Visit website

Join Community

Blnk Finance

Blnk Ledger

Blnk CLI

API Reference

What's new?

Update Balance Monitor

Condition

UpdateBalanceMonitorRequest

The open-source backend for building fintech products at scale.

Discover Blnk, the open-source backend for building fintech. Accurately record transactions and scale your fintech product reliably with Blnk.

Open-source Financial Ledger for Developers - Blnk

Start here

Welcome to Blnk

Learn all about the different statuses of a transaction.

Learn about the different statuses in your Blnk Ledger

Transaction statuses - Blnk

Statuses

Transaction statuses

Learn how to ensure correctness when recording amounts with floating points in your Blnk Ledger

Transaction precision - Blnk

Precision

Transaction precision

Learn how to represent overdrafts and negative balances in your ledger.

Applying overdrafts - Blnk

Overdrafts

Applying overdrafts

Use inflight to set rules for transactions to meet before they get applied to your ledger.

Learn how to manage inflight transactions with Blnk’s open-source ledger. Understand the process of holding and committing transactions based on specific conditions.

Inflight transactions - Blnk

Inflight

Applying inflight

Learn how to initiate a refund in your Blnk Ledger

Refunding transactions

Refunds

Record transactions between different currencies.

Record transactions between different currencies in your Blnk Ledger.

Applying rates - Blnk

Rates

Applying rates

Learn how to schedule a transaction for a later date in your Blnk Ledger.

Scheduling transactions - Blnk

Scheduling transactions

Learn how to send money from multiple sources to a single destination.

Multiple sources - Blnk

Multiple sources

Learn how to send money from a single source to a multiple destinations.

Learn how to send money from a single source to a multiple destinations with the Blnk Ledger.

Multiple destinations - Blnk

Multiple destinations

Learn how Blnk uses transaction hashing for immutability.

How Blnk uses SHA-256 hashing to ensure transaction integrity. Understand hashing, verify transactions, and explore the security benefits it provides.

Transaction hashing - Blnk

Transaction hashing

Creating a money movement map for your fintech application.

Learn how to model and visualize the flow of funds within your fintech application.

Money movement maps - Blnk

Money movement map

Money Movement Maps

Arrange your ledgers and ledger balances for easy navigation and scale.

Learn how to design scalable ledger architecture with Blnk’s open-source ledger. Discover best practices for setting up ledgers and managing transactions in your fintech applications.

Designing your ledger architecture - Blnk

Ledger architecture

Architecting your ledger

Learn how to use the General Ledger to organize the flow of funds in your system.

Learn how to use a General Ledger to keep track of revenues, fees, charges, assets, and liabilities within your fintech application.

Working with a General Ledger - Blnk

General ledger

General Ledger

Learn how to set your asset classes (currencies).

Learn how to represent currencies, crypto, and custom classes, and understand how precision prevents errors due to floating-point approximations.

Defining asset classes - Blnk

Asset classes

Defining asset classes

Learn how to create and manage internal balances.

Learn how to manage internal balances with Blnk’s open-source ledger. Understand the process of creating and using internal balances for efficient transaction tracking in your application.

Managing internal balances - Blnk

Internal balances

Monitor balances and get notified via `webhook` when they meet set conditions.

Balance monitoring - Blnk

Balance monitoring

Correct errors, reconcile transactions, and ensure accurate financial records in your application.

Learn how to adjust ledger balances with Blnk’s open-source ledger. Correct errors, reconcile transactions, and ensure accurate financial records in your application.

Fixing reconciliation discrepancies (a step-by-step guide) - Blnk

Adjusting balances

Master ledger cleanup in Blnk! Learn to close and zero out balances with debits or credits, finalize them, and prevent future transactions.

Closing balances - Blnk

Closing balances

Get started

Get started with Reconciliations

Learn how to prepare your external data for upload.

External data

External Data Preparation

Learn how to set and manage matching rules for your reconciliation process.

Matching rules

Choose the strategy that best fits your financial workflows.

Reconciliation strategies

Learn how to create and associate identities with balances.

Identity management - Blnk

Guide

Introducing Identity

Getting started with Search - Blnk

Overview

Getting started with Search

Master Blnk Search queries! Use the q field and filter_by for precise results. Explore multiple terms, exclusions, and find what you need fast!

Querying parameters in Search - Blnk

Querying parameters

Learn how to use filters to streamline your search results.

Unlock the power of Blnk Search! Filter ledger data with matching, negation, filtering numbers & dates, and combining conditions. Find what you need, fast!

Filtering parameters in Search - Blnk

Filtering parameters

Learn how to use sorting to order your search results.

Order your search results by creation date, scheduled date, or combine for multi-step sorting.

Sorting parameters in Search - Blnk

Sorting parameters

Learn how to use pagination to manage large sets of search results.

Pagination parameters in Search - Blnk

Pagination parameters

Build multicurrency wallets with the Blnk Ledger.

Multicurrency wallets

Managing transfers with side effects in the Blnk Ledger

Managing transfers

Managing transfers with side effects

Implement virtual cards issuance with the Blnk Ledger.

Virtual cards

Virtual cards issuance

Build a loyalty points system with the Blnk Ledger.

Loyalty points system

Implement an expense management platform with the Blnk Ledger.

Expense management

Expense management platform

Build an escrow application with the Blnk Ledger

Escrow application

Build a savings application with the Blnk Ledger.

Savings application

Configure real-time alerts for transaction events and handle error notifications through Slack. Stay updated with critical information.

Notifications

Handling notifications

Learn how to configure your Blnk server with the blnk.json file.

Configuration file

Configuring your Blnk server

Update your configuration, ensure domain setup, and verify secure connections for a safer financial application.

Enable HTTPs

Enable HTTPs for Blnk server

Enable secure mode, manage secret keys, and follow best practices for a secure environment.

Secure Blnk

Secure your Blnk server

Learn to perform load testing on your Blnk server using k6.

Load testing

Learn how to backup your Blnk data to a local disk.

Back up your Blnk server’s PostgreSQL database. Follow this guide for setup, verification, best practices for storage, and restoration steps to ensure data safety.

Backup to Disk - Blnk

Backup to Disk

Learn how to backup your Blnk data to the cloud.

Backup your Blnk server to Amazon S3. Follow this guide for setup, configuration, automation, and best practices for secure cloud backups.

Backing Up Blnk Ledger to Amazon S3 - Secure Cloud Storage

Backup to S3

Backup to Amazon S3

An engineer's guide to the Double Entry principle with Blnk.

Learn the basics, explore scenarios, and simplify record-keeping. Ensure accurate tracking, prevent fraud, and build a robust system.

Double-entry principle in the Blnk Ledger

Double-entry principle

Understanding the double-entry principle

Learn how and why Blnk queues transactions.

Process transactions smoothly with Blnk! Learn how queuing and optimistic locking manage concurrency, prevent data conflicts, and ensure data integrity.

How the Blnk Ledger manages concurrency

Handling concurrency

View the list of all countries and their corresponding ISO currency code.

Currencies

List of countries and their currency code

Create ledger

Get Ledger

Create Balance

Get Balance

Record Transaction

Refund Transaction

Update Inflight Transaction

Create Balance Monitor

Get Balance Monitor

Back DB

Back DB To S3

Blnk v0.6.3 (Latest)

Blnk v0.6.1

Advanced control over transactions with multiple sources/destinations and inflight.

API Reference

Update Balance Monitor

Path Parameters

Body