A production-style fintech platform built as a polyglot microservices monorepo. Covers authentication, wallet management, payments, KYC, fraud detection, analytics, social features, webhooks, an admin console, and a tamper-proof audit log.
Looking for the original version built with Express, MongoDB, RabbitMQ, and React? See the v1 branch.
A Next.js 15 app serves both the user-facing product and the admin console through the same nginx gateway.
Dashboard — wallet balance, recent activity, quick deposit & send |
Analytics — category spend, breakdown, top merchants, budget tracking |
Notifications — real-time activity feed via SSE |
Identity Verification — tier progression, document upload, active limits |
Admin — KYC Management — pending review queue, document inspection, approve / reject |
|
| Service | Stack | Port | Description |
|---|---|---|---|
| web | Next.js 15 | 3000 | User app and admin console |
| auth | Python / FastAPI | 4001 | JWT issuance, refresh, RBAC |
| wallet | Python / FastAPI | 4002 | Balances, gRPC settlement interface |
| transactions | NestJS | 4003 | Transfers, top-ups, idempotency |
| fraud | NestJS (gRPC only) | — | Real-time fraud scoring on every transaction |
| kyc | NestJS | 4004 | Document upload, tier management |
| analytics | NestJS | 4005 | Spend insights, category budgets |
| notifications | NestJS | 4006 | Persistent notifications + SSE stream |
| social | NestJS | 4007 | Contacts, money requests, bill splits |
| webhook | NestJS | 4008 | User-registered webhooks + delivery log |
| admin | NestJS | 4009 | Admin console API |
| audit | NestJS | 4010 | Immutable append-only audit log |
# Generate RSA keys (first time only)
sh scripts/generate-keys.sh
# Start everything
docker compose -f docker-compose.dev.yml up -d --buildThe app is at http://localhost. The admin console is at http://localhost/app-admin.
Create an admin user:
docker exec -it mint-auth uv run python /app/apps/auth/src/create_admin.py \
--email admin@mint.dev \
--password adminpass \
--name "Admin User"Migrations run automatically on startup. Swagger UI is at /api-docs on every service.
Every service exports OpenTelemetry traces to a local collector. Trace context is propagated across HTTP, gRPC, and Kafka — a single transfer produces one trace spanning fraud scoring, wallet settlement, analytics ingestion, notification delivery, and webhook dispatch.
Grafana is at http://localhost:4000.
Full documentation at sreekarnv.github.io/mint.
- Architecture — service map, communication patterns, auth flow, transfer flow
- Design Decisions — polyglot rationale, gRPC vs Kafka, idempotency, fraud scoring, audit immutability
- Services — endpoints, databases, Kafka topics per service
- Infrastructure — nginx, Kafka, Postgres, Redis, MinIO, observability
- Running — dev and production setup