Formance Ledger is a programmable financial core ledger that provides a foundation for all kind of money-moving applications. It provides an atomic multi-postings transactions system, account-based modeling, and is programmable in numscript, a built-in DSL to model financial transactions.

The ledger can be used either as a standalone micro-service or as part of the Formance Platform. It will shine for financial applications requiring a centralized state-keeping of the assets they orchestrate, such as:

• Users balances holding apps, where the ownership of funds held in FBO accounts need to be fine-grained in a ledger
• Digital assets platforms and exchanges, where funds in various denominations are represented
• Payment systems, where funds are cycled through a series of steps from acquiring to payouts
• Loan managment systems, where a sophisticated structure of amounts dues and to be disbursed are orchestrated

Is uses PostgreSQL as its main transactional storage layer and comes with a built-in mechanism to ship ledger logs to replica data stores for OLAP optimized querying.

To quickly get started using the Formance Ledger on your computer, you can use the local-optimized, all-in-one docker image:

docker compose -f examples/standalone/docker-compose.yml up

Which will start:

• A Postgres DB
• 1 Gateway Server process (Caddy based reverse proxy)
• 1 Ledger server process
• 1 Ledger worker process
• The Console UI

With the system is up and running, you can now start using the ledger:

# Create a ledger
http POST :8080/api/ledger/v2/quickstart
# Create a first transaction
http POST :8080/api/ledger/v2/quickstart/transactions postings:='[{"amount":100,"asset":"USD/2","destination":"users:1234","source":"world"}]'

And get a visual feedback on the Ledger Console UI started on http://localhost:3000/formance/localhost?region=localhost:

Production usage of the Formance Ledger is (only) supported through the official k8s operator deployment mode. Follow the installation instructions to learn more.

Standalone binary builds can be downloaded from the releases page. Container images can be found on the ghcr registry.

You can find the exhaustive Formance Platform documentation at docs.formance.com.

If you need help, want to show us what you built or just hang out and chat about ledgers you are more than welcome in our GitHub Discussions - looking forward to see you there!

See CONTRIBUTING.md