API Development & Integration · India
API integration services that stop your team copying data between systems.
We connect your website, apps, CRM, ERP, payment gateways and the tools you already pay for, and build custom APIs when off-the-shelf connectors don’t fit. From a single website API integration to a full system-to-system data flow, our in-house developers in Mumbai deliver secure, documented and tested integrations.
What is API integration?
API integration is the process of connecting two or more software systems through their application programming interfaces (APIs), so they can exchange data and trigger actions automatically. For example, a website form can create a lead in your CRM, an online order can update stock in your ERP, or a payment gateway can confirm a payment back to your store. Most modern integrations use REST API integration with JSON data; API development is building the APIs themselves when a system doesn’t already offer the endpoints you need.
What do ABC Designs’ API development services include?
ABC Designs is an API development company in India, based in Andheri East, Mumbai, and founded in 2012. We provide custom API development, third-party API integration, REST API development, cloud API integration, mobile and web app API integration, secure API development, and API testing and documentation. Our developers connect websites, web apps, mobile apps, SaaS tools, CRMs, ERPs, payment gateways and ecommerce platforms, working with REST, JSON and cloud-based APIs on Node.js and Laravel.
01 — Diagnosis
Signs your systems need API integration
Most businesses don’t think “we need an API”. They notice the symptoms below. Each one is time, money or accuracy leaking out of the business.
Data is copied by hand
You’ll notice: someone exports, pastes or re-types leads, orders or invoices every day.
How we fix it: Automated data flows between your systems.
Numbers don’t match
You’ll notice: stock, prices or order status differ between your website and back office.
How we fix it: Real-time or scheduled syncing with one source of truth.
Leads go missing
You’ll notice: website enquiries sit in an inbox and never reach the CRM or sales team.
How we fix it: CRM API integration with instant lead routing.
Integrations break silently
You’ll notice: a connector stopped working weeks ago and nobody knew.
How we fix it: Error handling, retries, logging and alerts.
Your app can’t reach your data
You’ll notice: a mobile or web app that can’t use data from your existing systems.
How we fix it: Custom APIs that expose the right data securely.
Security is unclear
You’ll notice: shared passwords, open endpoints or no idea who can access what.
How we fix it: Authentication, encryption, access control and rate limiting.
02 — What’s included
Our API integration and development services
Seven services, combined into one plan for your systems. On the first call we map what needs to connect and recommend the simplest reliable approach.
Custom API development
01Custom API development services for when your systems don’t offer the endpoints you need, built around your business logic.
- Endpoint and data model design
- Business rules and validation
- Versioning for future changes
You get: An API built for exactly what you need
Third-party API integration
02Third-party API integration services for payment gateways, CRMs, ERPs, shipping, analytics and marketing tools.
- Connector setup and data mapping
- Webhooks and event handling
- Error handling and retries
You get: Your tools working as one system
REST API development
03REST API development services for lightweight, scalable communication between your systems.
- RESTful endpoints with JSON
- Pagination, filtering and caching
- Standard HTTP status and error codes
You get: A clean, predictable API
Connect SaaS products, cloud applications and distributed systems.
- SaaS-to-SaaS integrations
- AWS-hosted integration services
- Scheduled and event-driven syncs
You get: Cloud tools that share data reliably
Secure connections between your apps and your back-end systems.
- App back ends and APIs
- User authentication
- Push notification and messaging APIs
You get: Apps that use your real data
Secure API development
06APIs protected with proper authentication, authorisation, encryption and access control.
- API keys, OAuth 2.0 or JWT
- HTTPS and input validation
- Rate limiting and access logs
You get: Data shared only with who should see it
API testing, optimisation & documentation
07Performance testing, tuning and developer-friendly documentation for every API.
- Functional and load testing
- Response time optimisation
- OpenAPI / Postman documentation
You get: APIs any developer can understand and maintain
03 — What we connect
Common API integrations we build
These are the integrations businesses ask for most. If your tool has an API, we can usually connect it.
| Integration | Example tools | What it automates |
|---|---|---|
| Payment gateway API integration | Razorpay, PayU, Cashfree, Stripe, PayPal | Payments, refunds, payment status and reconciliation |
| CRM API integration | Zoho CRM, HubSpot, Salesforce | Lead capture, lead routing, contact and deal updates |
| ERP & accounting | SAP, Tally, Zoho Books | Orders, invoices, stock and pricing sync |
| Shopify API integration | Shopify Admin API | Products, inventory and orders synced with ERPs, warehouses and marketplaces |
| Shipping & logistics | Shiprocket, Delhivery and courier APIs | Shipping rates, label creation and order tracking |
| Messaging & notifications | WhatsApp Business API, SMS and email gateways | Order updates, OTPs and lead alerts |
| Maps & location | Google Maps Platform | Store locators, distance and serviceability checks |
| Analytics & marketing | GA4, Meta Conversions API | Conversion and event tracking |
04 — Choosing an approach
Ready-made connector, custom API integration or custom API: which do you need?
