The problem TaniFi solves

TaniFi: Bringing On-Chain Finance to the Offline Farmer 🌾⛓️

TaniFi is a decentralized, Sharia-compliant agricultural finance protocol built on Lisk Layer 2. It bridges the digital divide by allowing unbanked farmers to access global DeFi liquidity using simple USSD (2G) technology, without needing internet access or smartphones.

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🚩 The Problem It Solves

Agriculture contributes significantly to the economy of emerging markets, yet smallholder farmers remain trapped in poverty due to a structural "Agricultural Trilemma":

1. The Digital Divide (Accessibility):

• Reality: 40% of rural areas in Indonesia are internet "blank spots".
• Issue: Most modern DeFi and Fintech apps require 4G smartphones and data plans, excluding millions of farmers who only possess feature phones (Nokia-style devices).

2. Predatory Financing (Fairness):

• Reality: Formal banks reject farmers due to lack of land certificates (collateral).
• Issue: Farmers are forced to rely on "Tengkulak" (loan sharks) with interest rates as high as 20% per month, trapping them in a cycle of debt.

3. The Trust Deficit (Transparency):

• Reality: Previous centralized agritech platforms (e.g., the TaniFund & eFishery cases) suffered from internal fraud and data manipulation ("double bookkeeping").
• Issue: Global investors lost trust in funding agriculture because they cannot verify if the money actually reached the farmer or was used for planting.

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💡 What Can People Use It For?

TaniFi serves three distinct user groups within the ecosystem:

1. For Unbanked Farmers (The Borrowers)

• Access Capital Offline: Dial a simple short code (e.g., *777#) to request funding for fertilizer or seeds without needing a bank account or internet.
• Build Digital Reputation: Every repayment creates an on-chain credit score (Soulbound Token), allowing them to access larger capital in the future based on performance, not assets.
• Fair Profit Sharing: Instead of paying fixed interest (Riba), farmers share a percentage of their harvest profit. If the harvest fails due to floods (verified by weather data), they are not crushed by debt.

2. For Global Investors (The Lenders)

• Fund Real-World Assets (RWA): Directly fund specific agricultural cycles (e.g., "Banyumas Coconut Sugar Export Batch #42") using stablecoins (USDC/IDRX).
• Track Impact: View transparent, real-time data on how funds are disbursed and utilized via the blockchain ledger.

3. For Cooperatives (The Off-Takers)

• Supply Chain Financing: Get instant liquidity to pay farmers immediately upon harvest collection, rather than waiting 30-60 days for export payments.
• Digital Administration: replace manual logbooks with an immutable digital ledger that tracks every kilogram of harvest from farm to table.

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🛡️ How It Makes Tasks Easier & Safer

TaniFi innovates by combining Low-Tech interfaces with High-Tech security.

Making Financing Easier (UX Innovation)

• No Internet Required: Uses USSD (GSM protocol), accessible on 99% of mobile phones globally.
• Gasless Transactions: Farmers don't need to buy ETH or LSK to pay for gas fees. TaniFi uses Account Abstraction (ERC-4337) Paymasters to sponsor transaction costs, creating a seamless experience.
• Instant Disbursement: Funds are sent as digital vouchers to local partner stores, ensuring farmers get what they need (fertilizer/seeds) instantly without waiting for bank approvals.

Making Investing Safer (Security Innovation)

• Triple-Entry Accounting: Unlike centralized servers that can be manipulated, every transaction is recorded on the Lisk Layer 2 Blockchain. This creates a "Single Source of Truth" that cannot be altered by the platform owners.
• Smart Contract Enforcement: The "Musyarakah Vault" automatically splits harvest revenue between the investor and farmer according to the pre-agreed ratio. No one can run away with the profits.
• Automated Risk Mitigation: Integration with Chainlink Functions allows the smart contract to read weather data (BMKG). If a flood occurs, the contract can automatically trigger insurance protocols or restructure the loan, removing human bias and fraud.

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Challenges I ran into

Challenges I Ran Into

Building TaniFi within a hackathon timeline was far from smooth. Below are the real technical hurdles I faced during development, and how I solved them.

