Custom API Development & Integration Company

Professional API development and integration services for websites, mobile apps, software systems, SaaS platforms and automation workflows

Q: Can you build APIs for mobile apps?

Yes. Nexus Web & Software builds secure mobile app APIs for login, user accounts, dashboards, orders, bookings, payments, notifications, content, data synchronization and admin management.

Q: Can you integrate payment gateways?

Yes. Nexus Web & Software can integrate payment gateways for websites, web applications, eCommerce stores, SaaS platforms, booking systems, mobile apps and business software.

Nexus Web & Software builds secure APIs and reliable integrations that connect your websites, mobile apps, CRMs, ERPs, payment gateways, eCommerce stores, SaaS platforms, dashboards and business systems into one smoother digital workflow.

We develop REST APIs, webhooks, backend endpoints, mobile app APIs, payment integrations, CRM connections, ERP integrations, third-party platform integrations and automation-ready data flows with clear planning, testing and long-term support.

Request API Quote Free Consultation View REST APIs

REST API Development
Payment Gateway Integration
CRM & ERP Integrations
Mobile App APIs
Webhooks & Automation

$250+Single API Integration

$1,200+REST API Development

SecureAuth & Data Flow

SupportMaintenance Available

Connected Digital Systems

Connect your business tools, websites, mobile apps and software platforms with secure API development

Modern businesses depend on multiple digital systems. Your website may need to connect with a CRM, your mobile app may need a secure backend, your online store may need payment and shipping APIs, or your business software may need data synchronization between departments.

Nexus Web & Software helps businesses reduce manual work, improve data flow and connect separate tools through professional API development and integration. We can build new REST APIs, connect third-party APIs, repair broken integrations, create webhook workflows, integrate payment gateways and develop backend services for web and mobile platforms.

Whether you need a simple API connection or a complex integration between several business systems, our approach focuses on clear requirements, secure authentication, structured endpoints, reliable testing, useful documentation and long-term support.

What API integration can help you do

Connect websites, apps, CRMs, ERPs and business software
Automate data transfer between tools and dashboards
Build secure APIs for mobile apps and SaaS platforms
Add payment gateways, checkout flows and transaction records
Create webhook-based notifications and automation workflows
Improve backend reliability, reporting and system communication

API Development Services

Complete API development and integration services for business platforms, apps and automation

Choose the API service that matches your website, software, mobile app, store or business workflow.

Custom REST API Development

Secure REST APIs for websites, software systems, mobile apps, SaaS platforms, customer portals, dashboards and workflow automation.

Request API quote

Third-Party API Integration

Connect external tools, CRMs, ERPs, payment gateways, shipping platforms, booking tools, analytics and automation services.

Plan integration

Payment Gateway Integration

Payment integrations for websites, eCommerce stores, booking systems, SaaS billing, invoices, subscriptions and mobile apps.

Explore payments

CRM API Integration

Connect forms, websites, apps, dashboards and lead systems with CRM platforms for better sales and customer management.

Explore CRM systems

ERP API Integration

Connect inventory, finance, HR, sales, purchasing, operations and reports between ERP systems and custom business platforms.

Explore ERP software

Mobile App API Development

APIs for Android, iOS and Flutter apps with authentication, user accounts, content, orders, bookings, payments and notifications.

Explore mobile apps

SaaS API Development

API architecture for SaaS products, subscriptions, dashboards, user accounts, billing systems, integrations and product workflows.

Explore SaaS

Webhook Development

Webhook workflows for real-time notifications, order updates, payment confirmations, lead routing, automation and data events.

Build webhooks

API Maintenance & Support

Bug fixes, endpoint updates, integration troubleshooting, webhook repairs, documentation updates, testing and long-term API support.

Explore API support

API Features

API features that make integrations secure, reliable and practical for real business workflows

We build APIs and integrations with structure, security, testing and maintainability in mind.

Secure Authentication

APIs must protect sensitive data and business systems. We plan authentication methods, protected endpoints, validation and access controls based on your project needs.

Token-based API authentication
Protected endpoint access
User and application permissions
Input validation and error handling
Secure data exchange planning

Structured Data Flow

Good integrations depend on clean data mapping. We define what data moves, when it moves, where it is stored and how systems stay synchronized.

Data mapping and transformation
Database synchronization logic
Import and export workflows
Record matching and updates
Logs and integration status tracking

Webhook Automation

Webhooks help systems react to events in real time, such as new orders, payment confirmations, lead submissions, appointment bookings or status updates.

