README

Official License Bridge WordPress SDK. Add it to your plugin or theme to enable:

License storage and validation
Secure checkout landing page (hosted by License Bridge)
Automatic upgrade from free to premium after purchase
Recurring payments (subscriptions)
Automatic plugin updates for licensed customers

Requirements

PHP 7.2 or higher
WordPress 6.4 or higher (tested up to 6.7+)
Composer (recommended)

Installation

composer require license-bridge/wordpress-sdk

Commit composer.json and composer.lock. Do not edit files inside vendor/ directly.

Quick integration

Create a helper function in your main plugin file (rename my_license to something unique to your plugin):

if (!function_exists('my_license')) {
    function my_license()
    {
        global $my_license;

        if ($my_license) {
            return $my_license;
        }

        if (!file_exists(__DIR__ . '/vendor/autoload.php')) {
            return null;
        }

        require_once __DIR__ . '/vendor/autoload.php';
        include __DIR__ . '/vendor/license-bridge/wordpress-sdk/src/Boot/bootstrap.php';

        $my_license = \LicenseBridge\WordPressSDK\Boot\Loader::register(__FILE__, [
            'plugin-slug'          => plugin_basename(__FILE__),
            'license-product-slug' => 'my-first-product',
        ]);

        return $my_license;
    }

    my_license();
}

Loader::register() automatically wires:

Hidden admin callback page (post-purchase license storage)
Premium plugin upgrade
WordPress update API integration

You do not need to manually instantiate internal SDK classes.

Configuration

Pass these keys to Loader::register() (merged with SDK defaults):

Key	Required	Default	Description
`plugin-slug`	Yes	—	`plugin_basename(__FILE__)`
`license-product-slug`	Yes	—	Product slug on License Bridge
`license-bridge-url`	No	`https://licensebridge.com`	Market / checkout base URL
`license-bridge-api-url`	No	`https://app.licensebridge.com`	API base URL (OAuth, license, updates)
`license-bridge-oauth-token-uri`	No	`/oauth/token`	OAuth token path
`provisioning-key`	For imported-license migration	—	Product provisioning key from License Bridge admin (import page). Required for automatic OAuth provisioning when only a license key is stored locally
`plugin-transient-cache-expire`	No	`43200` (12h)	Plugin details cache (seconds)
`cache-expire`	No	`3600` (1h)	General cache (seconds)

Local / staging example

$my_license = \LicenseBridge\WordPressSDK\Boot\Loader::register(__FILE__, [
    'plugin-slug'            => plugin_basename(__FILE__),
    'license-product-slug'   => 'my-first-product',
    'license-bridge-url'     => 'http://market.lb.test',
    'license-bridge-api-url' => 'https://your-tunnel.ngrok-free.app',
]);

Usage

Access the SDK via your helper or global:

$bridge = my_license();
$slug   = plugin_basename(__FILE__);

Purchase link

$link = $bridge->purchase_link($slug);
// https://licensebridge.com/market/my-first-product?callback_url=...

Use in a button:

echo '<a href="' . esc_url($link) . '">Buy Premium</a>';

Inline checkout (wp-admin modal) — SDK 2.0+

Keep customers inside WordPress admin with a billing modal. Supports Paddle overlay and Stripe Elements. PayPal still uses the hosted purchase link (redirect).

Fixed plan on the button:

echo my_license()->checkout_button($slug, [
    'plugin-file' => __FILE__,
    'gateway'     => 'paddle', // or stripe
    'plan-slug'   => 'pro',
    'plan-type'   => 'annual',
    'label'       => 'Upgrade to Pro',
]);

Let the customer pick a plan:

echo my_license()->checkout_button($slug, [
    'plugin-file'          => __FILE__,
    'gateway'              => 'stripe',
    'allow-plan-selection' => true,
]);

Key	Description
`plugin-file`	Main plugin file path (`__FILE__`) so SDK assets load from `vendor/license-bridge/wordpress-sdk/assets`
`gateway`	`paddle` or `stripe`
`plan-slug`	Fixed plan slug (optional when `allow-plan-selection` is true)
`plan-type`	`month`, `annual`, or `life` (optional; inferred from API when omitted)
`allow-plan-selection`	Show plan / billing-cycle selectors
`label`	Button text

The hosted market link remains available as a fallback via purchase_link().

Check license

if ($bridge->license_exists($slug)) {
    // Credentials stored locally
}

if ($bridge->is_license_active($slug)) {
    // Active license on License Bridge
}

License details

$details = $bridge->license($slug); // array|false

Example fields: full_name, email, plan_type, active, subscribed, subscription, etc.

Cancel subscription

if ($bridge->cancel_license($slug)) {
    // Cancelled on License Bridge
}

Post-purchase flow

After checkout, License Bridge redirects the customer to your WordPress admin. The SDK:

Verifies the nonce
Stores lk, client_id, client_secret
Runs premium plugin upgrade (if a newer package is available)
Redirects to Plugins screen:
- wp-admin/plugins.php?license_upgraded=1 — upgrade ran
- wp-admin/plugins.php?license_saved=1 — license saved, no newer version

Show admin feedback:

add_action('admin_notices', function () {
    if (isset($_GET['license_upgraded'])) {
        echo '<div class="notice notice-success"><p>Premium activated.</p></div>';
    }
});

Important: Premium version on License Bridge must be higher than the installed free version for auto-upgrade to run.

Imported license migration (Freemius and other platforms)

When you import licenses from another platform, License Bridge preserves each customer's original license key. OAuth credentials are not created during import and do not need to be distributed manually.

Embed your product provisioning key (shown on the License Bridge import page) in the plugin SDK config:

$my_license = \LicenseBridge\WordPressSDK\Boot\Loader::register(__FILE__, [
    'plugin-slug'          => plugin_basename(__FILE__),
    'license-product-slug' => 'my-first-product',
    'provisioning-key'     => 'your-product-provisioning-key',
]);

When a site already stores the imported license key but has no OAuth credentials yet, the SDK automatically provisions credentials on the first connection. The customer does not configure OAuth manually.

If OAuth credentials were already stored (for example after checkout), the SDK continues using them and does not call provisioning again.

OAuth provisioning happens once per license. Existing credentials are never rotated or re-exposed through the provisioning endpoint.

This feature does not migrate subscription billing, payment-provider subscriptions, activation history, or remote renewal. Imported licenses keep their local entitlement dates only.

Hooks

// Before/after upgrade (callback handler)
apply_filters('before_upgrade_plugin_' . $plugin_slug, '');
apply_filters('after_upgrade_plugin_' . $plugin_slug, '');

Example plugin

See license-example-plugin for a full working integration.

License

Licensed under the GNU General Public License v3.0.

license-bridge / wordpress-sdk

Package info

Security

Statistics