Connect Your Business Systems and Stop Entering the Same Data Twice
GullySystem builds secure APIs, middleware and data synchronisation for businesses running separate CRM, ERP, accounting, payment and messaging systems, so a record is entered once and reaches every system that needs it.
- Every field mapped and agreed before code is written
- Retries, failure alerts and reconciliation built in
- Your accounts, your credentials, your source code
We build connections for the systems Indian businesses actually run on: Tally and Zoho Books ledgers, marketplace and dealer portals, payment gateways and UPI collections, courier partners, WhatsApp Business, and on-premise software that was installed years before the rest of your stack and has no API at all. Some of that work is a first connection between two systems. Some of it is repairing a connector built earlier that now drops records without telling anyone.
Is Your Team Doing the Same Work Twice Because Your Systems Don’t Talk?
Two Screens Open, Copying From One to the Other
Someone spends part of every day with the portal on one side and the billing screen on the other, copying customer name, item code and quantity across. The typing is the small cost. The real one is the gap: the second system runs hours behind the first, so the same stock gets promised twice and dispatch works from a figure that has already moved.
A Change Made in One Place Never Reaches the Other
A customer updates a delivery address or GST number in the portal, or a rate is revised in the ERP, and the second system quietly keeps the old value. The invoice goes out wrong, and the fix becomes a credit note and an apologetic phone call weeks later.
A Sync That Failed and Told Nobody
The connection breaks on a Friday evening. There is no alert, no retry and no log, so it is discovered on Monday when a customer asks why their order status never moved.
Payments Reconciled by Hand
Gateway settlements, UPI credits and bank statements are matched to invoices manually. Receipts get posted days late, and customers who have already paid still receive reminder messages.
Old Software That Refuses to Share
Your master item list, pricing or customer history sits inside an on-premise application with no modern interface. Staff work around it with CSV exports that are stale the moment they are taken.
Head Office Cannot Reach the Branch Systems
Each location runs its own copy of the billing or accounting software on a machine in that office. A revised price list travels by WhatsApp and is typed in again at every counter, so two branches quote different rates to the same dealer, and a customer put on credit hold at head office is still served at the third branch.
Enquiries Landing Where No System Sees Them
Website forms go to a shared inbox, WhatsApp enquiries sit on one phone, and listing-portal leads stay in a vendor panel. Nothing reaches the CRM, so follow-up depends on who remembers.
None of this needs a brand-new system. It needs the systems you already pay for to exchange the same record, in the same format, at the right time — and to raise a hand when they cannot.
Integration Built Around the Systems You Already Run
We connect your existing software rather than replacing it. We read your live data, agree what each field means in both systems, and build the connector, middleware or API that moves records between them with retries, logs and reconciliation you can check yourself.
One Agreed Record Format
Before any code, we map field to field: which system is the master for price, which for stock, what a blank value means, and what happens when the two disagree.
Delivery You Can Rely On
Network drops, expired tokens and vendor downtime are expected. Messages are retried, duplicates are blocked, and anything that still fails lands in a queue with an alert to a named person.
Provable, Not Just Working
Every message is logged with its source, destination and result, and a daily reconciliation compares counts on both sides so you can prove what moved and what did not.
What Changes Once Your Systems Talk
Focus on business value before discussing technology. Here is what your team accomplishes in week one.
One Entry, Used Everywhere
An order, lead or receipt is captured a single time and flows to billing, accounts and dispatch without anyone retyping it.
A Change Made Once Lands Everywhere
An address correction, a rate revision, an order status or a payment updates in one system and the connected systems carry the same value within the window agreed for that record, so nobody acts on a stale copy.
Failures That Announce Themselves
When a connection breaks or a vendor changes their API, a named person is notified with the affected record and the reason, instead of the problem waiting until a customer reports it.
Temporary Outages Handled Quietly
A gateway or portal being briefly unavailable no longer costs you a lost record, because pending messages are held and retried automatically.