Event-based triggers
Order and payment webhooks
Lead routing workflows
Notification automation
Webhook testing and troubleshooting

Documentation and Testing

APIs are easier to maintain when endpoints, fields, responses, errors and workflows are documented and tested before launch.

Endpoint documentation
Request and response examples
Error handling guidance
Sandbox and live testing support
Post-launch maintenance planning

Integration Solutions

API integration solutions for websites, apps, stores, software systems and business automation

We connect the tools and platforms your business depends on.

Payment Integrations

Connect checkout flows, invoices, subscriptions, bookings, mobile apps and eCommerce stores with payment gateways and transaction records.

Explore payment gateways

CRM Integrations

Send leads, customer records, enquiry forms, sales data and follow-up tasks into CRM systems for better customer management.

Explore CRM systems

eCommerce Integrations

Connect stores with payments, shipping tools, inventory systems, email marketing, analytics, order management and customer platforms.

Explore eCommerce

App Backend APIs

Power Android, iOS and Flutter apps with login, profiles, content, bookings, orders, payments, notifications and admin dashboards.

Explore mobile app APIs

Dashboard Integrations

Pull data into admin dashboards, reports, analytics pages, management screens and operational views from multiple sources.

Explore dashboards

Workflow Automation

Automate repetitive data entry, notifications, approvals, status updates, lead assignment, reporting and system-to-system actions.

Explore automation software

Why Choose API Integration

APIs help your digital systems communicate, reduce manual work and create smoother business operations

When systems are disconnected, teams waste time copying data, checking multiple dashboards and fixing avoidable errors. API integrations create a structured bridge between platforms so information can move automatically and your business can operate with better speed, visibility and control.

Why Choose Nexus

Automated Data Flow

Move information between websites, apps, CRMs, ERPs, stores and dashboards without repetitive manual entry.

Secure Connections

Use protected endpoints, authentication, validation and controlled access for sensitive business data.

Better Reporting

Pull data from different systems into dashboards and reports so decision-making becomes clearer.

Real-Time Events

Use webhooks for payment confirmations, order updates, booking alerts, lead notifications and system triggers.

Scalable Architecture

Build APIs that support future integrations, new modules, mobile apps, dashboards and digital platforms.

Long-Term Support

Maintain API connections with updates, troubleshooting, testing, endpoint changes and integration improvements.

API Development Process

Our API development process keeps integrations secure, documented and reliable from planning to launch

We define systems, data, endpoints, authentication, testing and maintenance before going live.

01
Integration Discovery

We understand the systems you want to connect, business goals, user flows, data requirements, security concerns and expected outcomes.
02
Data Mapping and Workflow Planning

We define what data moves, which fields are required, how records match, when updates happen and how errors should be handled.
03
API Architecture and Security

We plan endpoints, authentication, permissions, request formats, response formats, rate limits, logs and security controls.
04
Development and Integration Setup

We build endpoints, connect third-party APIs, configure webhooks, create backend logic and develop required data workflows.
05
Testing and Validation

We test requests, responses, authentication, errors, edge cases, sandbox flows, webhook events and live environment readiness.
06
Documentation and Launch

We prepare endpoint notes, setup guidance, integration details, testing references and deployment support for your team.
07
Maintenance and Improvements

After launch, we can support endpoint updates, API version changes, broken integrations, webhook issues and new feature requests.

API Integration by Industry

API development for industries that need connected systems, automation and reliable data flow

We adapt API integrations around each industry’s platforms, operations, users and reporting needs.

eCommerce API Integrations

Connect payments, shipping, inventory, product catalogs, orders, customer accounts, email tools and analytics platforms.

View eCommerce

Healthcare API Integrations

Connect appointment systems, portals, forms, dashboards, notifications and healthcare workflow tools with secure data planning.

View healthcare

Real Estate API Integrations

Connect property listings, lead forms, CRM systems, agent dashboards, enquiry tools and customer communication workflows.

View real estate

Education API Integrations

Connect student portals, enrollment systems, learning platforms, content tools, notifications and admin dashboards.

View education

Logistics API Integrations

Connect shipment tracking, booking systems, driver apps, customer portals, delivery updates and operational reports.

View logistics

Manufacturing API Integrations

Connect inventory systems, production dashboards, supplier portals, ERP tools, purchase records and reporting workflows.

