ForkOST Developer API & Webhooks: Connecting Custom E-Commerce & ERP Systems (2026)

As growing businesses scale, their technology stack expands to include custom web applications, mobile apps, proprietary e-commerce storefronts, and third-party logistics (3PL) platforms.

We built the ForkOST Developer API & Webhooks Infrastructure to give engineering teams, software partners, and system integrators complete programmatic control over accounting, inventory, billing, and GST workflows.

Using RESTful JSON endpoints, OAuth2 / API Key authentication, and real-time Webhook subscriptions, developers can build custom integrations that create sales vouchers, sync stock levels, query customer ledgers, and trigger automated GST filings.

In this comprehensive developer guide, we explore ForkOST API architecture: authentication, core endpoints, webhook event payload schemas, SDK libraries, rate limits, and integration code examples.

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1. Developer Platform Architecture

  External Custom App / E-Commerce                 ForkOST Developer Platform
  ┌──────────────────────────────┐                ┌──────────────────────────────────┐
  │ Custom Web Store / Mobile App│ ─────────────► │ REST API (OAuth2 / Bearer Token) │
  │ 3PL Warehouse System         │ ◄───────────── │ Real-Time Webhooks (JSON Push)   │
  └──────────────────────────────┘                └──────────────────────────────────┘

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2. Authentication & Security

ForkOST APIs support secure, bank-grade authentication methods:

• API Keys (Server-to-Server): Generate secret API tokens inside ForkOST Settings for backend server integrations.
• OAuth 2.0 (Third-Party App Partner Integration): Authorization Code Flow for third-party marketplace integrations.
• TLS 1.3 Encryption: All API traffic is strictly encrypted over HTTPS.

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3. Core API Endpoints Overview

HTTP Method	Endpoint Path	Description
POST	/api/v1/vouchers/sales	Create a new GST Sales Invoice voucher
GET	/api/v1/inventory/items	Query stock balance and SKU pricing
PATCH	/api/v1/inventory/items/{id}	Update stock quantities or master prices
GET	/api/v1/parties/ledgers	Fetch customer/supplier ledger balances
POST	/api/v1/payments/receipts	Record customer payment receipt vouchers

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4. Real-Time Webhook Subscriptions

Webhooks push real-time event notifications to your server endpoint within milliseconds of an action occurring inside ForkOST:

Supported Webhook Events:

• invoice.created: Triggered when a new sales invoice is generated.
• inventory.low_stock: Triggered when item stock breaches safety reorder points.
• payment.received: Triggered when a customer payment is credited via UPI/Bank.
• gst.return_filed: Triggered when a GSTR-1 or GSTR-3B return filing completes.

Sample JSON Webhook Payload (invoice.created):

{
  "event": "invoice.created",
  "timestamp": "2026-08-02T14:30:00Z",
  "data": {
    "invoice_id": "inv_987654321",
    "invoice_number": "INV-2026-0891",
    "customer_name": "Apex Retail Solutions",
    "total_amount": 118000.00,
    "cgst": 9000.00,
    "sgst": 9000.00,
    "status": "published"
  }
}

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5. Developer Code Example: Creating a Sales Voucher (Node.js)

const response = await fetch('https://api.forkost.com/v1/vouchers/sales', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_SECRET_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    customer_gstin: '27AAAAA0000A1Z5',
    place_of_supply: '27',
    items: [
      { sku: 'ITEM-9988', qty: 10, unit_price: 1500, gst_rate: 18 }
    ]
  })
});
const data = await response.json();
console.log('Created Invoice ID:', data.invoice_id);

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6. Frequently Asked Questions (FAQ)

Q1: What are the API rate limits?

Standard Pro accounts support 1,000 API requests per minute. Enterprise accounts offer custom rate limits up to 10,000 requests per minute.

Q2: Are official SDK libraries available?

Yes! Official SDK libraries are available for Node.js / TypeScript, Python, and PHP (Laravel).

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7. Conclusion

ForkOST Developer APIs and Webhooks provide the digital bridge to connect your custom software applications with enterprise accounting, inventory, and GST compliance.

👉 Explore ForkOST Developer Portal — Generate API keys, read full OpenAPI / Swagger docs, and test endpoints in our Sandbox environment.
👉 Read Full API Docs at ForkOST Developer Hub — code samples, webhook guides, and SDK downloads.