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1. Environment & Tooling Setup (WSL + Docker + Foundry)

The Challenge

At the very beginning, the development environment itself became a blocker:

• Docker was installed but the daemon could not start
• WSL was outdated and incompatible with Docker Desktop
• Ubuntu installation via Microsoft Store repeatedly failed
• Disk space constraints on the system drive caused additional friction

These issues prevented even basic services (PostgreSQL, Redis, NestJS) from running.

How I Solved It

• Updated WSL manually using wsl --update --web-download
• Migrated development fully into WSL2 (Ubuntu) instead of mixing Windows + Linux tooling
• Reconfigured Docker Desktop to use WSL backend
• Carefully chose a non-destructive storage strategy (avoiding data loss on external SSDs)

Lesson learned:
A “broken” environment can look like a code problem. Fixing infra early saved massive time later.

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2. Prisma ORM Breaking Changes (Prisma v7)

The Challenge

Prisma introduced breaking changes in version 7:

• datasource.url is no longer allowed in schema.prisma
• Connection configuration moved to prisma.config.ts
• PrismaClient must now be constructed with explicit options

This caused multiple runtime and compile-time errors such as:

• P1012: datasource property 'url' is no longer supported
• PrismaClientInitializationError

How I Solved It

• Carefully read updated Prisma documentation
• Migrated DB config to prisma.config.ts
• Refactored PrismaService to properly extend PrismaClient
• Regenerated Prisma Client and re-ran migrations

Lesson learned:
Using “latest” tech gives advantages, but only if you are ready to adapt to breaking changes.

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3. USSD State Management & Stateless HTTP

The Challenge

USSD flows are stateful, but HTTP requests are stateless.

Problems encountered:

• Session resets on every request
• User inputs like 2*5000000 not parsed correctly
• Back / Exit logic (0, 00) behaving inconsistently
• Edge cases causing unexpected session termination

How I Solved It

• Introduced Redis as a session store with TTL
• Implemented an explicit finite state machine:
  • START
  • AWAIT_AMOUNT
• Normalized USSD input parsing using text.split('*')
• Carefully handled Back and Exit flows per state

Lesson learned:
USSD is deceptively simple. Treat it like a protocol, not just input text.

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4. Audit Logging vs Database Schema Drift

The Challenge

While adding audit logging (UssdAudit), the backend crashed with:

The table `public.UssdAudit` does not exist

The Prisma client expected the model, but the database schema had not been migrated.

How I Solved It

• Verified Prisma schema vs actual database tables
• Added the missing model
• Ran prisma migrate dev to sync schema
• Confirmed audit rows were being written correctly

Lesson learned:
Schema drift is silent but deadly. Migrations are not optional.

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5. Lisk Sepolia Gas & Token Confusion

The Challenge

After receiving funds from faucet:

• Blockscout showed 0.1 LSK
• MetaMask showed balance
• Foundry (cast balance) returned 0

This caused deployment failures with:

insufficient funds for gas * price + value

How I Solved It

• Learned that Lisk Sepolia gas is paid in ETH, not LSK
• Realized I had received tokens, but no gas currency
• Adjusted funding strategy accordingly
• Confirmed gas requirements via RPC and Foundry output

Lesson learned:
Not all L2s use the same native gas semantics. Always verify what pays gas.

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6. Smart Contract Verification on Blockscout

The Challenge

Contract deployment succeeded, but verification repeatedly failed with:

• Fail - Unable to verify
• missing field sources
• Partial mismatches between compiler metadata

How I Solved It

• Confirmed on-chain bytecode using cast code
• Identified that Blockscout requires Standard JSON Input
• Used Foundry’s --show-standard-json-input
• Uploaded the correct JSON via Blockscout’s UI
• Successfully achieved Verified (Partial Match) status

Lesson learned:
Verification is not automatic. Tooling literacy matters as much as Solidity.

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Final Reflection

Most challenges in this project were not about writing code, but about:

• Tooling maturity
• Protocol understanding
• Infrastructure debugging
• Reading documentation carefully under time pressure

Overcoming these issues significantly strengthened both the technical robustness of TaniFi and my confidence as a builder.