View manufacturing

Legal API Integrations

Connect client portals, case enquiry forms, document workflows, appointment tools and law firm CRM systems.

View legal services

Startup API Development

Build MVP APIs, SaaS backends, mobile app APIs, subscription workflows, product integrations and scalable API roadmaps.

View startups

API Technology Stack

Technologies we use to build secure APIs, backend services and system integrations

We choose the right API stack based on your platform, database, hosting, authentication, integrations and scalability needs.

REST APIs PHP Laravel Node.js JavaScript MySQL PostgreSQL AWS Google Cloud Payments Mobile APIs API Support

API Development Pricing

Flexible API development and integration pricing for websites, apps, payments, CRMs and business platforms

These are starting prices. Final pricing depends on endpoint count, authentication, data mapping, platforms, testing, documentation and support requirements.

Simple

Single API Integration

$250+

Best for connecting one third-party API, form, payment tool, CRM field, webhook or basic data transfer workflow.

One API connection
Basic authentication setup
Data field mapping
Testing support
Setup notes

Request Integration Quote

Custom

REST API Development

$1,200+

Best for websites, dashboards, mobile apps, SaaS products and software systems that need custom backend endpoints.

Custom endpoints
Authentication planning
Request and response structure
Error handling
Documentation basics

Request API Quote

Business

System Integration

$2,500+

Best for CRM, ERP, eCommerce, SaaS, booking, inventory and multi-platform data synchronization projects.

Multiple systems connected
Advanced data mapping
Webhooks and automation
Testing and troubleshooting
Launch support

Request System Quote

Support

API Maintenance

$200/mo+

Best for existing APIs and integrations that need updates, endpoint fixes, webhook support and ongoing technical maintenance.

Bug fixes and troubleshooting
Endpoint updates
Webhook support
API version changes
Monthly support options

Get API Support

Related Services

API development connects with software, mobile apps, web applications, eCommerce and payment systems

Build a stronger digital platform by combining APIs with the right related development services.

Software Development

Build custom software systems, dashboards, CRMs, ERPs and workflows that connect through secure APIs and integrations.

Explore software

Web Application Development

Create browser-based apps, portals, admin dashboards and SaaS platforms powered by API-ready backend services.

Explore web apps

Mobile App Development

Build Android, iOS and Flutter apps that connect with secure APIs, databases, dashboards, payments and notifications.

Explore mobile apps

Payment Gateway Integration

Connect payment gateways with websites, stores, booking systems, SaaS platforms, mobile apps and custom software.

Explore payments

API Development FAQs

Helpful answers about API development, integrations, pricing, webhooks and support

These FAQs explain API development, payment integrations, mobile APIs, CRM connections, ERP workflows and maintenance.

What API development and integration services do you provide?

Nexus Web & Software provides REST API development, third-party API integration, payment gateway integration, CRM API integration, ERP API integration, mobile app APIs, SaaS APIs, webhook development, backend integrations and workflow automation.

How much does API integration cost?

A single API integration can start from $250. Custom REST API development can start from $1,200, while complex system integrations can start from $2,500 depending on endpoints, data mapping, authentication, testing, documentation and support needs.

Can you build APIs for mobile apps?

Yes. We build APIs for Android, iOS and Flutter apps, including login, user accounts, dashboards, bookings, orders, payments, notifications, content, data synchronization and admin control.

Can you integrate payment gateways?

Yes. We can integrate payment gateways for websites, eCommerce stores, SaaS platforms, booking systems, mobile apps, custom software, subscriptions and invoices.

Can you connect my CRM or ERP system?

Yes. We can connect CRM and ERP systems with websites, forms, dashboards, mobile apps, sales tools, inventory workflows, customer portals and business software.

Do you provide API support after launch?

Yes. API support can include bug fixes, endpoint updates, authentication changes, webhook troubleshooting, API version updates, documentation changes, testing and long-term integration maintenance.

Ready to Connect Your Systems?

Let’s build secure APIs and integrations that connect your websites, apps, payments, CRMs, ERPs and business tools

Share the platforms you want to connect, data flow requirements, current API documentation, user workflows, security needs and timeline. Nexus Web & Software can help you plan the right API development and integration roadmap.

Request API Quote Free Consultation

API Development Sitemap

Explore API services, integrations, technologies and related development pages

Use these links to continue planning your API development and integration project.