API Development & Integration Services — Connect Everything, Automate Everything
Modern businesses run on APIs. Your CRM needs to talk to your website. Your payment gateway needs to connect to your accounting software. Your WhatsApp needs to sync with your CRM. We build custom APIs and integrate third-party services — turning disconnected systems into a seamlessly connected digital ecosystem.
Why APIs Are Essential for Modern Businesses
Data silos are expensive. When your systems don’t talk to each other, you waste time on manual data entry, duplicate work, and delayed decision-making. APIs break down these silos. They let your systems communicate automatically, reducing errors and saving hours of manual labour. A well-built API strategy turns your fragmented technology stack into an integrated ecosystem.
We’ve built 300+ APIs ranging from simple webhook handlers to complex GraphQL systems serving millions of requests monthly. Our API specialists understand Indian business needs: we’ve integrated Razorpay, WhatsApp Business, Aadhaar verification, GSTN compliance, and custom enterprise systems. Every API we build is documented, versioned, monitored, and built for 99.95% uptime.
Our API Development & Integration Services
🏗️ REST API Development
Scalable, documented, versioned REST APIs for web and mobile applications following RESTful best practices.
⚡ GraphQL API Development
Flexible GraphQL APIs for efficient data fetching in complex applications with automatic query optimization.
🔗 Third-Party API Integration
Connect Razorpay, WhatsApp, Shiprocket, Zoho, Tally, and 100+ other APIs to your systems seamlessly.
🔒 API Security & Authentication
OAuth 2.0, JWT, API key management, rate limiting, CORS configuration for secure API communication.
📊 API Gateway & Management
Kong, AWS API Gateway — centralised API management, analytics, throttling, and monitoring.
🔄 Webhook Development
Event-driven webhooks for real-time data sync between systems — payment confirmations, status updates, notifications.
📖 API Documentation
OpenAPI/Swagger documentation, interactive developer portals, SDK generation for easy API consumption.
🔧 API Modernisation
Migrate legacy SOAP/XML services to modern REST/GraphQL APIs with zero downtime.
Why Choose Xylus Info?
OpenAPI (Swagger) Documentation on Every Project
Every API comes with complete OpenAPI documentation. Developers can understand and integrate easily.
Indian API Specialists
Deep expertise in Indian-specific APIs: Razorpay, PayU, WhatsApp Business, GSTN, Aadhaar verification, TDS reconciliation.
Security-First API Design
OWASP compliance, secure authentication, rate limiting, input validation, SQL injection prevention built into every API.
Versioning & Backward Compatibility
APIs are versioned properly. Updates don’t break existing integrations. Deprecation paths planned in advance.
Load-Tested APIs (10,000+ req/min)
Every API is load-tested to handle peak traffic. Horizontal scaling built in from the start.
Postman Collections & SDK Provided
Postman collections for easy testing. JavaScript, Python SDKs generated automatically for common languages.
Our Development Process
We follow a proven, systematic approach that ensures quality, reliability, and client satisfaction — from the first call to ongoing post-launch support.
Requirements Analysis
Understand what systems need to connect, what data flows between them, security requirements, and performance expectations.
API Design & Specification
Design API endpoints, data models, error handling, and authentication. Create OpenAPI specification before development.
Development
Build API using Node.js, PHP/Laravel, or Python/FastAPI. Implement authentication, validation, error handling.
Security Testing
Security audit, penetration testing, vulnerability scanning. OWASP compliance verification.
Documentation
Generate OpenAPI spec, create Postman collection, write integration guides, generate SDKs.
Deployment & Monitoring
Deploy with auto-scaling configuration. Set up monitoring, alerting, rate limiting, analytics dashboard.
Technologies We Use
We leverage modern, industry-proven technologies for API development:
⚙️ Backend Frameworks
🔗 API Types
📋 Documentation & Testing
🔐 Authentication
🔄 API Gateway
⚡ Caching
Industries We Serve
Our API development expertise spans numerous industries across India and beyond:
Project Success Stories
Logistics Company: Unified API Gateway
Challenge: A logistics company was managing 6 disconnected systems manually. We built a unified API gateway connecting TMS, WMS, billing, CRM, WhatsApp Business, and Shiprocket.
Solution: Unified API gateway connecting all systems with real-time data flow.
Fintech Startup: Multi-API Integration
Challenge: A fintech startup needed instant loan processing. We integrated Razorpay (payments), Aadhaar (verification), CIBIL (credit scoring), and GSTN (income verification) APIs.
Solution: Multi-API integration for automated loan processing and verification.
Frequently Asked Questions
Related Services
Explore our complete web development solutions:
From Our Blog
Ready to Connect Your Systems?
Free consultation, detailed proposal within 24 hours, no obligation.