Developer API

Secure, Real-Time API Access for Busy Accounting Software

Standard Endpoints | Custom SQL Queries | 24/7 Data Availability

Unlock the full power of your financial data. The Whats91 API engine transforms on-premise Busy Accounting Software into a cloud-ready data source. Integrate your ledger, inventory, and outstanding data directly into your CRM, custom mobile apps, or enterprise dashboards.

REST API

JSON • HTML • PDF

99.99% Uptime

REST API Engine

99.99% Uptime • 0 requests today

Token Auth

Data Flow Architecture

Live

Busy ERP

On-premise data

API Server

Secure gateway

Transform

Format output

JSON

HTML

PDF

api.whats91.com

GET/api/v1/ledger

Fetch ledger data

HTTPS

Bearer Token

Multi-Company

Rate Limited

Sub-100ms response time

24/7 Available

JSON • HTML • PDF

Multi-format output

What is the Whats91 Busy API Engine?

The Whats91 API infrastructure bridges the gap between legacy desktop accounting and modern cloud applications. It provides secure, token-authenticated REST API endpoints that fetch real-time data from Busy Accounting Software. Whether you need standard JSON responses for software integration or ready-to-print HTML/PDF ledgers, our server-driven architecture ensures 24/7 data availability without relying on accountant intervention.

Total Control Over Your Data Retrieval

We don't force you into rigid data structures. Choose the API tier that fits your development needs.

Capability	Standard API	Custom API
Setup Time	Instant deployment	Built to your specifications
Data Scope	Ledgers, Sales, Outstanding, Inventory	100% custom SQL logic
Output Structure	Fixed JSON schema	Developer-defined JSON schema
Filtering	Standard date & party filters	Advanced multi-company & voucher logic
Best For	Fast integrations & dashboards	Complex workflows & proprietary systems

Ledger API

Multi-Format Ledger API: JSON, HTML & PDF

Rendering complex financial ledgers from raw data is a massive development headache. We solved it. Our dedicated Ledger API delivers bill-by-bill outstanding data in three distinct formats, instantly.

JSON Ledger API

Structured raw data payload for deep system integration and custom UI rendering.

Invoice dates & aging details
Debit/credit breakups
Bill-by-bill data
Customer-wise grouping

HTML Ledger API

Beautifully formatted, responsive HTML ledger. Inject directly into portals with zero front-end coding.

Responsive design
Print-ready styling
Zero CSS needed
Instant integration

PDF Ledger API

Ready-to-share, printable PDF generated on the fly. Perfect for email workflows and WhatsApp sharing.

Professional formatting
Auto-generated
Email attachments
WhatsApp ready

API Endpoints

Ready-to-Use Endpoints

Standard API endpoints available instantly after configuration

GET/api/v1/ledger

Fetch ledger data

GET/api/v1/outstanding

Outstanding bills

GET/api/v1/sales

Sales summary

GET/api/v1/inventory

Stock levels

GET/api/v1/ledger/html

HTML formatted ledger

GET/api/v1/ledger/pdf

PDF ledger document

Developer Note: All endpoints support filtering by date range, company, and party. Custom endpoints can be built for any data in your Busy database.

Security & Infrastructure

Secure, Controlled, and Always Online

Your financial database is your most critical asset. Our API architecture ensures absolute protection and high availability.

Token-Based Authentication

Strict API key and bearer token validation

Company Isolation

Enforce company-wise data boundaries

IP Whitelisting

Restrict access to trusted networks

99.99% Uptime

Stable response times, 24/7 availability

Where Can You Flow Your Busy Data?

With a reliable API connection, your development team can build limitless automated workflows

CRM Integration

Salesforce, HubSpot, Zoho CRM

E-commerce Portals

B2B ordering platforms

BI Tools

PowerBI, Tableau dashboards

Custom Mobile Apps

iOS & Android applications

Get API access in 4 steps

Technical Scoping Call

Define your data requirements and integration goals

API Configuration

Set up endpoints, authentication, and data mappings

Development Access

Receive API keys, documentation, and sandbox access

Go Live

Deploy to production with monitoring and support

Standard API: Instant access • Custom API: 2-4 weeks

Frequently Asked Questions

Connect Your Busy Software to the Modern Web

Stop relying on manual exports and fragile workarounds. Give your development team the clean, secure, and reliable API endpoints they need.