Working Software Stays
Systems your team already knows keep running. We add the connection instead of forcing a migration you did not ask for.
Every Message Has a Record
Take any invoice, payment or status update and you can find the exact message that created it, with its source, time and response — which is what settles an argument with a courier, a gateway or a dealer.
What API and System Integration Includes
Everything required from operational discovery to production deployment and long-term maintenance.
Integration Audit and Data Mapping
We examine both systems, their live data and their existing interfaces, then document the records, fields, direction of flow and ownership rules that the integration must respect.
Custom API Design and Development
REST and webhook APIs built for your own applications, with authentication, versioning, rate limits, error codes and written documentation your other vendors can work against.
ERP and Accounting Integration
Two-way connections with Tally Prime, Zoho Books, Odoo and custom ERPs for masters, vouchers, stock movements and outstanding balances, respecting your ledger and voucher structure.
CRM and Sales System Integration
Lead capture from your website, WhatsApp and listing portals into Zoho CRM, Salesforce, HubSpot or your own CRM, with duplicate checks, owner assignment and status write-back.
Payment Gateway and Reconciliation
Razorpay, Cashfree, PayU and UPI collections wired to your invoices, with settlement files parsed, receipts posted and unmatched credits flagged for the accounts team.
WhatsApp, Email and SMS Integration
WhatsApp Business API, transactional email and SMS connected to your business events, with delivery and read status written back onto the order or ticket record.
E-commerce, Marketplace and Logistics
Storefront and marketplace orders pulled into your system, and courier partners connected for waybill generation, pickup requests and tracking updates that flow back to the customer.
Middleware, Webhooks and API Gateways
A queued middleware layer that receives events, transforms formats, throttles calls and holds failures, so neither system is exposed directly to the other’s downtime.
Legacy and On-Premise Integration
Older applications reached through database views, ODBC, scheduled file exchange over SFTP or a secure agent, so data leaves the system without disturbing the software your staff still use.
Multi-Location Data Consolidation
Branch, plant or campus systems feeding a single consolidated store on a real-time or scheduled basis, with location tagging so figures can be split back apart when needed.
Workspace and Document Integration
Google Workspace and Microsoft 365 connections for calendars, shared drives and mail, plus Google Maps and e-signature services where your process depends on them.
Monitoring, Alerting and Support
Dashboards for sync health, alerts for failures and credential expiry, and a support arrangement for the day a vendor changes their API without much notice.
Where Integration Changes the Working Day
Real-world business processes we configure and automate.
Distributor: Marketplace and Portal Orders into Accounts
A distributor sells through two marketplaces, a dealer portal and phone orders, and a back-office team retypes every order into billing and then into Tally. Integration pulls orders as they are placed, creates the sales entry against the correct ledger and stock item, and pushes the invoice number back to the channel, so dispatch documents and books agree without a second entry.
Clinic Network: Bookings Reaching the Billing System
A multi-centre clinic takes bookings on the website and by phone, but the patient is registered again at the counter and the confirmation message is sent by hand from a separate panel. Integration carries the booking, patient reference and doctor into the billing system as the slot is confirmed, triggers the confirmation on WhatsApp and writes the delivery result back onto the appointment, so the counter is not re-registering patients and the front desk can see which confirmations never landed.
Manufacturer: Field Service App to ERP
Service engineers close jobs in a mobile app while the ERP is updated later from paper job cards, delaying invoicing and spare-part consumption. Integration posts job completion, parts used and warranty status to the ERP as each visit closes, so billing runs the same day and stock reflects what has actually left the van.
Professional Firm: Every Enquiry into One CRM
An advisory firm receives enquiries through the website, WhatsApp and a listing portal, and each channel is checked by a different person. Integration routes all three into one CRM with duplicate detection and automatic owner assignment, so every enquiry has a name against it and follow-up is measurable instead of anecdotal.
