ShipLabel Developer Reference

Constants

Constant	Description
`SHIPLABEL_VERSION`	Plugin version
`SHIPLABEL_FILE`	Absolute path to the main plugin file
`SHIPLABEL_PATH`	Plugin directory path
`SHIPLABEL_URL`	Plugin URL
`SHIPLABEL_LABELS_DIR`	Absolute path of the label file folder (`uploads/shiplabel-labels/`)
`SHIPLABEL_LABELS_URL`	URL of the label file folder (not publicly accessible)
`SHIPLABEL_LICENSE_OPTION`	Option name storing the license key
`SHIPLABEL_LICENSE_STATUS_OPTION`	Option name storing the license status

Class Map

Class	File
`ShipLabel_Admin`	`includes/admin/class-shiplabel-admin.php`
`ShipLabel_Admin_Bulk_Actions`	`includes/admin/class-shiplabel-admin-bulk-actions.php`
`ShipLabel_Admin_Order_List_Column`	`includes/admin/class-shiplabel-admin-order-list-column.php`
`ShipLabel_Admin_Order_Metabox`	`includes/admin/class-shiplabel-admin-order-metabox.php`
`ShipLabel_REST_Controller`	`includes/api/class-shiplabel-rest-controller.php`
`ShipLabel_Carrier_Base`	`includes/carriers/class-shiplabel-carrier-base.php`
`ShipLabel_USPS_API`	`includes/carriers/class-shiplabel-usps-api.php`
`ShipLabel_FedEx_API`	`includes/carriers/class-shiplabel-fedex-api.php`
`ShipLabel_USPS_Shipping_Provider`	`includes/carriers/class-shiplabel-usps-shipping-provider.php`
`ShipLabel_FedEx_Shipping_Provider`	`includes/carriers/class-shiplabel-fedex-shipping-provider.php`
`ShipLabel_Shipping_Method_USPS`	`includes/class-shiplabel-shipping-method-usps.php`
`ShipLabel_Shipping_Method_FedEx`	`includes/class-shiplabel-shipping-method-fedex.php`
`ShipLabel_Settings`	`includes/class-shiplabel-settings.php`
`ShipLabel_Install`	`includes/class-shiplabel-install.php`
`ShipLabel_Tracking_Webhook`	`includes/class-shiplabel-tracking-webhook.php`
`ShipLabel_Fulfillment_Manager`	`includes/fulfillment/class-shiplabel-fulfillment-manager.php`
`ShipLabel_Label_Store`	`includes/fulfillment/class-shiplabel-label-store.php`

REST Namespace

shiplabel/v1 - see REST API for the full endpoint list.

Cron Events

Hook	Schedule	Description
`shiplabel_sync_tracking_statuses`	Twice daily	Polls carriers for tracking updates on up to 100 active labels, then deletes label files past the retention period

AJAX Actions

Action	Description
`shiplabel_save_settings`	Unified settings save (all tabs)
`shiplabel_reset_settings`	Reset settings, preserving credentials, USPS payment account and shipper address
`shiplabel_test_connection`	Test USPS/FedEx sign-in credentials
`shiplabel_validate_address`	Validate an address against USPS or FedEx
`shiplabel_license_action`	Activate/deactivate the license key

Filters

Filter	Arguments	Description
`shiplabel_fulfillment_class`	`$class (string)`	Override the WooCommerce Fulfillment class ShipLabel instantiates in Order Fulfillments Mode
`shiplabel_fedex_customs_commodity`	`$commodity (array)`, `$item (array)`, `$params (array)`	Filter one customs line of a FedEx international label - e.g. add a harmonized (HS) code or change `countryOfManufacture`. `$item` has `description`, `quantity` and `unit_value`; `$params` is the full label request

Example - add an HS code to every customs line:

add_filter( 'shiplabel_fedex_customs_commodity', function ( array $commodity, array $item ) {
    $commodity['harmonizedCode'] = '6505.00';
    return $commodity;
}, 10, 2 );

Actions Fired

Action	When
`woocommerce_fulfillment_created_notification`	WooCommerce's own hook, fired after ShipLabel creates a fulfillment marked Fulfilled, so WooCommerce sends its customer email

Data Storage

Name	Type	Contents
`{prefix}shiplabel_labels`	Table	One row per label: order, carrier, service, tracking number, file, cost, status
`{prefix}shiplabel_tracking_events`	Table	Tracking events per label
`shiplabel_settings`	Option	All settings below
`shiplabel_webhook_secret`	Option	Tracking webhook secret (blank = unsigned requests accepted)
`shiplabel_usps_token`, `shiplabel_fedex_token`	Transients	Carrier sign-in tokens
`shiplabel_usps_payment_token`	Transient	USPS payment authorization, kept 7 hours
`shiplabel_usps_rates_`, `shiplabel_fedex_rates_`	Transients	Checkout rate cache, 30 minutes

Saving settings clears the carrier and USPS payment tokens.

Default Settings

Stored in the shiplabel_settings option (ShipLabel_Settings::defaults()):

Key	Default	Description
`usps_enabled` / `fedex_enabled`	`no`	Carrier master toggles
`usps_env` / `fedex_env`	`production`	`production` or `sandbox`
`usps_client_id`, `usps_client_secret`	-	USPS app credentials
`usps_crid`, `usps_mid`, `usps_eps_account`	-	USPS payment account, needed for labels
`usps_manifest_mid`	-	Optional; falls back to `usps_mid`
`fedex_client_id`, `fedex_client_secret`, `fedex_account_number`	-	FedEx credentials and account
`usps_default_service`	`PRIORITY_MAIL`	-
`fedex_default_service`	`FEDEX_GROUND`	-
`usps_label_format` / `fedex_label_format`	`PDF`	USPS: `PDF`, `TIFF`. FedEx: `PDF`, `PNG`, `ZPLII`
`shipper_country`	`US`	-
`default_carrier`	`usps`	`usps` or `fedex`
`default_weight_unit`	`oz`	-
`default_dim_unit`	`in`	-
`default_package_type`	`package`	-
`auto_generate_label`	`no`	-
`auto_fulfill_on_label`	`no`	-
`label_file_retention`	`90`	Days
`debug_mode`	`no`	-

The license key and status are stored as separate options, not inside shiplabel_settings.

Service Codes

USPS: PRIORITY_MAIL_EXPRESS, PRIORITY_MAIL, USPS_GROUND_ADVANTAGE, FIRST-CLASS_PACKAGE_SERVICE, MEDIA_MAIL, LIBRARY_MAIL

FedEx: FEDEX_GROUND, GROUND_HOME_DELIVERY, FEDEX_2_DAY, FEDEX_2_DAY_AM, FEDEX_EXPRESS_SAVER, STANDARD_OVERNIGHT, PRIORITY_OVERNIGHT, FIRST_OVERNIGHT, INTERNATIONAL_ECONOMY, FEDEX_INTERNATIONAL_PRIORITY, FEDEX_INTERNATIONAL_CONNECT_PLUS

The older INTERNATIONAL_PRIORITY code is still accepted and treated as FEDEX_INTERNATIONAL_PRIORITY.

Troubleshooting Overview