Loading...
Supporting developers, startups, and full-fledged companies building on Stellar and Soroban
© 2025 Stellar Development Foundation
Subscribe to the Newsletter
By Microvault by Shamba Records
Feature: Microvault is a decentralized lending engine built on Stellar, designed to manage tokenized vaults through the SEP-56 standard. The platform offers a dual-layer approach: firms can deploy a turnkey, pre-built vault or configure custom smart contracts directly on the engine. Beyond core lending, the engine integrates Stellar Classic operations — including account sponsorship and delegated signing — with essential 'real-world' infrastructure like SMS/USSD mobile access, off-chain transaction logging, and integrated payment gateways for seamless off-ramping.
Stellar Implementation: This entire system is built on Soroban, Stellar's smart contract platform. It uses SEP-56 vault standard smart contracts to manage the liquidity pools and lending operations transparently on-chain. To enhance security, the engine plans to use OpenZeppelin's audited SEP-56 implementation on Soroban to protect against common exploits like inflation attacks.
Feature: To eliminate friction for users who are not Web3-savvy, Microvault manages wallets on their behalf. Borrowers interact with the system using their mobile phone number, which is tied to a dedicated Stellar child account created for them.
Stellar Implementation: The engine uses Hierarchical Deterministic (HD) wallets (implementing BIP-32, 39, and 44) to create a master treasury account that can generate multiple unique child accounts on the Stellar blockchain. Each user is assigned a child account, allowing for clear auditing of transactions while the engine handles the complexity of key management.
Feature: End-users do not have to worry about paying network transaction fees (gas) to receive their loans.
Stellar Implementation: All transactions originating from a user's child account are signed and sponsored by the central treasury wallet (the master account). This leverages a native feature of the Stellar network, ensuring a seamless experience for the borrower.
Feature: The engine is designed for accessibility, allowing users to request loans and receive notifications via simple USSD menus and SMS messages, which is critical in regions with limited internet access. To ensure high reliability, we have implemented Robust Error Handling for USSD/SMS Flows. We fully understand the criticality of flawless USSD/SMS operations; therefore, our system employs idempotent request handling, meaning every transaction request has a unique identifier tracked end-to-end. This prevents duplicate transactions in the event of network timeouts or double-submissions.
Errors are instantly logged and trigger automated alerts to our engineering team. Crucially, users receive context-aware messages that explain issues clearly with explicit instructions to retry or seek help—avoiding confusing technical codes that could alienate non-technical users. Continuous monitoring and fallback mechanisms, such as SMS confirmations and dedicated user helplines, are embedded to ensure minimal disruption and maintain user trust even during localized network instability.
Stellar Implementation: While the user interacts via USSD, the backend server translates these requests into on-chain actions. The server uses JSON-RPC communication to call functions on Soroban and polls the Horizon API (Stellar's main API) to monitor the status of transactions like USDC withdrawals. By mapping the unique USSD session ID to a Stellar transaction hash, the system ensures that even if a mobile connection drops, the state of the loan request remains verifiable and consistent across both the off-chain and on-chain environments.
Feature: The platform allows loans to be managed on-chain in a stablecoin (USDC) but disbursed to users in their local fiat currency (e.g., Kenyan Shillings) directly to their mobile money wallets.
Stellar Implementation: Microvault integrates with Stellar-based on/off-ramp providers such as YellowCard and MoneyGram integration if approved by the SDF team. The engine orchestrates the withdrawal of USDC from the treasury account on behalf of user's child account on Stellar and sends it to the ramp provider, which then completes the final mobile money deposit.
6. AI-powered Credit Scoring Integration (Shamba Records)
Feature: To ensure undercollateralized loans are issued responsibly, Microvault integrates directly with Shamba Records’ agrarian data platform. The platform houses the AI-powered credit scoring engine which operates through a sophisticated, transparent, two-step process that accounts for real-world farming dynamics:
Dynamic Scoring: The data platform aggregates farmer data including economic indicators, seasonal production metrics, historic transaction records, and real-time market/weather data, to produce a granular and highly accurate credit score.
Limit Determination: This score informs individualized credit limits, balancing investment risk for lenders with the farmer's realistic capacity to repay based on their specific crop cycles and historical yield.
Stellar Implementation: The credit score and approved limit act as the "on-chain trigger" for the Soroban smart contracts. When a farmer requests a loan via USSD, the backend verifies their current standing against Shamba Records' agrarian data platform API. If the data platform approves, the backend invokes the borrow function on the SEP-56 Vault contract. This ensures that loan disbursements are not only seamless but are programmatically restricted to the pre-approved limits stored or validated by the smart contract logic, maintaining a decentralized and tamper-proof record of credit eligibility.
$80.0K
Shamba Records has already validated strong traction with 50,000+ active farmers across East Africa, backed by a formal MoU with Kenya’s Ministry of Agriculture to digitize 6.5M farmers and partnerships with cooperatives, MFIs, and CGIAR research bodies. We have conducted 300+ farmer and cooperative interviews confirming that lack of verifiable records is the primary barrier to credit, and our design directly reflects this demand. Shamba Records has also signed agreements with infrastructure partners for Microvault including Africa's Talking—USSD/SMS provider and YellowCard—on-ramp/off-ramp provider.