Logistics Operator: Payments Matched to Invoices
A transport operator collects through a gateway, UPI and bank transfer, and reconciliation happens weekly against a spreadsheet. Integration marks invoices paid as confirmations arrive, holds unmatched credits in a review list for the accounts team, and stops reminder messages to customers who have already paid.
Retail Chain: One Price List Across Every Counter
A retail chain runs the same billing software separately at each showroom, so a revised rate or a new item is typed in again at every counter and the day’s sales reach head office as an emailed backup file. Integration pushes the approved item, rate and offer master out to each branch installation overnight and pulls the day’s bills back into central stock and accounts, so a customer is quoted the same price wherever they walk in and nobody at head office is waiting for a branch to send anything.
Is This Service Right for Your Business?
We partner with established businesses that have outgrown manual processes and want reliable systems.
Businesses Running Tally Alongside Everything Else
Companies where operations happen in a portal, an app or a CRM, but accounting lives in Tally or Zoho Books and someone bridges the gap by hand every evening.
Companies Selling Through More Than One Channel
Distributors, retailers and brands taking orders from a website, marketplaces, dealer portals and WhatsApp, where each channel is reconciled separately.
Multi-Branch and Multi-Plant Operations
Businesses running a local copy of the software at each location, who need the same masters at every counter and each branch’s transactions reaching head office without moving every site onto a new system at once.
Teams Whose Existing Integration Has Become Unreliable
Organisations with a connector built earlier that now drops records silently, cannot be monitored, or breaks whenever a vendor updates their API.
Companies Adding a New System to an Existing Stack
Businesses introducing a customer portal, field app, payment gateway or logistics partner that has to exchange data with software already in daily use.
When Integration Is Not the Right Answer
If you run a single system, or the volume is a handful of records a week, a scheduled export or an agreed shared sheet is cheaper and easier to maintain. If the underlying data is unreliable at source, integration only spreads the errors faster — fix the data entry first. We will tell you when that is the case rather than selling a connector you do not need.
Enterprise Capabilities in Plain Business Terms
Field-Level Data Mapping
A written map of every field, its format, its default and its meaning in both systems, signed off before build.
Master System Rules
Clear ownership for each data element, so a conflict has a decided outcome instead of the last write winning by accident.
Real-Time and Scheduled Sync
Event-driven flows for urgent records and batch windows for bulk data, chosen per record type rather than for the whole project.
Automatic Retries
Failed calls retried on a spaced-out schedule so short outages and rate limits recover without anyone noticing.
Duplicate Protection
Unique reference keys on every message so a retry or a replayed webhook cannot create a second invoice or a second lead.
Failed-Message Queue
Anything that cannot be delivered is held with its payload and error, ready to be corrected and reprocessed instead of lost.
Reconciliation Reports
Daily counts and value totals compared across both systems, with the differences listed rather than summarised.
Failure Alerts to People
Notifications to email, WhatsApp or a dashboard when a sync stops, a token expires or an error threshold is crossed.
Complete Message Logs
Searchable history of what was sent, when, by which process and with what response, kept for the retention period you specify.
Secure Credential Handling
API keys and tokens stored encrypted outside the code, scoped to the minimum permissions, and rotatable without a redeployment.
Rate Limit and Quota Handling
Call pacing and queuing that respect each vendor’s published limits so your account is not throttled or suspended.
Staging Environment Testing
Integrations proved against sandbox or test accounts with your real record shapes before anything touches live data.
Our Structured 6-Step Delivery Process
A transparent path from your first conversation to a reliable production release.
Discovery and System Audit
We sit with the people who currently move the data and list every system involved, what it holds and where the double entry happens. From you we need read access or sample exports from both sides, and the name of one person per system who can answer questions.
Integration Blueprint and Field Mapping
We produce the mapping document: records in scope, direction of flow, field-by-field translation, master rules, sync frequency and what should happen on conflict or failure. Nothing is built until you sign this off, because it is where most integration disputes are avoided.
Access, Authentication and Environment Setup
We define how each system will be reached and with what permissions. You raise API credentials in your own name with the vendors, provide sandbox or test accounts where they exist, and approve any network access needed for on-premise systems.
