LexCam — AI-Powered Legal Aid Platform for Cameroon

SEN3244 Software Architecture | Spring 2026 | ICT University Team: 2 members | VPS: Contabo Cloud VPS 10 (4 vCPU, 8GB RAM) | Orchestration: K3s

LexCam is a bilingual (French/English) Progressive Web App that gives Cameroonian citizens access to legal information, verified lawyer referrals, and formally generated legal documents — all powered by a RAG AI pipeline and deployed on Kubernetes.

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Architecture

LexCam uses a Microservices + Event-Driven Hybrid architecture.

Browser (Next.js PWA)
    │
    ▼
UFW Firewall (Contabo VPS)
    │
    ▼
Traefik Ingress Controller (K3s built-in) — TLS termination
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Kong API Gateway — routing, rate limiting, auth middleware
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Microservices Layer (11 services)
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    ├── User Management (8001)      ─ auth, JWT, OTP, profiles
    ├── Lawyer Service (8002)       ─ directory, referrals, verification
    ├── Knowledge Base (8003)       ─ law storage, vector + keyword search
    ├── RAG Service (8004)          ─ AI Legal Assistant, SSE streaming
    ├── Embedding Service (8005)    ─ multilingual-e5-small, 384-dim vectors
    ├── Document Service (8006)     ─ PDF generation, pay-first policy
    ├── Payment Service (8007)      ─ Campay Mobile Money integration
    ├── Notification Service (8008) ─ SMTP email dispatch
    ├── Feedback Service (8009)     ─ AI response ratings, auto-flagging
    ├── Admin Panel (8010)          ─ internal Django Admin
    └── Scraper Service (8011)      ─ lawyer directory crawler

Event Bus: RabbitMQ (topic exchange lexcam.events + DLX)
Workers:   Doc Worker | Notification Worker | Lawyer Ingest | Indexing Worker
Databases: PostgreSQL (10 schemas) | Qdrant | MinIO | Redis

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Features

Feature	Description
AI Legal Assistant	RAG pipeline — Qdrant retrieval + Groq Llama 3.3 70B, SSE token streaming, bilingual
Law Explorer	Dual search (Qdrant vector + PostgreSQL tsvector), Reciprocal Rank Fusion, plain-language summaries
Lawyer Directory	Self-registered verified lawyers + scraped listings; city + specialization filters
Referral System	Citizen → lawyer referral with contact reveal on acceptance
Document Generator	Pay-first PDF generation (WeasyPrint), Campay MTN/Orange Mobile Money
Admin Panel	Lawyer verification, scraper trigger, flagged AI review, audit log
Notifications	Event-driven email for all workflow events
Feedback Loop	Per-response ratings, auto-flag at 3× not_helpful, admin review

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Technology Stack

Layer	Technology
Frontend	Next.js 14 App Router, Tailwind CSS, PWA
AI Framework	FastAPI + LangChain + Groq (Llama 3.3 70B / 3.1 8B)
Embedding	intfloat/multilingual-e5-small (384-dim, French + English)
Business Services	Django 4.2 + Django REST Framework
Databases	PostgreSQL 15, Qdrant, MinIO, Redis 7
Message Bus	RabbitMQ 3 (topic exchange + DLX)
Orchestration	K3s (lightweight Kubernetes)
Ingress	Traefik (K3s built-in) + Kong API Gateway
CI/CD	Jenkins (7-stage pipeline, GHCR image push)
Monitoring	Prometheus + Grafana + Node Exporter
IaC	Ansible (VPS provisioning + K3s deployment)
Packaging	Helm Charts (one per service)
Payment	Campay API (MTN Mobile Money + Orange Money)
Email	Gmail SMTP

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Repository Structure

lexcam/
├── services/               # 11 backend microservices
│   ├── user-management/    # Django — auth, JWT, OTP
│   ├── lawyer-service/     # Django — directory, referrals
│   ├── knowledge-base-service/ # FastAPI — law storage, dual search
│   ├── rag-service/        # FastAPI — AI pipeline, SSE streaming
│   ├── embedding-service/  # FastAPI — multilingual-e5-small
│   ├── document-service/   # Django — PDF generation
│   ├── payment-service/    # Django — Campay integration
│   ├── notification-service/ # Django — SMTP email
│   ├── feedback-service/   # Django — ratings, flagging
│   ├── admin-panel/        # Django Admin — internal
│   └── scraper-service/    # Django — lawyer crawler
├── workers/                # 4 background worker pods
│   ├── doc-worker/         # payment.confirmed → WeasyPrint PDF
│   ├── notification-worker/# events → SMTP email
│   ├── lawyer-ingest-worker/ # lawyers.scraped → bulk insert
│   └── indexing-worker/    # corpus.updated → Qdrant upsert
├── frontend/               # Next.js 14 PWA
├── infrastructure/
│   ├── helm/               # Helm charts (one per service)
│   ├── k8s/                # Raw K8s manifests (databases, monitoring)
│   └── ansible/            # VPS provisioning playbooks
├── Jenkinsfile             # 7-stage CI/CD pipeline
├── docker-compose.dev.yml  # Local development stack
└── README.md

