Crypto Module for eWallets by Qulix

Seamlessly extend your electronic wallet with a feature-rich crypto layer. The Crypto Module by Qulix is a standalone, easy-to-configure and well-documented solution that connects your existing eWallet to public blockchains.

Key Principles of the Solution

solution

The module is built and delivered according to several core principles:

Open code and documentation The client receives access to source code and comprehensive documentation, which simplifies onboarding, audit, and further development.
Dedicated team for MVP and beyond Qulix assigns a dedicated team to launch the MVP and support subsequent product evolution.
Plug & Play connection via API The module is designed to integrate quickly with existing financial systems using well-structured APIs and standard integration patterns.
Support with licensing questions Qulix can act as a technology partner and assist in resolving licensing issues related to the technical side of the solution.
Flexible cooperation models You can: use the crypto module as a PaaS solution, run it as a white-label product, or acquire full ownership of the solution.

About the Crypto Module

about

The Crypto Module is a standalone component that extends the functionality of your electronic wallet with cryptocurrency features:

It connects an existing eWallet solution to blockchains.
It offers multiple integration interfaces for quick and effortless setup.
It is suitable for: MSB/EMI companies, and product companies that provide fiat wallet solutions.

This makes it a practical choice for organizations that already work with fiat wallets and want to add a crypto layer while keeping their current architecture and client interfaces.

Capabilities

features

Crypto Wallets Management The module supports a structured approach to managing different types of crypto accounts:

Treasury, operational, and end-user crypto accounts
Virtual accounts
KYC/KYB flows for account activation
Aggregated accounts (the same asset across multiple blockchains)
Supported networks include Ethereum, Binance Smart Chain, and Tron, with Solana and Base planned

This functionality allows you to handle balances across various entities, jurisdictions, and networks, while keeping a unified operational model.

Crypto Transactions The Crypto Module provides tools for processing and controlling transactions, including:

Top-up and withdrawal operations
Cross-chain transfers between wallets
Exchange operations: crypto-to-crypto and fiat-to-crypto
Integration with multiple crypto gateways
A built-in OTC desk for larger or specific trades

All operations are exposed through the module’s interfaces and can be orchestrated from your existing platforms and back-office systems.

Crypto Liquidity and Treasury Management The module also supports liquidity and treasury functions, such as:

Detailed views of crypto balances across jurisdictions and entities
Liquidity rebalancing between nodes or legal entities
Integration with liquidity providers for on-ramp and off-ramp operations (e.g. Zodia, Velocity, Kraken, etc.)
FX forecasting and exchange-rate management tools

These capabilities help your treasury team manage coverage, pricing, and liquidity allocation in a structured, transparent way.

Crypto Cards (Beta) For use cases that require card functionality, the Crypto Module includes card-related features in beta:

Issuance of virtual crypto cards
Integration with Apple Pay
Direct connections to multiple card processors and acquirers

This card functionality is designed as an extension of the core module and can be introduced step-by-step, in line with your roadmap and regulatory context.

Channels for Users and Operators To ensure accessibility for different user groups, the platform is available through:

Web and mobile applications for end-users and operators
Admin and Operator Portals with role-based access control to safeguard system security

You can use these ready-made interfaces or build your own front ends on top of the module’s APIs.

API and Integration Options

options

The Crypto Module includes a well-documented API for smooth integration into existing financial systems. There are two primary integration models:

API-level integration

Your team is responsible for developing and maintaining the front end. Qulix provides the crypto module, APIs, and documentation, and can support front-end implementation if needed.

Front-level integration

Qulix provides a ready-made front end. It can be embedded into your ecosystem either as: a micro-frontend, or a standalone application.

For complex environments and multi-system architectures, Qulix recommends a dedicated technical meeting to define integration scenarios and select the optimal approach.

Architecture Overview

architecture

The Crypto Module is implemented as a separate solution that interacts both with your systems and with external providers

Key elements of the architecture include:

External integrations

Currency rate providers (e.g. Twelve Data, etc.)
Ethereum blockchain (via EtherScan)
BNB Chain (via BscScan)
Tron blockchain (via TronScan)

Crypto Module Solution

UI layer
Business logic layer
Blockchain Integration Module

Integration interfaces

REST API
gRPC API
Kafka
HTTP callback hooks
WebSocket

Security and storage

Secure key storage
Database storage
Encrypted channels (HTTPS, JDBC, SSL)

This architecture enables the module to be embedded into a wide range of financial solutions while keeping clear separation of responsibilities between your core systems and the crypto layer.

Tech Stack

tech stack

The technology stack of the Crypto Module is aligned with modern fintech and production requirements for scalability, observability, and security:

Backend and data

Spring Framework
Hibernate
PostgreSQL
OpenAPI (Swagger)

Blockchain and smart contracts

Ethereum blockchain
Web3j
Solidity
Smart contracts, including ERC-20
OpenZeppelin
Hardhat

Tooling and DevOps

Node.js
Yarn
GitLab CI/CD
Docker
Kubernetes
Terraform

Cloud infrastructure (AWS)

EC2
RDS
S3
CloudWatch
VPC
SES
SNS
Route 53
IAM

Why Qulix?

why us

Qulix is a long-term technology partner with a strong focus on fintech and digital solutions:

Selected for The Global Outsourcing 100 list by IAOP (2020, 2022, 2023, 2024)

Full-cycle development experience across domains from eCommerce to adtech

Around 80% of projects are fintech solutions

25+

years in the market

200+

clients from more than 30 countries

500+

qualified in-house engineers

This background allows Qulix to deliver not only the crypto module itself, but also the surrounding integration, customization, and long-term support.

Contacts

get in touch

We’d love to hear from you!

Tell us about your project or the challenge you have, and we’ll get back to you soon.

Prefer direct contact?

E-mail us at request@qulix.com