Connector and Middleware Build
We build the APIs, transformation logic, queues and scheduling, with retries, duplicate protection, logging and alerting included in the same work rather than added later. Progress is shown against the mapping document so you can see which flows are complete.
Testing, Reconciliation and Go-Live
We run the integration on test data, then in parallel with your current manual method, and reconcile both sides until the numbers match. You nominate the users who confirm the results, and we agree an acceptance point before switching the manual process off.
Monitoring, Handover and Support
We hand over the source code, mapping sheet, API documentation and runbook, train the person who will watch the sync dashboard, and continue on a support arrangement that covers vendor API changes, credential renewals and new flows.
What You Receive Upon Project Completion
Everything required to run, maintain, and expand your software without vendor lock-in.
Connects With the Systems You Already Rely On
We build bridges between your software so you don't have to replace functional existing tools.
Accounting and ERP
- Tally Prime / ERP 9
- Zoho Books
- Odoo
- QuickBooks
- Custom and legacy ERPs
CRM and Sales
- Zoho CRM
- Salesforce
- HubSpot
- Custom CRM databases
Payments and Collections
- Razorpay
- Cashfree
- PayU
- UPI collections
- Bank statement and settlement files
Messaging and Communication
- WhatsApp Business API
- Transactional SMS providers
- Transactional email services
Commerce and Logistics
- Shopify
- WooCommerce
- Marketplace seller panels
- Courier and shipping APIs
Workspace and Utilities
- Google Workspace
- Microsoft 365
- Google Maps
- E-signature services
- SFTP and file exchange
Selected for Reliability, Speed, and Longevity
Technology chosen to match your operational scale and long-term maintainability.
APIs and Services
Integration and Messaging
Data and Storage
Deployment and Monitoring
Why Business Owners Choose GullySystem
We Read Your Data Before We Quote
Sample records tell us more than a requirement list. Most integration surprises are hiding in inconsistent codes, duplicate customers and free-text fields, and we would rather find them early.
Failure Handling Is Part of the Build
Retries, duplicate keys, dead-letter queues and alerts are written alongside the happy path, not proposed as an upgrade after the first weekend the sync stops.
No Rip and Replace
If your accounting, billing or branch software works, it stays. We connect around it, and we say so plainly when a system genuinely cannot support what you want.
Written Contracts Between Systems
You receive the mapping sheet and API documentation, so another developer or vendor can work with the integration without reverse-engineering it.
Credentials Stay in Your Name
Gateway, WhatsApp, marketplace and cloud accounts are created under your business, with our access scoped and revocable. You are never dependent on us to keep the keys.
We Stay for the API Changes
Third-party APIs deprecate endpoints and rotate credentials on their own schedule. Our support arrangements exist because integrations need attention after go-live, not just at it.
Flexible Engagement Options
Choose an engagement model that matches your operational scope, budget, and timeline.
Fixed-Scope Integration
For a clearly bounded requirement such as orders into accounts or leads into CRM, priced against an agreed mapping document and acceptance criteria.
Phased Connector Rollout
Start with the single connection costing you the most manual hours, run it in production, then add the next flow once your team trusts the first.
Integration Audit and Repair
We review an existing integration, document what it actually does, and add the logging, retries and alerting it lacks before deciding whether to rebuild any part of it.
Managed Integration Support
For businesses running several live connections: monitoring, credential renewals, vendor API updates and new flows handled under a continuing arrangement.
Frequently Asked Questions
Straightforward answers to the questions owners ask before getting started.
Is integration only worth it for large companies?
No. The test is volume and pain, not company size. If your team retypes the same records every day, if two systems keep disagreeing, or if a missed update reaches a customer, integration usually pays for itself. If you have one system and a handful of records a week, a scheduled export is the cheaper answer and we will say so.
Do both systems need to have an API?