Microvault builds on this live ecosystem, with pilot on-chain deployments on Stellar’s Soroban platform (SEP-56 Vaults) and active integration discussions with lenders. With a roadmap to disburse $100M+ in loans within 3 years and scale to $200M for 5M farmers by 2030, the project is already validated both in market demand and technical feasibility, positioning it as a scalable solution to Africa’s $170B agricultural lending gap.
Deliverable: Complete End-to-End Functional MVP
Brief Description: This milestone focuses on the core technical foundation required to facilitate USSD-based lending. It includes the finalized system architecture and the development of the primary Soroban smart contracts (SEP-56 Vault standard) for liquidity pool management. Simultaneously, the backend engine will be built to bridge the USSD gateway with the Stellar network, ensuring that basic mobile requests can trigger on-chain logic. This results in a functional "alpha" prototype capable of processing a loan request from a mobile interface through to the smart contract layer.
How to Measure Completion: *
Public GitHub repository containing the finalized architecture diagrams, backend engine source code, and the Rust-based Soroban smart contract code.
A recorded video demonstration showing pool deposit and withdraw through Stellar Wallets Kit transaction signing, a user interacting with a live USSD menu to request a loan, which then triggers a successful event or transaction in the test or sandox environments.
Budget: $16,000 (20% of Award)
Engineering: $10,000 (Lead Developer and Rust/Soroban Engineer)
Infrastructure & Gateway: $4,000 (Cloud hosting setup and USSD service integration/telco provisioning)
Technical Documentation: $2,000 (Architecture mapping and API specifications)
Brief Description: This milestone moves the project into a realistic testing environment by integrating a fiat off-ramp provider on the Stellar Testnet. This allows the system to demonstrate the full "Circular Flow": USSD request -> Smart Contract Vault withdrawal -> Fiat Off-ramp execution (Money Gram) -> SMS confirmation. A structured pilot with a small group of test users will be conducted to identify edge cases, latency issues, and UI/UX friction points within the USSD flow.
How to Measure Completion:
Verified contract addresses for the SEP-56 vault deployed on the Stellar Testnet.
Verified integration of MoneyGram in sandbox environment as the off-ramp provider.
Successful transaction hashes showing a completed testnet vault fund disbursement from borrow event and MoneyGram off-ramp transaction triggered by the backend engine.
A Testnet Pilot Summary Report detailing transaction success rates, system latency metrics, and a log of bug fixes/optimizations implemented based on initial user feedback.
Budget: $24,000 (30% of Award)
Integration Engineering: $12,000 (Fiat off-ramp API integration — (MoneyGram & YellowCard) and backend-to-chain synchronization)
QA & Testing: $8,000 (Security hardening of the backend and rigorous unit/integration testing)
Pilot Operations: $4,000 (Managing the test user group and feedback synthesis)
Brief Description: This final milestone involves the deployment of audited SEP-56 smart contracts to the Stellar Soroban Mainnet and the official launch of the lending service. Central to this launch is the production-grade integration of the Shamba Records agrarian data platform, which feeds real-time farming metrics into it's credit engine. To ensure adoption among low-digital-literacy farmers, this phase includes comprehensive onboarding support: face-to-face training via extension officers, offline video tutorials, and a dedicated assistance helpline. A public-facing monitoring dashboard will also be launched to display anonymized system health and vault transparency for all stakeholders.
How to Measure Completion:
Verified Mainnet contract addresses for the SEP-56 vault on the Stellar Expert explorer.
A live, public-facing URL for the System Health Dashboard displaying real-time vault status, engine uptime, and anonymized disbursement metrics.
Formal confirmation (press release or public announcement) documenting the successful integration of the Shamba Records agrarian data platform and the processing of the first live mainnet disbursement to a verified farmer.
An onboarding summary report confirming the completion of the first field training session and the deployment of offline support materials.
Budget: $32,000 (40% of Award)
Mainnet Deployment & Ops: $14,000 (Contract activation, network fees, and security hardening).
Transparency Dashboard: $8,000 (Front-end development for the public metrics portal).
Agrarian Integration & Farmer Support: $10,000 (Engineering support for Shamba Records data syncing and field onboarding/extension officer training).
Our team combines expertise in agriculture, technology, and finance, with a shared mission to empower smallholder farmers through innovation. We bring together professionals experienced in AI, blockchain, and digital platforms, alongside agronomists and field experts who deeply understand farmer needs. With proven backgrounds in scaling tech solutions and driving impact in emerging markets, the team is well-positioned to deliver sustainable growth. Collectively, we blend technical excellence, on-the-ground experience, and strategic partnerships to ensure Shamba Records not only scales effectively but also creates lasting value for farmers and communities**.**
Kevin Kihara Maina
George Maina
Peter wesly
mugane
By Microvault by Shamba Records
MicroVault - Microlending on Stellar