We recommend the simplest option that will stay reliable as you grow.
| Ready-made connector / no-code | Custom API integration | Custom API development | |
|---|---|---|---|
| What it is | A plugin, app or tool like Zapier linking two systems | Code connecting existing APIs with your own logic | Building new APIs for systems that don’t have them |
| Best for | Simple, low-volume, standard flows | Specific data mapping, rules or volumes | Exposing your own data to apps, partners or other systems |
| Flexibility | Limited to what the connector supports | High | Complete |
| Running cost | Monthly subscription per task or user | Hosting and maintenance | Hosting and maintenance |
| Watch out for | Task limits, silent failures, data exposure | Changes to third-party APIs | Higher upfront effort |
05 — Our process
How we build and integrate APIs, step by step
Every API project follows the same six steps, so you always know what we’re working on and what we need from you.
-
Step 1 · Discover
Understand your processes
- Business processes and goals
- Current systems and data flows
- What should happen automatically
Deliverable: Integration requirements · We need from you: List of systems and owners
-
Step 2 · Analyse
Assess systems and APIs
- Available APIs and their limits
- Integration points
- Security and performance needs
Deliverable: Technical assessment and fixed quote · We need from you: API access and sandbox accounts
-
Step 3 · Strategise
Design the integration
- Architecture and endpoints
- Data formats and field mapping
- Authentication method
Deliverable: Integration design and data map · We need from you: Sign-off
-
Step 4 · Develop & integrate
Build and connect
- API development and connectors
- Error handling and retries
- Logging and alerts
Deliverable: Working integration in a test environment
-
Step 5 · Test & secure
Test end to end
- Functional and edge-case testing
- Load and performance tests
- Security checks
Deliverable: Test report and documentation
-
Step 6 · Deploy, monitor & improve
Go live and watch it
- Production deployment
- Monitoring and alerts
- Ongoing fixes as third-party APIs change
Deliverable: Live integration, code, credentials and docs
06 — Timelines
How long does API integration take?
A single standard integration usually takes 1–2 weeks; custom APIs and multi-system integrations take 3–8 weeks. Waiting for API access and sandbox accounts from third parties is often the biggest delay, so we request those first.
Single integration. e.g. website form to CRM, or payment gateway.
Multi-system integration. e.g. store, ERP and shipping in sync.
Custom API. New API for an app or partner access.
Typical ranges, not a guarantee. Your exact timeline is agreed in the scope.
07 — Built to last
What we check before an integration goes live
An integration that fails silently is worse than none. Here’s what we build in and test.
| What we check | Why it matters | Our standard |
|---|---|---|
| Security | APIs move sensitive business and customer data. | HTTPS, authentication, least-privilege access, secrets kept out of code |
| Error handling | Third-party APIs fail sometimes. | Retries, queues and clear error logs |
| Monitoring | Problems should be caught before customers notice. | Automated failure alerts and error logs |
| Performance | Slow APIs slow down your website and apps. | Response-time targets agreed per endpoint, then load-tested |
| Data accuracy | Wrong data spreads to every connected system. | Field mapping tests and validation |
| Documentation | Someone has to maintain it later. | Endpoint docs, data map and runbook |
08 — Our work
See the websites and apps we’ve connected
Most of the websites, stores and apps we build talk to other systems: CRMs, payment gateways, ERPs and shipping partners. Browse our live projects, then ask us on your first call how the integrations behind any of them were planned, built and monitored.
What you get at handover
- ✓ Source code and repositories
- ✓ API keys and credentials in your name
- ✓ Endpoint docs and data map
- ✓ A runbook for when things fail
09 — By business type
What we prioritise depends on how your business runs
Ecommerce & D2C
Ecommerce API integration keeps stock, orders and shipping in sync.
FOCUS · Payments, inventory, shipping, marketplaces
Manufacturers & distributors
Orders and pricing live in the ERP; customers order online.
FOCUS · ERP sync, B2B pricing, dealer portals
Service businesses
Leads come from many channels and must reach sales fast.
FOCUS · CRM integration, lead routing, WhatsApp
SaaS & startups
Your product needs to connect to the tools your customers use.
FOCUS · Public APIs, webhooks, documentation
Healthcare & education
Bookings, payments and records across several systems.
FOCUS · Booking APIs, payments, secure data
Mobile app owners
Your app is only as good as the back end behind it.
FOCUS · App APIs, auth, push notifications
10 — Choosing a partner
How to choose an API integration company
Integrations are invisible when they work and expensive when they don’t. Ask these six questions before you hire anyone.
