midaz

Lerian Midaz is a composable core banking platform built around a double-entry ledger, delivered as a single Go monorepo. It includes a ledger core handling onboarding, transactions, CRM, and fees, plus Tracer for real-time transaction validation and fraud prevention. The platform supports multi-currency and multi-asset transactions with n:n capabilities, immutable audit records, and async processing via RabbitMQ. It uses a hexagonal architecture with CQRS, and offers OpenAPI documentation. Infrastructure includes PostgreSQL, MongoDB, Valkey, and RabbitMQ, with optional Grafana/OpenTelemetry monitoring. The ledger and Tracer communicate via an opt-in gRPC reservation seam with mutual TLS. Licensed under Elastic License 2.0 (source-available), it allows use, modification, and redistribution with restrictions on managed hosting and license key circumvention. Quickstart requires Go 1.27.0+ and Docker, with services accessible at localhost:3002 (Ledger API) and localhost:4020 (Tracer).