Software Requirements & Specifications

This document specifies the software requirements, dependencies, and technical specifications for developing and deploying the Dharini platform.

Runtime Requirements

Backend

Component	Version	Notes
Node.js	22.x LTS	Required for NestJS runtime
PostgreSQL	16.x	With PostGIS 3.4 extension
Redis	7.x (Alpine)	For BullMQ job queues

Web Frontend

Component	Version	Notes
Node.js	22.x LTS	Required for Next.js
Browser Support	Chrome 90+, Firefox 90+, Safari 14+, Edge 90+	Modern browsers with ES2020 support

Mobile App

Component	Version	Notes
Flutter SDK	≥3.16.0	Cross-platform framework
Dart SDK	^3.5.4	Language runtime
Android	API 21+ (Android 5.0)	Minimum supported version
iOS	12.0+	Minimum supported version (planned)

Development Environment

Prerequisites

Tool	Version	Purpose
Docker	24.x+	Container runtime
Docker Compose	2.x+	Multi-container orchestration
Git	2.x+	Version control
Node.js	22.x LTS	Backend and web development
Flutter SDK	≥3.16.0	Mobile development
Android Studio	Latest	Android SDK and emulator
VS Code / IDE	Latest	Recommended IDE

Quick Start (Development)

# Clone repository
git clone https://github.com/dsih-artpark/dharini.git
cd dharini

# Copy environment template
cp .env.example .env

# Start development services
docker compose --profile development up -d

# Run database migrations
docker exec -it backend npm run migration:run

Development Ports

Service	Port	URL
Backend API	4000	http://localhost:4000
Web Frontend	3000	http://localhost:3000
APK Server	3001	http://localhost:3001
PostgreSQL	5432	localhost:5432
Redis	6379	localhost:6379
pgAdmin	5050	http://localhost:5050

Production Environment

Infrastructure Requirements

Component	Specification	Notes
Compute	2 vCPU, 4GB RAM minimum	t3.medium or equivalent
Database	PostgreSQL 16 with PostGIS	AWS RDS recommended
Storage	50GB+ SSD	For database, logs, APKs
Object Storage	S3-compatible	For media uploads
SSL	TLS 1.2+	Required for HTTPS

AWS Services (Recommended)

Service	Purpose
EC2	Application hosting
RDS	Managed PostgreSQL
S3	File storage (photos, reports)
Route 53	DNS management
ACM	SSL certificates

Network Requirements

Port	Protocol	Purpose
22	TCP	SSH access (restricted)
80	TCP	HTTP (redirects to HTTPS)
443	TCP	HTTPS
5432	TCP	PostgreSQL (internal only)

Software Dependencies

Backend (NestJS)

Core Framework:

NestJS 11.x
TypeScript 5.x
TypeORM 0.3.x

Key Dependencies:

Package	Version	Purpose
`@nestjs/passport`	11.x	Authentication
`@nestjs/jwt`	11.x	JWT tokens
`@nestjs/bullmq`	11.x	Job queue
`@casl/ability`	6.x	Authorization (RBAC)
`@aws-sdk/client-s3`	3.x	S3 file uploads
`typeorm`	0.3.x	Database ORM
`pg`	8.x	PostgreSQL driver
`nodemailer`	7.x	Email sending
`twilio`	5.x	SMS/OTP

Web Frontend (Next.js)

Core Framework:

Next.js 15.x (App Router)
React 18.x
TypeScript 5.x

Key Dependencies:

Package	Version	Purpose
`jotai`	2.x	State management
`axios`	1.x	HTTP client
`leaflet`	1.9.x	Maps
`react-leaflet`	4.x	React map components
`recharts`	2.x	Charts/visualization
`tailwindcss`	3.x	Styling
`posthog-js`	1.x	Analytics

Mobile (Flutter)

Core Framework:

Flutter ≥3.16.0
Dart ^3.5.4

Key Dependencies:

Package	Version	Purpose
`flutter_bloc`	8.x	State management
`flutter_hooks`	0.20.x	Hooks for widgets
`fquery`	1.5.x	Data fetching/caching
`hive`	2.x	Local database
`dio`	5.x	HTTP client
`go_router`	14.x	Navigation
`geolocator`	13.x	GPS location
`mobile_scanner`	6.x	QR/barcode scanning
`sentry_flutter`	9.x	Error tracking
`posthog_flutter`	5.x	Analytics

