less than a minute read • Updated 2 hours ago
HMAC excluded parameters reference
Parameters that do not need to be signed when using HMAC product validation.
When HMAC validation is enabled, most product parameters must be signed. The following parameters are exempt — signing them is unnecessary and may cause errors.
Cart options
Parameter | Description |
|---|---|
| Cart action (e.g. |
| Session ID |
| Empties the cart |
| Coupon code |
| Output format (e.g. |
| Subscription token |
| Redirect URL after add to cart |
| JSONP callback |
| Cache-busting parameter |
| Locale override |
Checkout prepopulation
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Name prefixes
Parameters using the following name prefixes are also exempt:
Prefix | Description |
|---|---|
| Session variables — visible server-side only, not in the cart |
| Excluded variables — passed through to the datafeed but ignored by the cart |
| Double underscore — internal use |