Hysen Labsopen-bank-oss
Cloud-native, open-source retail banking platform reference implementation (Kotlin/Quarkus, Next.js, event-driven microservices).
OpenBank is an open source retail banking reference platform
OpenBank is an early stage, community driven reference implementation of a retail bank built on Kotlin, Quarkus, Next.js, and event driven microservices.
Architecture and scope
OpenBank demonstrates how a modern retail bank can be built with domain driven design, hexagonal microservices, double entry ledger accounting, PSD2 compliance, machine enforced governance, and end to end observability. The repository holds about 37 backend microservices, all deployed to an AWS sandbox. The intra bank money path is end to end, and the ISO 20022 pipeline and clearing simulator are wired together.
Current status
The project is in beta with milestone one complete and milestones two, three, and five in progress. Core domain services for account, ledger, transaction, and balance are implemented, tested, and deployed. Intra bank payments run end to end from a Temporal workflow through the ledger to balances. Interbank rails such as SEPA, domestic, instant, and clearing are partially wired, but live interbank network connections are later milestones. The PSD2 consent, strong customer authentication, and XS2A developer portal are live.
Governance and licensing
OpenBank bakes governance, supply chain security, and AI agent operations in as code, and tracks OpenSSF Scorecard and Best Practices badges. It is licensed as Apache-2.0 for the platform, while AI agent services use AGPL-3.0 only plus a commercial option. The README states clearly that the project is not production ready and is not licensed to operate as a bank; someone needs the appropriate banking licence and capital to deploy it.
Editorial conclusion
OpenBank is written in Kotlin with a Next.js front end, licensed under Apache-2.0 for the platform, and is explicitly described as not production ready in its README.
Community notes