# Formance Ledger 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](https://docs.formance.com/modules/numscript/introduction), 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](https://www.formance.com/). 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. ## Localhost ⚡ 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: ```shell # 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](http://localhost:3000/formance/localhost?region=localhost):  ## Production 🛡️ Production usage of the Formance Ledger is (only) supported through the official k8s [operator](https://github.com/formancehq/operator) deployment mode. Follow the [installation instructions](https://docs.formance.com/build/deployment/operator/installation) to learn more. ## Artifacts 📦 Standalone binary builds can be downloaded from the [releases page](https://github.com/formancehq/ledger/releases). Container images can be found on the [ghcr registry](https://github.com/formancehq/ledger/pkgs/container/ledger). ## Docs 📚 You can find the exhaustive Formance Platform documentation at [docs.formance.com](https://docs.formance.com). ## Community 💬 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](https://github.com/orgs/formancehq/discussions) - looking forward to see you there! ## Contributing 🛠️ See [CONTRIBUTING.md](./CONTRIBUTING.md)