Expendi is a financial management tool designed to bring clarity, control, and automation to digital asset under a single self-custody platform.

• Spend Easily: Expendi supports spending USDC from organized expense buckets to local merchants’ mobile wallets in Kenya, Uganda, Ethiopia, and Ghana. Spending is gasless, powered by Account Abstraction using Pimlico as our bundler. This structure helps users clearly understand where their money is going, making everyday crypto spending transparent, organized, and effortless.

• **Smart Budgeting: ** Users can set spending limits enforced by smart contracts, helping them stay disciplined and avoid overspending.

• Targeted Savings: Create personalized savings goals and earn DeFi yield automatically through Morpho Vaults, turning every goal into a growth opportunity.

• Auto Deposits: Expendi automates regular contributions toward savings goals, making it easier to stay consistent and reach targets faster.

• **Earn While You Save: ** User can deploy funds into yield strategies, ensuring no idle crypto sits unproductive.

• Self-Custody: All actions are on-chain, ensuring users have full control of their assets, secure and decentralized.

Three significant technical hurdles we overcame while building Expendi:

Morpho Vault Share Balance Accounting

The Challenge:

Morpho Protocol's ERC-4626 vaults issue "shares" that appreciate over time. We needed to track original principal, vault shares, and current value simultaneously. Miscalculating during withdrawals could cause users to lose interest earnings or receive incorrect reward tokens.

The Solution:
Implemented dual-tracking of

currentAmount

shareBalance

The Goal Deletion

The Challenge:

Users could delete savings goals with funds still deposited, permanently trapping assets. With Gelato automation enabled, we also needed to cancel recurring deposit tasks and ensure our subgraph properly handled deletions to prevent "ghost" goals in the UI.

The Solution:

Multi-layer protection: smart contract validation requiring zero balances, automatic Gelato task cancellation, subgraph entity removal, and frontend warnings guiding users through the proper deletion sequence. Ensures fund safety even with direct contract interactions.

Gelato Automation Time Unit Conversion

The Challenge:

Solidity uses seconds for time constants, but Gelato expects milliseconds. Our initial implementation passed Solidity time values directly, causing a 10-minute check interval to trigger every 10 milliseconds - potentially draining user accounts through excessive automated deposits.

The Solution:

Multiplied all time intervals by 1000 for millisecond conversion. Bug was invisible in local testing and only appeared during Base Sepolia testnet integration. Taught us to verify unit conversions and always perform real network integration tests.

https://github.com/DennohKim/Expendi

https://www.expendi.app/

Expendi stands out as the first programmable budgeting app built for crypto users, integrating smart contract automation and DeFi yield generation into everyday money management. Unlike traditional tools that only track spending, Expendi enforces financial discipline at the protocol level—when your set limits are reached, the blockchain itself prevents further transactions. This creates unbreakable spending control without relying on human willpower.

Beyond budgeting, Expendi turns idle funds into earning opportunities by deploying them into DeFi vaults like Morpho, and allows gasless transactions using Account Abstraction (via Pimlico), making it accessible even for non-technical users. The beta build validates this vision: we’ve processed over $2,000 across 600 transactions with 60 active testers, demonstrating early user interest and functional reliability.

The app already supports spending USDC through organized expense buckets to local merchants’ mobile wallets in Kenya, Uganda, Ethiopia, and Ghana—proving real-world crypto usability.

Our ideal users are crypto natives, freelancers, and Web3 builders who actively hold and spend stablecoins like USDC for daily transactions. These users value self-custody, transparency, and practical financial tools that make it easier to budget, save, and spend in crypto—especially across regions like Kenya, Uganda, Ghana, and Ethiopia, where mobile money adoption is high.

We confirmed this audience fit through user testing and on-chain activity from our alpha release. Over 60 testers participated, providing feedback that helped refine key features such as targeted savings, expense buckets, and gasless transactions. Additionally, our bundler data shows close to 1,000 user operations executed through Pimlico, validating consistent real-world usage and engagement.

The results clearly show that Expendi resonates with crypto users seeking practical, disciplined, and seamless ways to manage their on-chain finances—bridging DeFi yield with everyday financial control.

Expendi operates at the intersection of crypto budgeting, saving, and spending, so our competitors range from traditional budgeting apps to emerging Web3 financial tools.

Main Competitors

1. YNAB (You Need A Budget) – https://www.ynab.com

A leading budgeting app focused on discipline and goal tracking, but supports only traditional finance—no crypto or DeFi integration.

2. Lunch Money – https://lunchmoney.app

Offers modern multi-currency budgeting with limited crypto tracking, but lacks smart contract automation or savings yield integration.

3. CoinStats – https://coinstats.app

A strong crypto tracker and DeFi dashboard, but does not help users plan or enforce spending habits.

4. Spenda – https://spenda.africa

Focused on helping users in Africa spend crypto via virtual cards and bill payments, but lacks budgeting and savings automation.

5. InCrypto – https://incrypto.finance

A wallet offering stablecoin accounts and savings features, but without enforced budgeting or automated DeFi yield.

6. Pretium Africa – https://pretium.africa/

Stablecoin wallet for everyday crypto usage.

How Expendi is Different

Expendi is the first self-custody budgeting app built natively for Web3, combining smart contract automation, DeFi yield, and real-world crypto spending in one experience.

• Smart Contract-Enforced Budgeting: Budgets are automatically enforced on-chain, eliminating overspending through immutable rules.

• Targeted Savings with Yield: Users earn yield on their savings goals through Morpho Vaults, turning savings into passive income.

• Gasless Transactions: With Account Abstraction (via Pimlico), users can interact seamlessly without paying gas fees—ideal for onboarding new users.

• Organized Spending Buckets: Users can clearly see where their crypto goes and spend directly from categorized buckets.

• Real-World Utility: Enables USDC spending to merchants’ mobile wallets across Kenya, Uganda, Ethiopia, and Ghana, bridging DeFi with everyday life.

Expendi is a complete financial layer for crypto and non crypto native users that combines discipline, automation, and real-world utility, making crypto truly practical for daily financial management.