B2C Commerce Hooks

Hooks are extension points that allow you to customize business logic by registering scripts. B2C Commerce supports two types of hooks:

OCAPI/SCAPI Hooks - Extend API resources with before, after, and modifyResponse hooks
System Hooks - Custom extension points for order calculation, payment, and other core functionality

Hook Types Overview

Type	Purpose	Examples
OCAPI/SCAPI	Extend API behavior	`dw.ocapi.shop.basket.afterPOST`
System	Core business logic	`dw.order.calculate`
Custom	Your own extension points	`app.checkout.validate`

Hook Registration

File Structure

my_cartridge/
├── package.json           # References hooks.json
└── cartridge/
    └── scripts/
        ├── hooks.json     # Hook registrations
        └── hooks/         # Hook implementations
            ├── basket.js
            └── order.js

package.json

Reference the hooks configuration file:

{
  "name": "my_cartridge",
  "hooks": "./cartridge/scripts/hooks.json"
}

hooks.json

{
  "hooks": [
    {
      "name": "dw.ocapi.shop.basket.afterPOST",
      "script": "./hooks/basket.js"
    },
    {
      "name": "dw.ocapi.shop.basket.modifyPOSTResponse",
      "script": "./hooks/basket.js"
    },
    {
      "name": "dw.order.calculate",
      "script": "./hooks/order.js"
    }
  ]
}

Hook Script

Export functions matching the hook method name (without package prefix):

// hooks/basket.js
var Status = require('dw/system/Status');

exports.afterPOST = function(basket) {
    // Called after basket creation
    // Returning a value would skip system implementation
};

exports.modifyPOSTResponse = function(basket, basketResponse) {
    // Modify the API response
    basketResponse.c_customField = 'value';
};

HookMgr API

Use dw.system.HookMgr to call hooks programmatically:

var HookMgr = require('dw/system/HookMgr');

// Check if hook exists
if (HookMgr.hasHook('dw.order.calculate')) {
    // Call the hook
    var result = HookMgr.callHook('dw.order.calculate', 'calculate', basket);
}

Method	Description
`hasHook(extensionPoint)`	Returns true if hook is registered or has default implementation
`callHook(extensionPoint, functionName, args...)`	Calls the hook, returns result or undefined

Status Object

Hooks return dw.system.Status to indicate success or failure:

var Status = require('dw/system/Status');

// Success - continue processing
return new Status(Status.OK);

// Error - stop processing, rollback transaction
var status = new Status(Status.ERROR);
status.addDetail('error_code', 'INVALID_ADDRESS');
status.addDetail('message', 'Address validation failed');
return status;

Status	HTTP Response	Behavior
`Status.OK`	Continues	Hook execution continues
`Status.ERROR`	400 Bad Request	Transaction rolled back, processing stops
Uncaught exception	500 Internal Error	Transaction rolled back

Return Value Behavior (Important)

OCAPI/SCAPI hooks that return ANY value will SKIP the system implementation and all subsequent registered hooks for that extension point.

This is a common source of bugs. For example, if a hook returns Status.OK, the system's dw.order.calculate implementation won't run, causing cart totals to be incorrect.

When to Return a Value

Return a Status object only when you want to:

Stop processing with an error (Status.ERROR)
Skip the system implementation intentionally

When NOT to Return a Value

To ensure system implementations run (like cart calculation), return nothing:

// Returning Status.OK skips system implementation
exports.afterPOST = function(basket) {
    doSomething(basket);
    return new Status(Status.OK);  // Skips dw.order.calculate
};

// No return value - system implementation runs
exports.afterPOST = function(basket) {
    doSomething(basket);
    // No return, or explicit: return;
};

Summary

Return Value	OCAPI/SCAPI Behavior	Custom Hook Behavior
`undefined` (no return)	System implementation runs, subsequent hooks run	All hooks run
`Status.OK`	Skips system implementation and subsequent hooks	All hooks run
`Status.ERROR`	Stops processing, returns error	All hooks run

Debugging tip: If cart totals are wrong or hooks aren't firing, check if an earlier hook is returning a value.

OCAPI/SCAPI Hooks

OCAPI and SCAPI share the same hooks. Enable in Business Manager: Administration > Global Preferences > Feature Switches > Enable Salesforce Commerce Cloud API hook execution

Hook Types

Hook	When Called	Use Case
`before<METHOD>`	Before processing	Validation, access control
`after<METHOD>`	After processing (in transaction)	Data modification, external calls
`modify<METHOD>Response`	Before response sent	Add/modify response properties

Common Hook Patterns

// Validation in beforePUT
exports.beforePUT = function(basket, addressDoc) {
    if (!isValidAddress(addressDoc)) {
        var status = new Status(Status.ERROR);
        status.addDetail('validation_error', 'Invalid address');
        return status;
    }
};

