REST & GraphQL API Development
Design and build scalable, well-documented REST and GraphQL APIs following OpenAPI standards. Rate limiting, versioning, authentication, and caching included.
80+ Integrations Built
API Integration Services
That Connect Any System
Fidusia delivers expert API integration services — REST, GraphQL, webhooks, payment gateways, CRM, ERP, and custom iPaaS. We connect your SaaS to the tools your customers already use.
Integration Services
Every API Integration Service
Your Business Needs
From simple third-party integrations to complex enterprise API architectures — Fidusia handles it all.
Payment Gateway Integration
Stripe, Razorpay, PayPal, Braintree, Square, and regional payment gateways. Subscription billing, one-time payments, refunds, and reconciliation automation.
CRM & Marketing Integrations
Salesforce, HubSpot, Pipedrive, ActiveCampaign, Mailchimp integrations. Bi-directional data sync, webhook automation, and customer lifecycle management.
ERP & Enterprise System Integration
SAP, Oracle ERP, Microsoft Dynamics, NetSuite integration via REST bridges, Kafka event streaming, and secure VPN tunnels for on-premise systems.
Communication & Notification APIs
Twilio SMS/voice, SendGrid email, WhatsApp Business API, Firebase push notifications, and multi-channel notification orchestration systems.
AI & Third-Party API Integration
OpenAI GPT, Claude, Google AI, Algolia search, Google Maps, Plaid banking, DocuSign e-signature, and any third-party API your product requires.
Production-Ready API Integrations
Every integration we build follows best practices: typed, tested, documented, and retry-safe.
stripe-integration.ts
// Stripe subscription with webhook validation
const stripe = new Stripe(process.env.STRIPE_KEY);
export async function createSubscription(
customerId: string,
priceId: string
) {
return await stripe.subscriptions.create({
customer: customerId,
items: [{ price: priceId }],
payment_behavior: 'default_incomplete',
expand: ['latest_invoice.payment_intent']
});
}
const stripe = new Stripe(process.env.STRIPE_KEY);
export async function createSubscription(
customerId: string,
priceId: string
) {
return await stripe.subscriptions.create({
customer: customerId,
items: [{ price: priceId }],
payment_behavior: 'default_incomplete',
expand: ['latest_invoice.payment_intent']
});
}
webhook-handler.ts
// Verified webhook event processing
export async function handleWebhook(
req: Request
) {
const sig = req.headers['stripe-signature'];
const event = stripe.webhooks.constructEvent(
req.body, sig, WEBHOOK_SECRET
);
switch (event.type) {
case 'invoice.paid':
await activateSubscription(event);
break;
}
}
export async function handleWebhook(
req: Request
) {
const sig = req.headers['stripe-signature'];
const event = stripe.webhooks.constructEvent(
req.body, sig, WEBHOOK_SECRET
);
switch (event.type) {
case 'invoice.paid':
await activateSubscription(event);
break;
}
}
FAQ
API Integration FAQs
What API integration services does Fidusia offer?▾
Fidusia offers REST API development, GraphQL API design, webhook integrations, payment gateway integrations (Stripe, Razorpay, PayPal), CRM integrations (Salesforce, HubSpot), ERP integrations (SAP, Oracle), communication APIs (Twilio, SendGrid), and custom iPaaS workflow automation with 80+ pre-built connectors.
How long does an API integration project take?▾
Simple third-party API integrations typically take 1–2 weeks. Complex enterprise integrations with multiple systems, data transformation, and error handling take 4–8 weeks. Full custom API platforms with developer documentation and SDKs take 8–16 weeks.
Can Fidusia integrate with legacy and on-premise ERP systems?▾
Yes. Fidusia has deep experience integrating with legacy systems including SAP, Oracle ERP, Microsoft Dynamics, and custom on-premise databases via secure VPN tunnels, REST/SOAP bridges, message queues (RabbitMQ, Kafka), and event-driven integration patterns.
Does Fidusia build API documentation and developer portals?▾
Yes. We build comprehensive API documentation using OpenAPI/Swagger, interactive API explorers with authentication management, SDKs for JavaScript, Python, PHP, and Java, and complete developer portals with rate limit dashboards and webhook testing tools.