For wallet developers, the goal is simple: ship a great product, fast. But building a secure, self-custodial wallet is anything but simple. Engineering the core account, abstracting gas, and integrating complex in-demand features like swaps or lending protocols can delay a product launch by months.
This is the exact development challenge Tether set out to solve with its Wallet Development Kit (WDK).
The WDK is designed to be the fastest way for companies to launch full-featured, self-custodial wallets with world-class UX and native gas payments in Tether tokens right out of the box. It provides the core components needed to not only secure user assets but also to offer sophisticated DeFi capabilities from day one.
WDK’s ability to offer this combination of speed and power hinges on the engineering craft running behind the scenes. To build a truly open solution, Tether needed deep expertise in the emerging standards for Ethereum account abstraction. That’s when Candide entered the picture.
The Build
From the first conversation, it was clear both teams shared a philosophy. This couldn’t be a quick build. It had to be foundational infrastructure built the right way.
The Foundation: Building on Safe Smart Accounts
Before solving for gas or transactions, Tether had to choose the core account architecture. The decision was immediate: build on Safe. As the most battle-tested smart account standard in the ecosystem, securing billions in assets, it was the only choice for an initiative focused on security and user trust. Candide’s role was to help Tether integrate Safe in a standard way, ensuring the WDK’s foundation was not just powerful, but interoperable and aligned with best practices.
The Transaction Bottleneck
How do you create an open, censorship-resistant front door for transactions? Many services rely on private relayers, creating a centralized point of failure. That had to be avoided.
The solution is a permissionless p2p network of Bundlers. node operators capable of processing Ethereum’s new account model. Candide, in collaboration with the Ethereum Foundation account abstraction team and Etherspot, has invested in this network for over three years. This ensures any developer or user can submit a transaction to the network without censorship, upholding the open principles of Ethereum.
The Gas Payment Puzzle
Next came the core problem: how do you programmatically transfer a user’s USDT or XAUt (Tether Gold) without requiring native gas tokens?
This is where Candide’s paymaster became the engine for the WDK’s gas feature. The paymaster is a set of smart contracts and offchain services that handle this logic. When a user requests to have their transaction paid in USDT or XAUt, the paymaster processes it by verifying the user’s USDT balance and paying the required gas in ETH. All while following a standard that ensures users can make the same request to any other paymaster service. It makes the entire complex process invisible to both the end-user and the developer using the WDK.
The Walled Garden Risk
Finally, both teams needed to ensure they weren’t building a powerful but closed-off system. By adhering strictly to official account abstraction standards and ERC-4337, Tether ensured the WDK remains interoperable and future-proof. Developers using the kit aren’t locked into Candide. They can use any standard-compliant bundler or paymaster. It was a crucial decision to contribute to a healthier, more composable ecosystem.
What This Unlocks Today
With the launch of Tether’s WDK, powered by Candide’s smart account infrastructure, developers can now build wallets that offer:
- Transaction fees paid seamlessly in USDT or XAUt
- Battle-tested Safe smart accounts right out of the box
- An open-source, standards-based foundation with no proprietary lock-in
The tools are ready. Now it’s time to build.
Explore the Tether WDK on their Wallet Docs | Get started today using Candide Bundler and Paymaster infrastructure in our Developer Dashboard