// External call in afterPOST (within transaction)
exports.afterPOST = function(basket, paymentDoc) {
    var result = callPaymentService(paymentDoc);
    request.custom.paymentResult = result; // Pass to modifyResponse
    // Returning a Status would skip system implementation
};

// Modify response
exports.modifyPOSTResponse = function(basket, basketResponse, paymentDoc) {
    basketResponse.c_paymentStatus = request.custom.paymentResult.status;
};

Passing Data Between Hooks

Use request.custom to pass data between hooks in the same request:

// In afterPOST
exports.afterPOST = function(basket, doc) {
    request.custom.externalId = callExternalService();
};

// In modifyPOSTResponse
exports.modifyPOSTResponse = function(basket, response, doc) {
    response.c_externalId = request.custom.externalId;
};

Detect SCAPI vs OCAPI

exports.afterPOST = function(basket) {
    if (request.isSCAPI()) {
        // SCAPI-specific logic
    } else {
        // OCAPI-specific logic
    }
};

System Hooks

Calculate Hooks

Extension Point	Function	Purpose
`dw.order.calculate`	`calculate`	Full basket/order calculation
`dw.order.calculateShipping`	`calculateShipping`	Shipping calculation
`dw.order.calculateTax`	`calculateTax`	Tax calculation

// hooks/calculate.js
var Status = require('dw/system/Status');
var HookMgr = require('dw/system/HookMgr');

exports.calculate = function(lineItemCtnr) {
    // Calculate shipping
    HookMgr.callHook('dw.order.calculateShipping', 'calculateShipping', lineItemCtnr);

    // Calculate promotions, totals...

    // Calculate tax
    HookMgr.callHook('dw.order.calculateTax', 'calculateTax', lineItemCtnr);

    return new Status(Status.OK);
};

Payment Hooks

Extension Point	Function	Purpose
`dw.order.payment.authorize`	`authorize`	Payment authorization
`dw.order.payment.capture`	`capture`	Capture authorized payment
`dw.order.payment.refund`	`refund`	Refund payment
`dw.order.payment.validateAuthorization`	`validateAuthorization`	Check authorization validity
`dw.order.payment.reauthorize`	`reauthorize`	Re-authorize expired auth

Order Hooks

Extension Point	Function	Purpose
`dw.order.createOrderNo`	`createOrderNo`	Custom order number generation

var OrderMgr = require('dw/order/OrderMgr');
var Site = require('dw/system/Site');

exports.createOrderNo = function() {
    var seqNo = OrderMgr.createOrderSequenceNo();
    var prefix = Site.current.ID;
    return prefix + '-' + seqNo;
};

Custom Hooks

Create your own extension points:

// Define custom hook
var HookMgr = require('dw/system/HookMgr');

function processCheckout(basket) {
    // Call custom hook if registered
    if (HookMgr.hasHook('app.checkout.validate')) {
        var status = HookMgr.callHook('app.checkout.validate', 'validate', basket);
        if (status && status.error) {
            return status;
        }
    }
    // Continue processing...
}

{
  "hooks": [
    {
      "name": "app.checkout.validate",
      "script": "./hooks/checkout.js"
    }
  ]
}

Custom hooks always execute all registered implementations regardless of return value.

Remote Includes in Hooks

Enhance API responses with data from other SCAPI endpoints:

var RESTResponseMgr = require('dw/system/RESTResponseMgr');

exports.modifyGETResponse = function(product, doc) {
    // Include Custom API response
    var include = RESTResponseMgr.createScapiRemoteInclude(
        'custom',           // API family
        'my-api',           // API name
        'v1',               // Version
        'endpoint'          // Endpoint
    );
    doc.c_additionalData = { value: [include] };
};

Best Practices

Return undefined (no return) from OCAPI/SCAPI hooks to ensure system implementations run
Only return Status.ERROR when you need to stop processing
Returning Status.OK skips system implementation and subsequent hooks
Use request.custom to pass data between hooks
Check request.isSCAPI() when supporting both APIs
Keep hooks focused and performant
Use custom properties (c_ prefix) in modifyResponse
Avoid transactions in calculate hooks (breaks SCAPI)
Avoid slow external calls in beforeGET (affects caching)

Error Handling

Circuit Breaker

Too many hook errors triggers circuit breaker (HTTP 503):

{
  "title": "Hook Circuit Breaker",
  "type": "https://api.commercecloud.salesforce.com/.../hook-circuit-breaker",
  "detail": "Failure rate above threshold of '50%'",
  "extensionPointName": "dw.ocapi.shop.basket.afterPOST"
}

Timeout

Hooks must complete within the SCAPI timeout (HTTP 504 on timeout).

Detailed References

OCAPI/SCAPI Hooks - API hook patterns and available hooks
System Hooks - Calculate, payment, and order hooks

b2c-hooks