Blnk

Judgement

What it is

Building block

What it does

A double-entry ledger service for fintech products, handling balances, transactions, inflight holds, reconciliation and multi-currency through an API.

Adopt it when

You are building wallets, payments or lending products and need a ledger rather than writing one.

Watch out

Pre-1.0, and the company steers users toward its paid cloud and support plans.

Ready for

Usable

Runs as

Self-hosted server and cloud service

Built with

Go, PostgreSQL and Redis

How established

Established: started 3 years ago, latest release v0.15.8.

What the license allows

You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-03 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: Blnk → Go → runs on a microchip

How compilers were built, back to punched paper tape

Open-source alternatives to Blnk

1. 1
   TigerBeetle tigerbeetle

   The financial transactions database designed for mission critical safety and performance.

   Building block Usable You are building a payments or ledger system that needs very high throughput and correctness.

   ★ 17k Apache-2.0 Zig Active, pushed 3 days ago
2. 2
   Fineract apache

   Apache Fineract

   Complete system Production-ready You run or build a lending, microfinance or savings business and need an open core banking back end.

   ★ 2.6k Apache-2.0 Java Active, pushed today
3. 3
   Django Ledger arrobalytics

   Django Ledger is a double entry accounting system and financial analysis engine built on the Django Web Framework.

   Building block Usable You are building a Django product that needs real accounting inside it.

   ★ 1.4k GPL-3.0 Python Active, pushed 4 days ago
4. 4
   Pgledger pgr0ss

   A double entry ledger implementation in PostgreSQL

   Building block Usable Your app runs on Postgres and needs an internal money ledger without adding a separate service.

   ★ 495 MIT Go Active, pushed 12 days ago
5. 5
   Sequence hoophq

   Immutable, scalable, and easy to use ledger service.

   Building block Experimental You want to study or prototype a tamper-evident ledger service.

   ★ 512 Apache-2.0 Clojure Slowing, pushed 3 months ago
6. 6
   DoubleEntry envato

   A double-entry accounting system for Ruby applications.

   Building block Production-ready Your Rails app moves money between users or accounts and needs reliable balances.

   ★ 460 MIT Ruby Slowing, pushed 10 months ago
7. 7
   Medici flash-oss

   Double-entry accounting system for nodejs + mongoose

   Building block Usable Your Node.js app already uses MongoDB and needs an internal ledger for balances or wallets.

   ★ 361 MIT TypeScript Slowing, pushed 3 months ago
8. 8
   Ledger abivia

   General Ledger and Journal Accounting Package and API for Laravel

   Building block Experimental You need a general ledger inside a Laravel app and can maintain the code yourself.

   ★ 132 MIT PHP Quiet, pushed 3 years ago

Commercial double-entry ledger engines

1. 1
   Modern Treasury Ledgers Modern Treasury

   Track every transaction in real-time with double-entry accounting. Built for teams that need perfect accuracy and auditability.

   Building block Production-ready A fintech or platform team needs an auditable ledger for customer balances and does not want to build one.

   Commercial
2. 2
   Fragment Fragment

   Fragment is the financial system for agents. Programmable money that bills, pays, and accounts for itself.

   Building block Usable A product team wants to define its ledger as code and query balances through GraphQL instead of building a ledger.

   Commercial