DAMSLE

Digital Asset Marketplace & SaaS Licensing Engine

A production-grade, open-source Go boilerplate for building digital asset marketplaces with automated license management. Three decoupled microservices, event-driven architecture, and zero-dependency frontend.

Features

• Clean Architecture: Decoupled microservices (cart, payment, license)
• Event-Driven: Built on NATS JetStream for reliable async messaging
• High Performance: DragonflyDB for ultra-fast caching and distributed locking
• Payment Abstraction: Seamless support for Stripe and LemonSqueezy
• Modern UI: Zero-dependency vanilla HTML/CSS/JS frontend dashboard

Quick Start

Docker Compose:

git clone https://github.com/vyofgod/DAMSLE.git
cd DAMSLE
docker compose up -d

Then open http://localhost:8080 for the frontend.

Installation Methods

Option 1: Python CLI & SDK (PyPI)

Install the management tool and developer SDK instantly:

pip install damsle

Manage your stack with ease:

damsle up      # Start the infrastructure
damsle ps      # Check service status
damsle down    # Stop everything

Option 2: Docker Compose (Manual)

Start all services and infrastructure instantly:

docker compose up -d

Verify services are running:

curl http://localhost:8081/healthz  # Cart
curl http://localhost:8082/healthz  # Payment
curl http://localhost:8083/healthz  # License

Option 2: Local Development

Start infrastructure only:

docker compose up -d nats dragonflydb

Run services (in separate terminals):

cd services/cart && go run ./cmd/server
cd services/payment && go run ./cmd/server
cd services/license && go run ./cmd/server

Serve frontend:

cd web && python3 -m http.server 8080

Option 3: Kubernetes Deployment

Deploy to your K8s cluster:

kubectl apply -f deploy/k8s/namespace.yaml
kubectl apply -f deploy/k8s/nats/
kubectl apply -f deploy/k8s/dragonflydb/
kubectl apply -f deploy/k8s/cart-service/
kubectl apply -f deploy/k8s/payment-service/
kubectl apply -f deploy/k8s/license-service/
kubectl apply -f deploy/k8s/ingress.yaml

Usage

1. Manage Cart

• Interact with the Cart Service on :8081
• Endpoints: GET /api/v1/cart/{id}, POST /api/v1/cart/{id}/items
• Perform checkout: POST /api/v1/cart/{id}/checkout

2. Process Payments

• Handled by Payment Service on :8082
• Verify payment status: GET /api/v1/payments/{id}
• Receives provider webhooks (e.g., Stripe) at /api/v1/payments/webhook

3. Issue & Validate Licenses

• Governed by License Service on :8083
• Create products: POST /api/v1/products
• Validate issued keys: POST /api/v1/licenses/validate

Architecture & Specifications

System Design

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│    Cart     │     │   Payment   │     │   License   │
│   Service   │     │   Service   │     │   Service   │
│   :8081     │     │   :8082     │     │   :8083     │
└──────┬──────┘     └──────┬──────┘     └──────┬──────┘
       │                   │                   │
       └───────────┬───────┴───────────┬───────┘
                   │                   │
             ┌─────┴─────┐      ┌──────┴──────┐
             │   NATS    │      │ DragonflyDB │
             │ JetStream │      │  (Redis)    │
             └───────────┘      └─────────────┘

Event Flow

• cart.checkout → payment.completed → license.issued

Tech Stack

• Language: Go 1.23
• Cache / Store: DragonflyDB (Redis-compatible)
• Locking: Distributed mutex via bsm/redislock
• Frontend: Vanilla HTML/CSS/JS

Configuration

All configuration is handled via environment variables:

• PORT: Service port (8081/8082/8083)
• NATS_URL: NATS server URL (default: nats://localhost:4222)
• DRAGONFLY_ADDR: DragonflyDB address (default: localhost:6379)
• PAYMENT_PROVIDER: Provider choice (stripe or lemonsqueezy)
• STRIPE_SECRET_KEY / STRIPE_WEBHOOK_SECRET: Stripe credentials
• LICENSE_KEY_SECRET: HMAC secret for key generation
• LOG_LEVEL: Logging verbosity (debug, info, warn, error)

Python SDK Usage

Integrate DAMSLE into your Python applications with ease:

from damsle import DamsleClient

client = DamsleClient("http://localhost:8083")

# Validate a license key
result = client.validate_license(
    product_id="my-product-uuid",
    license_key="ABCD-1234-EFGH"
)

if result.get("valid"):
    print("Welcome, licensed user!")
else:
    print(f"Access denied: {result.get('message')}")

Important Notes

• Secret Management - Ensure LICENSE_KEY_SECRET and payment API keys are kept secure
• Event Idempotency - Services are designed to handle duplicate events safely
• Data Persistence - DragonflyDB is used for caching, configure persistence if required for production

Links

• GitHub: https://github.com/vyofgod/DAMSLE
• Issues: https://github.com/vyofgod/DAMSLE/issues

Contributing

Contributions welcome! Please submit a Pull Request.

License

MIT License - see LICENSE file for details.

Disclaimer

This software is provided "as is" without warranty. Ensure proper testing in staging environments before deploying to production.

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Empowering Digital Commerce with DAMSLE

Version 1.0.0