Have they integrated your tools before?
Experience with the same CRM, ERP or gateway saves time and surprises.
How do they handle failures?
Ask about retries, logging and who gets alerted when something breaks.
How do they secure credentials?
API keys should never be hard-coded or shared over email.
Will you get documentation?
Docs and a data map mean any developer can maintain it later.
Will you own the code?
Code, repositories and credentials should be yours.
Who fixes it when an API changes?
Third-party APIs change. Check support terms and response times.
11 — Our standards
How we work: what we always do, and what we never do
We want you to know exactly what to expect before a single line of code is written.
We always
- Test in sandbox environments before touching live data
- Store API keys and secrets securely
- Document every endpoint and data mapping
- Hand over code, repositories and credentials
- Agree scope, price and dates in writing
We never
- Hard-code passwords or API keys
- Request more data access than an integration needs
- Store card data on your servers
- Launch without error handling and logging
- Add hidden charges after the quote
12 — Pricing
How much do API integration services cost?
API integration cost in India depends on the number of systems, the quality of their APIs, the volume of data, custom logic and security requirements. You’ll get a fixed, itemised quote after a short technical call.
Standard integration
Fixed quote · 1–2 weeks
One well-documented third-party API, such as a payment gateway or CRM.
- Setup and data mapping
- Error handling
- Testing
- Documentation
Multi-system integration
Fixed quote · 3–6 weeks
Two or more systems kept in sync, such as store, ERP and shipping.
- Everything in Standard
- Custom sync logic
- Queues and retries
- Monitoring and alerts
Custom API development
Quoted after scoping
New APIs for apps, partners or internal systems.
- API design and build
- Authentication and security
- Load testing
- Full developer docs
What changes the price: number of systems · API quality and limits · data volume · real-time vs scheduled sync · security and compliance needs · ongoing monitoring and support. Third-party API and subscription fees are separate.
13 — Tools & technologies
The technologies we use for APIs
Proven, well-supported tools, chosen for reliability and easy maintenance.
14 — FAQ
API integration services: frequently asked questions
Still unsure? Tell us which systems you want to connect and we’ll answer these for your setup.
What is API integration?
API integration connects two or more software systems through their APIs so they exchange data and trigger actions automatically, such as sending website leads to a CRM or syncing orders with an ERP.
What’s the difference between API development and API integration?
API development builds a new API for a system. API integration connects existing APIs so systems work together. Many projects need both.
How much does API integration cost in India?
It depends on the number of systems, the quality of their APIs, data volume and custom logic. A single standard integration costs less than a multi-system one, and custom API development is quoted after scoping. After a short technical call you’ll get a fixed, itemised quote before any work starts.
Do you offer custom API development services?
Yes. We design and build custom APIs around your business logic, with authentication, documentation and testing, for websites, apps, partners and internal systems.
Can you integrate payment gateways?
Yes. We handle payment gateway API integration for Razorpay, PayU, Cashfree, Stripe and PayPal, including payment confirmation, refunds and reconciliation, without storing card data on your servers.
Can you integrate my website with a CRM?
Yes. CRM API integration sends leads from your website, forms and ads straight to your CRM and routes them to the right person. We work with CRMs such as Zoho CRM, HubSpot and Salesforce.
Do you do Shopify API integration?
Yes. We use the Shopify API to connect stores with ERPs, warehouses, marketplaces and custom apps, syncing products, inventory and orders.
Are your APIs secure?
Yes. We use HTTPS, authentication (API keys, OAuth 2.0 or JWT), access control, input validation and rate limiting, and keep credentials out of code.
Will I get documentation?
Yes. Every API comes with developer-friendly documentation, a data map and handover notes.
Can you work with my existing systems?
Yes. We integrate with existing websites, apps, CRMs, ERPs and third-party platforms, as long as they offer an API or a supported data export.
Are you an API development company in India that works with overseas clients?
Yes. We’re based in Mumbai and work with businesses across India and abroad, with reviews over video calls and shared test environments.
Do you provide support after deployment?
Yes. Every integration includes 30 days of free support for bugs and small fixes, then optional monitoring, maintenance and updates when third-party APIs change. See maintenance and support.
15 — Glossary
API terms, explained simply
- API (application programming interface)
- A defined way for one piece of software to request data or actions from another.
- REST API
- The most common style of web API, using standard web requests and usually JSON data.
- Endpoint
- A specific address in an API that handles one type of request, such as “create order”.
- Webhook
- A message one system sends to another automatically when something happens, such as a payment succeeding.
- JSON
- A lightweight text format for sending structured data between systems.
- OAuth 2.0
- A secure standard for letting one system access another without sharing passwords.
- Rate limit
- A cap on how many requests an API accepts in a set time.
- Sandbox
- A test environment where integrations can be built without touching real data.