Open Source • BIAN v14 • Apache-2.0

Xenon — BIAN-aligned banking orchestration platform

Xenon is VecPay-tech's reference implementation of a BIAN v14-aligned banking orchestration platform: event-driven microservices, multi-engine workflow orchestration (Temporal + Flowable), an externalized Decision Service (Flowable DMN), and a unified, role-based operations portal built as a React micro-frontend.

View on GitHub See Screenshots

Java 21 / Spring Boot 4 React 18 + Vite Module Federation Temporal Flowable BPMN/DMN Kafka Outbox 258 BIAN domains, 35 graduated

Overview

What Xenon is and why it exists

Xenon combines governance documentation, a runnable backend platform, and a unified operations portal in a single repository. It is designed as a demonstrable, contract-first reference architecture for banks and fintechs building on the BIAN service landscape — not a toy demo, but a platform with real transactional outbox event publication, maker-checker approval workflows, JWT-based OAuth2 security, and a full five-layer test standard applied per domain service.

The platform currently runs locally on Docker/Podman Compose for development and demos; production targets AWS EKS, MSK, and Aurora (see the project's Architecture Decision Records for the full rationale).

Architecture

Five runtime concerns, each with a distinct owner

Concern	Technology
Distributed machine workflows and sagas	Temporal
Human approvals, exceptions, SLA tasks	Flowable BPMN/CMMN
Policy externalization (eligibility, routing, thresholds)	Decision Service (Flowable DMN)
Event streaming and CEP analytics	Kafka + Flink (Phase 2)
Unified operations portal (role-based, multi-domain UI)	React 18 + Vite Module Federation

Domain services are BIAN-aligned, contract-first microservices — OpenAPI and AsyncAPI are the source of truth for interfaces. Every state-changing write goes through a transactional outbox (never a direct Kafka publish inside a transaction), and every domain service must satisfy a five-layer test standard: controller unit tests, service integration tests, outbox relay tests, and consumer/provider Pact contract tests.

Screenshots

The unified operations portal, captured from a running local instance

Decision Rules list page showing deployed DMN and BPMN artifacts — Decision Rules — DMN decision tables and BPMN process models a domain evaluates against, each versioned and independently publishable.

DMN decision table editor showing a loan pre-qualification rule — DMN rule editor — visual decision-table authoring for policy rules (e.g. credit pre-qualification), gated by a maker-checker approval workflow.

BPMN process editor showing a customer onboarding workflow — BPMN process viewer — human-task workflows such as customer onboarding, modeled and versioned alongside the DMN rules they invoke.

Decision audit trail listing evaluated decisions with outcome and risk band — Decision audit — every DMN evaluation is logged with outcome, risk band, matched rule IDs, and latency for full explainability.

Corporate Loan domain list page in English — Corporate Loan domain workspace — one of 35 graduated BIAN domain services, each with its own list/detail/approval-queue pages.

Same Corporate Loan domain list page switched to Traditional Chinese — Built-in i18n — English, Traditional Chinese, and Japanese are supported platform-wide, switchable without a page reload.

Governance & Rule Authoring

Maker-checker controls for policy rule changes

Business rules (DMN decision tables) and process models (BPMN diagrams) are authored directly in the portal by operations users, then routed through a compliance approval queue before publication. Every draft carries a compatibility report and a test report generated against the rule's existing test cases, and every approve/reject action requires a recorded rationale — satisfying the platform's 100%-audit-coverage requirement for privileged, financial state-changing actions.

Getting Started

Run the full stack locally with Docker Compose

git clone https://github.com/VecPay-tech/xenon.git
cd xenon

# Backend platform (Java 21 / Maven monorepo)
cd platform
mvn clean install -DskipTests          # ~20s, 28+ modules

# Full stack (Postgres, Kafka, Keycloak, Temporal, gateway, domain services)
cd ..
docker compose --profile platform up -d

# Unified operations portal (React micro-frontend, pnpm workspace)
cd portal
pnpm install
pnpm --filter shell dev                # http://localhost:3010

See the repository's README.md and CLAUDE.md for the full developer onboarding runbook, domain graduation checklist, and non-functional release gates.

Repository Structure

A single repo for governance docs, backend, and portal

Directory	Role
`docs/`	Normative standards, contracts, schemas, ADRs, governance artifacts
`platform/`	Maven monorepo implementing all domain services (Java 21, Spring Boot 4)
`portal/`	pnpm workspace implementing the Unified Operations Portal (React 18, Vite Module Federation)
`bian/`	The BIAN v14 service landscape reference used to derive domain contracts

Status & Roadmap

Where the platform stands today

35 of 258 catalogued BIAN domains are fully graduated (real entities, migrations, outbox-backed writes, gateway routes, and full five-layer test coverage), including Payment Execution, Customer Profile, Decision Service, Beneficiary Management, Current Account, and Corporate Loan. The remainder are scaffolded and boot with health checks only, ready to be graduated using the platform's mechanical graduation pipeline.

Deferred to later phases: a shared demo environment on Oracle OCI, AWS EKS/MSK/Aurora production deployment, and Apache Flink-based complex event processing.