Overview
This tutorial provides a step-by-step guide to building a simple loan management system using Blnk Finance. You’ll learn how to:- Disburse loans to customers.
- Calculate and apply interest.
- Process repayments.
- Monitor loan status effectively.
Designing your map
Before writing code, it’s crucial to design a money movement map that outlines how money moves in your system. This serves as the blueprint for your implementation. This map shows three key aspects our lending fund flow:-
The
Customer Loan Wallet
tracks the amount owed by the customer. All loans disbursed to the customer are debited from their loan wallet. A zero balance indicates that all debt has been fully repaid. -
The
@InterestRevenue
records all interest earned from loan customers.
Prerequisites
Before starting, ensure you have:- A running Blnk server instance (e.g. at
http://localhost:5001
). - An API key for Blnk (replace
YOUR_API_KEY
in the code examples). Required for authenticated requests. - The Blnk CLI installed or a connected Blnk Cloud workspace to view your ledger data.
Create your ledgers
First, we create 2 ledgers.Customer Accounts
to organize all customers’ main accounts.Loan Accounts
to organize all loan accounts.
Create customer balances
First, we create the customer’s balance:Disbursing a loan
When the loan is disbursed, money is deducted from theLoan Balance
to the Main Balance
.
Example scenario
Calculate and charge daily interest
Next, we need to calculate daily interest based on the formula , where:- P is the principal (loan amount or remaining balance)
- R is the daily interest rate
- T is time (1 day for daily interest)
Loan Balance
to the @InterestRevenue
.
Example scenario (cont'd)
Loan repayments
When a customer makes a loan repayment, the money moves from their main balance to the loan balance.Check loan status
We can check if a loan is fully repaid by verifying if the loan balance is zero or positive:Conclusion
You now have a fully functional loan management system built with Blnk Finance. This system can:- Create and manage loan accounts
- Disburse loans
- Calculate and charge daily interest
- Process loan repayments
- Track loan status
- Track due dates: Enhance the loan metadata to include payment schedules and due dates to monitor late payments.
- Audit trail: Use detailed metadata for all transactions to maintain a comprehensive audit trail.
- Schedule interest charges: Set up a cron job or scheduled task to automatically calculate and charge interest daily.