) Add Biomapper UI Link (Frontend)

Send users to complete uniqueness verification:

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

After verification, users return to your dApp and interact normally.

5) (Optional) Local Testing

Use MockBridgedBiomapper from the SDK to simulate uniqueness checks during development.

See the SDK docs for setup and usage.

6) Deploy Your dApp

Deploy on XRPL EVM Sidechain (testnet/mainnet as applicable).
Use the correct BridgedBiomapper contract address for XRPL EVM.
Ensure your frontend links to the Biomapper App for onboarding.

Resources

Biomapper App: https://biomapper.hmnd.app
Docs: https://link.humanode.io/docs/biomapper
SDK: https://link.humanode.io/docs/biomapper-sdk
XRPL EVM Integration Guide: https://link.humanode.io/docs/biomapper/integration/chains/xrpl
XRPL EVM Sidechain: https://www.xrplevm.org/

By integrating Biomapper with your XRPL EVM dApp, you add Sybil resistance, keep rewards and governance human, and maintain privacy with minimal changes to your codebase. If you need help, join the Humanode Discord or check the docs.