Database Schema

Core Entities

Table	Description	Key Relations
`users`	User accounts	→ teams, roles
`projects`	Surveillance projects	→ teams, sites, diseases
`teams`	Team organization	→ users, projects
`roles`	Permission definitions	→ users (via user_roles)
`sites`	Collection locations	→ projects, visits (PostGIS geometry)
`visits`	Site visit records	→ sites, samples, users
`samples`	Sample records	→ visits, lab_tests, diseases
`lab_tests`	Test results	→ samples, diseases
`diseases`	Disease definitions	→ projects, samples
`sample_types`	Sample type catalog	→ samples
`media`	Uploaded files	→ S3 references

Required Extensions

CREATE EXTENSION IF NOT EXISTS postgis;
CREATE EXTENSION IF NOT EXISTS postgis_topology;
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

API Specifications

Authentication

Method: JWT Bearer tokens
Token Expiry: 24 hours (configurable)
OTP Delivery: SMS via Twilio or email via SMTP

API Documentation

Format: OpenAPI 3.0 (Swagger)
Endpoint: /api/docs (development/staging)
Generated Client: es_client package for mobile

Rate Limiting

Endpoint	Limit	Window
Auth endpoints	10 requests	15 minutes
API endpoints	100 requests	15 minutes
File uploads	20 requests	15 minutes

Security Requirements

Authentication

OTP-based login (SMS/email)
JWT tokens with RS256 or HS256
Secure httpOnly cookies for web sessions
Token refresh mechanism

Authorization

Role-based access control (CASL)
Scope hierarchy: System → Project → Team
Policy-based guards on all endpoints

Data Protection

HTTPS/TLS 1.2+ required
Database encryption at rest (RDS)
S3 bucket encryption (SSE-S3)
Sensitive data masked in logs

Compliance

Audit logging for all data changes
User attribution on all operations
Data retention policies configurable

Performance Specifications

Response Times (P95)

Operation	Target
API read operations	< 200ms
API write operations	< 500ms
File uploads (< 5MB)	< 3s
Dashboard load	< 2s

Scalability

Metric	Capacity
Concurrent users	500+
Samples per project	100,000+
Daily API requests	100,000+
Storage (media)	Unlimited (S3)

Offline Capability

Mobile app supports full offline operation
Local Hive database for data persistence
Automatic sync on connectivity restore
Photo compression (1MB max, 1920px)

Monitoring & Observability

Error Tracking

Service: Sentry
Coverage: Backend, web, mobile
Alerts: Critical errors trigger notifications

Analytics

Service: PostHog
Events: User actions, feature usage
Privacy: Configurable data collection

Health Checks

Endpoint	Purpose
`/health`	Backend liveness
`/api/docs`	API availability
APK server `/health`	Distribution service

Logging

Structured JSON logs (production)
Log levels: error, warn, info, debug
Retention: 30 days (configurable)

Environment Variables

See Environment Variables Reference for the complete list of configuration options.

Required Variables

# Database
DB_HOST, DB_PORT, DB_USERNAME, DB_PASSWORD, DB_DATABASE

# Redis
REDIS_HOST, REDIS_PORT

# Security
JWT_SECRET

# AWS S3
S3_REGION, S3_BUCKET, S3_ACCESSKEYID, S3_SECRETACCESSKEY

# Frontend
NEXT_PUBLIC_API_URL, NEXT_PUBLIC_APP_ENV

Deployment Profiles

Docker Compose supports multiple deployment profiles:

Profile	Services	Use Case
`development`	All + pgAdmin + local Postgres	Local development
`demo`	All + local Postgres	Demo environments
`staging`	Backend, frontend, APK, Redis	Staging (external DB)
`production`	Backend, frontend, APK, Redis	Production (external DB)

# Development
docker compose --profile development up -d

# Production
docker compose --profile production up -d

Version Compatibility Matrix

Component	Current Version	Minimum Supported
Backend API	0.1.0	0.1.0
Web Frontend	0.1.0	0.1.0
Mobile App	0.2.0-beta4	0.2.0-beta1
Database Schema	Migration-based	Latest migration

Document generated from production branch. Last updated: March 2026.