No. An API is the cleanest route, but it is not the only one. Where a system has no API we work with database views or an ODBC connection, scheduled file exchange over SFTP, its own import and export formats, or a small agent installed alongside it. During discovery we confirm which route each system supports before committing to a design.
Can you integrate old on-premise or legacy software?
Yes, in most cases. Legacy applications usually expose data through their database, a reporting view, or scheduled exports, and that is enough to build a reliable one-way or two-way flow. What we need is read access, permission from whoever supports that software, and clarity on which records may be written back. Where the vendor blocks all access, we tell you rather than working around it in ways that could break your licence or your data.
Is real-time synchronisation possible, or does it have to run on a schedule?
Both are possible, and the right choice differs by record type. Payments, order status and enquiries are usually event-driven so they move within seconds. Master data such as item lists, price lists and ledger balances often works better in scheduled batches, which is gentler on vendor rate limits. We decide this record by record during mapping rather than applying one mode to everything.
What happens when a sync fails?
It is caught, retried and reported. Every message carries a unique reference so a retry cannot create a duplicate, failed calls are retried on a spaced-out schedule, and anything still failing is held in a queue with its data and error message. An alert goes to a named person, and the record can be corrected and reprocessed. Daily reconciliation counts on both sides tell you nothing was quietly dropped.
How do you protect our data while it moves between systems?
Data moves over encrypted connections only, with credentials stored outside the code and scoped to the minimum permissions each system needs. On-premise connections use a controlled route rather than opening your server to the internet. Access to logs is restricted, sensitive fields can be masked, and we sign a non-disclosure agreement before discovery starts.
What drives the cost of an integration project?
Cost follows the number of flows and the state of your data, not a per-system price. The main drivers are how many record types move and in which directions, whether each system has a usable API, how clean and consistent the existing data is, how much transformation is needed between the two formats, whether historical records must be brought across, and the level of monitoring and support you want afterwards. We give an itemised proposal after discovery, with each flow priced separately so you can defer some.
What decides how long the work takes?
Duration depends mostly on access and data quality rather than on writing the connector. The factors are how quickly credentials and sandbox accounts are issued by each vendor, how consistent your existing records are, how many exceptions the mapping uncovers, whether a third-party vendor must make changes on their side, and how long you want to run the integration in parallel with the manual process before switching over. Discovery gives you a schedule tied to those inputs.
Do we need to move historical data as well?
Usually not all of it. Most businesses only need open items to move across: unsettled invoices, active customers, live orders and current stock. Full history is worth migrating when you need reporting continuity or an audit trail in the destination system. Where history is required, we clean and de-duplicate it, run a trial load, reconcile totals against the source, and get your sign-off before the live load.
Do we own the source code, documentation and credentials?
Yes, all three. You receive the complete source code and repository access, the field mapping sheet, the API documentation and the runbook. All vendor accounts and API credentials are created in your business name, with our access scoped and revocable at any time. Nothing is licensed back to you and nothing depends on us remaining involved.
Will you train our team and support the integration after go-live?
Yes. We train the people who will use the sync dashboard and handle exceptions, in plain language, with a short written runbook covering what each alert means and what to do about it. After go-live we offer a support arrangement covering monitoring, failure investigation, credential renewals, vendor API changes and additional flows as your systems change.
What do you need from us to get started?
Four things. A named contact for each system who can answer questions about how it is used, read access or sample exports from both sides, permission to raise API credentials and sandbox accounts with your vendors, and one person from operations who can decide the business rules when the two systems disagree. That last one matters most, because integration decisions are business decisions before they are technical ones.
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Related Practices & Services
Business Process Automation
Once your systems exchange data, automate the approvals, alerts and follow-ups that run on top of it.
ERP and CRM Implementation
Implementation and configuration when the answer is a properly set-up ERP or CRM rather than another connector.
Data Engineering and Business Intelligence
Turn the consolidated data your integrations produce into reliable reporting and management dashboards.
Custom Software and Product Engineering
Build the portal, app or platform that sits at the centre of your connected systems.