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Local Development Setup

Prerequisites

• Docker Desktop
• Node.js 20+
• Python 3.12+

1. Start infrastructure services

docker-compose -f docker-compose.dev.yml up -d

This starts: PostgreSQL, Qdrant, Redis, RabbitMQ, MinIO.

2. Run a backend service

cd services/user-management
pip install -r requirements.txt
cp .env.example .env      # fill in values
python manage.py migrate
python manage.py runserver 0.0.0.0:8001

Swagger UI available at: http://localhost:8001/api/v1/docs/

3. Run the frontend

cd frontend
npm install
npm run dev

Frontend at: http://localhost:3000

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API Documentation

Each service exposes Swagger UI at /api/v1/docs/:

Service	Local URL
User Management	http://localhost:8001/api/v1/docs/
Lawyer Service	http://localhost:8002/api/v1/docs/
Knowledge Base	http://localhost:8003/docs
RAG Service	http://localhost:8004/docs
Embedding Service	http://localhost:8005/docs
Document Service	http://localhost:8006/api/v1/docs/
Payment Service	http://localhost:8007/api/v1/docs/
Notification Service	http://localhost:8008/api/v1/docs/
Feedback Service	http://localhost:8009/api/v1/docs/
Admin Panel	http://localhost:8010/api/v1/docs/
Scraper Service	http://localhost:8011/api/v1/docs/

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Running Tests

# Django services — run from each service directory
pytest --cov=apps --cov-report=html --cov-fail-under=80

# FastAPI services — run from each service directory
pytest --cov=app --cov-report=html --cov-fail-under=80

All services target ≥ 80% code coverage. The Jenkins pipeline fails the build if any service falls below this threshold.

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Production Deployment (K3s on Contabo VPS)

1. Provision the VPS

cd infrastructure/ansible
# Edit inventory/hosts.ini — set your VPS IP
ansible-playbook -i inventory/hosts.ini playbooks/provision-vps.yml
ansible-playbook -i inventory/hosts.ini playbooks/deploy-k3s.yml

2. Apply K8s manifests (databases + monitoring)

kubectl apply -f infrastructure/k8s/namespace.yaml
kubectl apply -f infrastructure/k8s/databases/
kubectl apply -f infrastructure/k8s/monitoring/
kubectl apply -f infrastructure/k8s/gateway/

3. Deploy services via Helm

for chart in infrastructure/helm/*/; do
  name=$(basename $chart)
  helm upgrade --install $name $chart --namespace lexcam
done

4. Verify all pods are running

kubectl get pods -n lexcam

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CI/CD Pipeline (Jenkins)

On every push to main, the Jenkinsfile runs 7 stages:

Stage	Action
1. Checkout	Pull latest code
2. Test	pytest for all 11 services in parallel
3. Coverage	Fail build if any service < 80% coverage
4. Build	docker build all service images
5. Push	Push tagged images to GitHub Container Registry
6. Deploy	helm upgrade --install for all services
7. Health Check	kubectl rollout status for all deployments

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Monitoring

• Prometheus scrapes all pods via prometheus.io/scrape: "true" pod annotations
• Grafana dashboards: Infrastructure, Service Health, Business Metrics
• Node Exporter tracks VPS CPU, RAM, disk, and network
• Access Grafana: http://VPS_IP:3001 (admin / lexcam_dev in dev)

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Project Context

Field	Detail
Course	SEN3244 Software Architecture
Institution	ICT University
Instructor	Engr. TEKOH PALMA
Semester	Spring 2026
Team Size	2 developers
VPS	Contabo Cloud VPS 10 — 4 vCPU, 8GB RAM, 75GB NVMe

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LexCam — Making Cameroonian law accessible to every citizen.