!banner

Midaz is a composable core banking platform built around a double-entry ledger. One Go monorepo ships the ledger core (onboarding, transactions, CRM, fees), real-time transaction validation and fraud prevention (Tracer) — all under the Elastic License 2.0, source-available. Transactional messaging (PIX, cards, wires) and governance integrations remain external and plug in via the marketplace.

What's in the Box

• Ledger core (one binary): double-entry accounting over the full financial hierarchy — onboarding (organizations, ledgers, assets, portfolios, segments, accounts), n:n transactions, CRM (holders and instruments) with field-level encryption and searchable hashing so PII stays queryable without exposing plaintext, and in-process fee calculation on the transaction path.
• Tracer: real-time transaction validation and fraud prevention — a CEL rule engine, multi-scope spending limits, and a hash-chained immutable audit trail for compliance.

Quickstart

Prerequisites: Go 1.27.0+ and Docker.

git clone https://github.com/LerianStudio/midaz.git
cd midaz
make set-env   # create .env files from .env.example
make up        # start infra, then all services

Services after make up:

| Service | URL | | --- | --- | | Ledger API | http://localhost:3002 | | Tracer | http://localhost:4020 |

Full guide, API references, and best practices: docs.lerian.studio.

Architecture

Both Go units build from the single root module (github.com/LerianStudio/midaz/v4) and ship under a single unified version.

| Unit | Port | Role | Stores | | --- | --- | --- | --- | | Ledger | :3002 | Unified binary: onboarding + transaction + CRM + fees, in-process | PostgreSQL, MongoDB, Valkey, RabbitMQ | | Tracer | :4020 | Real-time validation/fraud: CEL rules, spending limits, hash-chained audit | PostgreSQL | | Infra | — | docker-compose stack | — |

Infrastructure: PostgreSQL 17 (primary/replica), MongoDB replica set, RabbitMQ, Valkey, and Grafana/OpenTelemetry.

The ledger reaches Tracer over an opt-in reservation seam, enabled by setting TRACER_BASE_URL. The transport is gRPC by default with a selectable REST fallback (TRACER_TRANSPORT), authenticated by mutual TLS (TRACER_TLS_MODE=mtls) or delegated to a service-mesh sidecar (mesh), forwarding a trusted x-tenant-id for per-tenant pool resolution. See docs/architecture/ledger-tracer-topology.md.

CRM routes register under the midaz authorization namespace; the coordinated tenant-manager RBAC policy migration is the X1 release gate (see docs/auth/RBAC-NAMESPACES.md).

Executable ledger transactions use the private accounting engine by default: Go composes declarative postings and the Redis/Lua adapter performs live balance validation and mutation in one isolated execution. Receipts and a dedicated recovery queue allow durable SQL/MongoDB completion without reapplying accounting. See docs/architecture/engine.md.

Domain Hierarchy

• Organizations — top-level entities, optionally with parent-child relationships.
• Ledgers — financial record-keeping systems belonging to organizations.
• Assets — types of value (currencies, securities) with specific codes.
• Portfolios — collections of accounts for organizational purposes.
• Segments — categories for grouping accounts (e.g. by department or product line).
• Accounts — basic units for tracking financial resources, linked to assets.
• Transactions — debits and credits, balanced by double-entry rules.
• Balances — available and on-hold amounts tracked per account.

Key Capabilities

• Double-entry engine — every credit has a matching debit.
• Multi-asset support — transactions across currencies with automatic rate conversion.
• Complex transactions — n:n operations (multiple sources to multiple destinations).
• Immutable records — every transaction is permanently recorded for audit.
• Async processing — event-driven transaction handling via RabbitMQ.
• Atomic live-state accounting — balance validation, overdraft arithmetic, mutations, versions, receipts, and recovery evidence execute in one Redis/Lua boundary without stale-state retries.
• Hexagonal + CQRS — domain logic isolated from adapters; commands and queries separated.
• OpenAPI docs — RESTful endpoints with generated OpenAPI specifications.

Community & Support

• Join our Discord community for discussions, support, and updates.
• For bug reports and feature requests, please use our GitHub Issues.
• If you want to raise anything to the attention of the community, open a Discussion in our GitHub.
• Follow us on Twitter for the latest news and announcements.

Repo Activity

!Alt

Contributing & License

We welcome contributions from the community. Read our Contributing Guidelines to get started. Lerian Midaz is released under the Elastic License 2.0 (ELv2) — a source-available license that allows you to use, copy, modify, and redistribute Midaz, with three primary limitations: you may not provide it to others as a managed/hosted service, circumvent its license key functionality, or remove/obscure license notices.

About Lerian

Midaz is developed by Lerian, a tech company founded in 2024. Our team has a track record in developing ledger and core banking solutions. For inquiries or support, reach out at [email protected] or open a Discussion in our GitHub repository.