Make your tools talk to each other

API integration connects your software tools so data moves between them on its own. An API is the door a tool offers to other software: a way to read an order, create an invoice or update stock without a person typing it in.

Most growing businesses run on a handful of good tools that don’t talk to each other: an online store, a marketplace or two, a payment gateway, Tally, a courier, WhatsApp and a CRM. Each works well alone. The gaps between them are filled by people copying, checking and chasing, and that is where errors, delays and late nights come from.

Integration closes those gaps. Your tools stay; the retyping goes.

Use a ready-made connector when one exists and fits; build when it doesn’t. Many tools offer their own plug-ins, and platforms such as Zapier or Make join popular apps without code. For simple, low-volume flows they are a good choice, and we will say so.

A custom integration pays off when volumes are high, when the rules are particular to your business, when a failure must never pass unnoticed, or when the tools are Indian or in-house software those platforms don’t cover. It also pays off when several flows share the same records: one hub with one set of IDs, logs and alerts is easier to trust than a dozen separate automations nobody owns.

Often the answer is a mix: ready-made connectors where they are solid, and custom work for the flows that matter most.

The best first flow is the one your team copies most often, with the most mistakes. Usually it is one of these:

• orders into accounts: every order from the store or billing system becomes an invoice in Tally or your accounting software;
• stock across channels: every sale updates stock wherever the item is listed;
• payments to invoices: gateway payments, refunds and settlements matched to the right orders;
• shipping: courier booking, labels and tracking updates flowing back into orders and out to customers;
• leads into the CRM: enquiries from forms, ads, IndiaMART and WhatsApp landing with their source.

A Mumbai skincare brand we built for shows several at once: Shopify webhooks keep the store’s own database in step with orders and subscriptions, Razorpay handles payments and UPI AutoPay mandates, a shipping aggregator allocates couriers, and the WhatsApp Business API carries confirmations and delivery updates.

A supermarket chain we built for in Cork shows another kind. A till integration layer connects its loyalty system to the point-of-sale system already in every store, so points and offers apply at the till, and if a store’s network drops, the shops are queued and added when it returns.

We need to see the copying, access to the tools, and one person who decides which tool is right when two disagree.

Seeing the copying means sitting with the people who do it: which screens they move between, what they check, and what goes wrong. Access means an admin or developer login for each tool, so we can create a dedicated key for the integration, plus a test or sandbox account where the tool offers one. The person who decides settles questions such as whether the store or Tally holds the true customer name.

We also need to know your busy moments: sale days, month end, the first of the month when invoices go out. The connections are tested at the volume they will really meet.

Most integration problems are data problems, so we map before we build. For each flow we agree which tool is the source of truth for each field, how records are matched across tools, and what happens to edge cases: a part refund, a cancelled order after dispatch, a customer with two phone numbers, a product sold in packs on one channel and singly on another.

Every record gets one ID that follows it across tools, so an order in the store, its invoice in Tally, its payment in the gateway and its shipment with the courier can always be found from one another. Units, tax codes, ledgers and currencies are mapped once and tested on your real records.

An integration that works on a quiet Tuesday is easy. The test is sale day, month end and the night a tool goes down. So every connection we build has the same safeguards.

Events arrive through webhooks where tools offer them, and through scheduled checks where they don’t, so nothing is missed if a webhook is lost. They pass through a queue that absorbs bursts. Each sync is checked before it is sent, retried with growing gaps if the other tool is busy or down, and stopped with an alert to a person if it still can’t get through. Each record carries its own ID, so a retry never creates a second order, invoice or payment.

Every attempt is logged with what moved and what came back. When a record is fixed, it can be replayed with one action instead of being typed in again.

Many integrations in India meet the same systems, and each has its habits. Tally usually runs on a computer in the office, so we connect directly or through a small connector there. GST e-invoices and e-way bills are generated through authorised GST API providers, with the IRN and QR code returned onto the invoice. A brass components manufacturer we built for in Jamnagar generates both at dispatch and sends the invoice to Tally without retyping.

UPI and card payments arrive through gateways such as Razorpay, with settlements and refunds to reconcile. Couriers and shipping aggregators each report tracking and failed deliveries in their own way, and marketplaces and IndiaMART have their own order and lead formats. Our portfolio already includes Tally, GST e-invoicing, Razorpay, shipping aggregators and WhatsApp, which shortens the work.

Some software has no API, or one that doesn’t do what you need. That doesn’t always rule it out.

Older or in-house systems can often be reached through their database with read access, scheduled file exports, or the emails they send. Hardware can need a gateway: a transport company we built for in Coimbatore had GPS devices from different suppliers, each with its own data format, and a device gateway now reads them all onto one live map. We tell you which route is reliable enough before we build, and what it means for speed and upkeep.

Every connection gets its own key with the narrowest permissions that do the job, never a person’s login, so it can be limited, watched and switched off on its own. Keys live in a secrets store, not in code or spreadsheets. Access is reviewed when people or partners change, and any key can be withdrawn without touching the others.

Only the fields a tool needs are sent, data is encrypted in transit, and sensitive fields such as phone numbers, bank details and ID numbers are masked in the logs.

Before we build, we agree what success looks like: how many records the flow moves without a person, how fast they arrive, how many need attention, and how many hours of copying stop.

After launch, a short report shows those numbers each month, along with every failure and what caused it. Alerts go to a named person for each flow, by email, Slack or WhatsApp, with the record and the error attached, so every fix starts from the facts. Tools change their APIs, retire old versions and add new limits, so we watch for those changes and update connections before they break. When one flow is settled, the next is usually quicker, because it plugs into the same hub, IDs and logs.