API Development & Integration That Connects Your Systems Reliably
We build clean APIs for your own products and connect third-party systems, such as ERP, CRM, payments and shipping, so data moves without manual re-entry.
Most businesses run on five or six tools that do not talk to each other. Orders sit in one place, stock in another, customers in a CRM and invoices in Tally. Staff fill the gaps by copying data between screens, which is slow and produces errors that only show up at month end.
NioDelta builds the connecting layer. That can be a REST or GraphQL API for your own app, a set of webhooks, or a connector between systems you already pay for. We care about what happens when things fail, because every integration fails sometimes. Every project ends with logs and a short runbook, so your team can understand what happened.
Integration problems that cost real money
Copy-paste between systems
Someone exports a sheet from the store and imports it into the ERP every evening. When they are on leave, shipping stops. The work is a symptom, and a small sync job removes it.
Integrations that fail silently
An order sync breaks after a vendor changes a field, and no one notices for a week. Without logs, alerts and retries, you learn about the failure from an angry customer.
Webhooks that arrive twice or not at all
Payment and courier providers send events more than once, or out of order. Code that assumes one clean event per action can double-ship an order or mark a paid invoice unpaid.
An API that grew without a plan
Endpoints added one by one, with no versioning or docs, break your mobile app and partners whenever you change anything. Cleaning this up later costs more than designing it first.
API development and third-party integration services
REST and GraphQL API design
We design resources, authentication, pagination and error formats before coding. You get an OpenAPI document that your mobile team and partners can read.
ERP and accounting integrations
Syncing items, parties, orders and invoices with Tally, Busy, Zoho Books or SAP-based systems, using the interface each one actually offers, whether API, connector or scheduled files.
CRM and marketing tool links
Leads from forms, WhatsApp and ads flow into Zoho, HubSpot or a custom CRM with the source tagged. Status changes can flow back to trigger messages.
Payment and shipping connectors
Razorpay, Cashfree and PayU for collection, and Shiprocket, Delhivery and other courier APIs for rates, labels and tracking, with status updates mapped to your order stages.
Webhook handling done safely
Signature checks, idempotency keys, queues and retry rules so duplicate or late events do not corrupt your data. Failed events are stored for review, not dropped.
Monitoring and documentation
Request logs, alerts on failure rates and a short runbook that tells your team what to check first. Integrations without this are the ones that cause late-night calls.
How an integration project runs
Discover
We list the systems, the data that must move, how often and in which direction. We also check API access, rate limits and plan restrictions with each vendor.
Define
We agree the field mapping, the source of truth for each record and the behaviour on conflict or failure. This is written down and signed off.
Design
We design the endpoints or sync jobs, the queue and the error handling. For client-facing APIs we publish the OpenAPI spec for review first.
Build
We build against sandbox accounts, replay recorded events and test the failure cases on purpose. Real data is tested on a small slice before the full run.
Ship & extend
We go live with monitoring on, then watch the first week closely. One month of support is included, and new connectors can be added as separate small scopes.
What it costs
Cost depends on how many systems are connected and how well each one documents its interface. Small point-to-point syncs are cheap, while a custom platform API sits in our web app range from ₹1,50,000.
- Number of systems and endpoints
- Quality of the third-party API
- Real-time versus scheduled sync
- Volume and retry requirements
- Documentation and monitoring needs
All prices exclude 18% GST. See also website costs and app costs.
Related work
Questions we get asked
What is the difference between an API and an integration?
An API is the interface a system offers so others can talk to it. An integration is the work of connecting two systems through their APIs. We build both: APIs for your own software, and integrations between tools you already use.
Can you integrate with Tally?
Yes, in most setups. Tally has no modern cloud API in older versions, so we use its XML interface or a connector utility on the machine that runs it. We confirm your version and network setup before committing to an approach.
REST or GraphQL, which should we choose?
REST is simpler and fits most business systems and partner access. GraphQL helps when many different screens need flexible slices of the same data, such as a mobile app with varied views. We choose based on your consumers, not fashion.
What if the vendor changes their API?
Vendors do change things. We version our side, log every call and alert on rising errors, so a break is caught within hours. Fixing vendor-driven changes can be covered under a maintenance plan after the first month.
Will you document the API?
Yes. Every API we build ships with an OpenAPI description and a Postman collection, plus a short note on authentication and error codes. A new developer on your side should be able to call it on day one.
Can you secure the API properly?
We use token-based authentication, rate limits, input validation and role checks on each endpoint. Webhook signatures are verified, and secrets stay in environment storage, not in code. A separate security audit is possible if your client demands one.
Ready to scope it?
Tell us what you want to build. You get a fixed written quote after a free discovery call.