Tether, the biggest player in the digital asset market, has taken another step toward building the next generation of financial tools. The company has integrated Lightspark’s Spark Bitcoin Lightning infrastructure into its open-source Wallet Development Kit (WDK), giving developers a single solution for fast Bitcoin and stablecoin payments.
The WDK is built as a modular toolkit that lets developers and businesses add non-custodial wallets into apps, websites, and devices. It supports USD₮, XAU₮, Bitcoin, and other tokens.
With Spark now part of the system, wallets can handle Bitcoin base layer transactions, Lightning, and Spark payments without the usual trade-offs between speed, cost, and security.

The company plans to make the WDK fully open-source, allowing the wider developer community to contribute and improve the technology.
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By using Spark’s Lightning infrastructure, developers can add instant Bitcoin and stablecoin transfers to mobile, desktop, and even embedded devices. The transactions happen without needing custodial services or centralized cloud systems.
Lightspark’s platform offers the tools needed for modern payment flows and smooth integration into existing business systems. This supports Tether’s goal of a financial network built on privacy, decentralization, and permissionless access.
Paolo Ardoino, Tether’s CEO, sees the integration as a turning point. He said:
This advancement will empower innovators to develop programmable and resilient monetary systems that serve individuals, machines, and diverse communities alike. Our mission is to make Bitcoin Lightning accessible to everyone, facilitating instant global transactions while protecting custody and privacy.
The WDK is designed to adapt to an era shaped by artificial intelligence, automation, and distributed ownership. Its flexibility makes it a strong foundation for developers building tomorrow’s decentralized applications.
This integration also sets up the WDK for use in Tether’s QVAC ecosystem, a decentralized AI agent platform. In this setup, autonomous agents will be able to transact in USD₮ and Bitcoin, completing secure, large-scale operations without human oversight.
David Marcus, Lightspark’s CEO, highlighted Tether’s strong alignment with Bitcoin in the stablecoin sector. He expects WDK to capture a significant share of the consumer payments market thanks to Spark’s speed and cost efficiency.
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