Add Grafana dashboard and wp-prometheus integration (v0.7.5)

- Add example Grafana dashboard with 24 panels for license metrics
- Register dashboard with wp-prometheus via hook
- Add dashboard documentation with PromQL examples and alerting rules
- Update README with monitoring section

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -4,3 +4,6 @@ wp-plugins
 wp-core
 vendor/
 releases/*
+
+# Marketing texts (not part of plugin distribution)
+MARKETING.md

CHANGELOG.md

@@ -7,6 +7,28 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.7.5] - 2026-02-03
+
+### Added
+
+- **Grafana Dashboard**: Example dashboard for license metrics monitoring
+  - 24 panels organized into 4 sections: License Overview, Downloads & Versions, API Metrics, Errors & Rate Limiting
+  - Template variables for data source and instance filtering
+  - Includes example Prometheus alerting rules
+- **WP Prometheus Dashboard Integration**: Dashboard automatically registered with wp-prometheus
+  - Appears in Settings > WP Prometheus > Dashboards when metrics are enabled
+  - Uses `wp_prometheus_register_dashboards` hook for seamless integration
+- Documentation for Grafana dashboard installation and PromQL query examples
+
+### New Files
+
+- `docs/grafana-dashboard.json` - Complete Grafana dashboard with 24 panels
+- `docs/grafana-dashboard.md` - Installation and usage documentation
+
+### Changed
+
+- Updated README with "Monitoring with Prometheus & Grafana" section
+
 ## [0.7.4] - 2026-02-03
 
 ### Added

CLAUDE.md

@@ -1990,3 +1990,80 @@ Added `ResponseSigner::getServerSecret()` static method that checks multiple sou
 - The fix maintains backward compatibility with standard WordPress installations using constants
 - Docker environments can now use environment variables directly without needing the constant to be defined
 - All three methods (`isSigningEnabled()`, `getCustomerSecretForLicense()`, and constructor) now use the centralized `getServerSecret()` method
+
+### 2026-02-03 - Version 0.7.4 - Prometheus Metrics Integration
+
+**Overview:**
+
+Added Prometheus metrics integration to expose license and API metrics for monitoring. Requires the WP Prometheus plugin.
+
+**New files:**
+
+- `src/Metrics/PrometheusController.php` - Prometheus metrics collection controller
+
+**Implemented:**
+
+- New "Metrics" settings section with enable/disable toggle
+- Hooks into `wp_prometheus_collect_metrics` action for metric collection
+- License gauges using existing `LicenseManager::getStatistics()`:
+  - `wclp_licenses_total{status}` - License counts by status
+  - `wclp_licenses_lifetime_total` - Lifetime licenses count
+  - `wclp_licenses_expiring_total` - Expiring licenses count
+  - `wclp_licenses_expiring_soon` - Licenses expiring within 30 days
+- Download gauges using existing `VersionManager::getDownloadStatistics()`:
+  - `wclp_downloads_total` - Total downloads
+  - `wclp_versions_active_total` - Active product versions
+- API counters (stored in WordPress options for persistence):
+  - `wclp_api_requests_total{endpoint,result}` - API requests by endpoint and result
+  - `wclp_rate_limit_exceeded_total{endpoint}` - Rate limit exceeded events
+  - `wclp_validation_errors_total{error_type}` - Validation errors by type
+
+**Modified files:**
+
+- `src/Admin/SettingsController.php` - Added 'metrics' section with settings
+- `src/Api/RestApiController.php` - Added metric tracking for API requests
+- `src/Api/UpdateController.php` - Added metric tracking for update-check requests
+- `src/Plugin.php` - Initialize PrometheusController
+
+**Technical notes:**
+
+- Metrics are only collected when enabled via settings toggle
+- Static methods allow increment from API controllers without dependency injection
+- Counter values persist across requests via `wclp_prometheus_counters` option
+- Gauges query database on each metric collection (uses existing statistics methods)
+
+### 2026-02-03 - Grafana Dashboard & WP Prometheus Integration
+
+**Overview:**
+
+Added example Grafana dashboard JSON and integrated with wp-prometheus dashboard registration system.
+
+**New files:**
+
+- `docs/grafana-dashboard.json` - Complete Grafana dashboard with 24 panels
+- `docs/grafana-dashboard.md` - Installation and usage documentation
+
+**Dashboard panels:**
+
+- License Overview: Total, Active, Lifetime, Expiring Soon, Expired, Revoked stats + pie chart + time series
+- Downloads & Versions: Total downloads, active versions, download trends
+- API Metrics: Request rates by endpoint/result, pie chart breakdown, top requests table
+- Errors & Rate Limiting: Rate limit events, validation errors by type over time
+
+**WP Prometheus integration:**
+
+- Dashboard automatically registered via `wp_prometheus_register_dashboards` hook
+- Appears in Settings > WP Prometheus > Dashboards tab when metrics are enabled
+- Uses file-based registration with metadata (title, description, icon, plugin attribution)
+
+**Modified files:**
+
+- `src/Metrics/PrometheusController.php` - Added `registerDashboard()` method and hook registration
+- `docs/grafana-dashboard.md` - Added wp-prometheus installation option as recommended method
+- `README.md` - Added "Monitoring with Prometheus & Grafana" section linking to dashboard docs
+
+**Technical notes:**
+
+- Dashboard registration only occurs when metrics are enabled (same condition as metric collection)
+- Uses `dashicons-admin-network` icon for dashboard list
+- File path uses `WC_LICENSED_PRODUCT_PLUGIN_DIR` constant for reliable path resolution

README.md

@@ -393,6 +393,38 @@ The plugin sends automatic email notifications (configurable via WooCommerce > S
 - **Expiration Warning (1 day)**: Urgent reminder sent 1 day before expiration
 - **License Expired**: Notification when a license auto-expires
 
+## Monitoring with Prometheus & Grafana
+
+The plugin integrates with [wp-prometheus](https://src.bundespruefstelle.ch/magdev/wp-prometheus) to expose metrics for monitoring and alerting.
+
+### Enable Metrics
+
+1. Install and configure the wp-prometheus plugin
+2. Go to WooCommerce > Settings > Licensed Products > Metrics
+3. Enable "Prometheus Metrics"
+
+### Available Metrics
+
+**Gauges:**
+
+- `wclp_licenses_total{status}` - License counts by status
+- `wclp_licenses_lifetime_total` - Lifetime licenses
+- `wclp_licenses_expiring_soon` - Licenses expiring within 30 days
+- `wclp_downloads_total` - Total file downloads
+- `wclp_versions_active_total` - Active product versions
+
+**Counters:**
+
+- `wclp_api_requests_total{endpoint,result}` - API requests by endpoint and result
+- `wclp_rate_limit_exceeded_total{endpoint}` - Rate limit events
+- `wclp_validation_errors_total{error_type}` - Validation errors by type
+
+### Grafana Dashboard
+
+An example Grafana dashboard is included at [docs/grafana-dashboard.json](docs/grafana-dashboard.json).
+
+See [docs/grafana-dashboard.md](docs/grafana-dashboard.md) for installation instructions, panel descriptions, and alerting examples.
+
 ## Changelog
 
 See [CHANGELOG.md](CHANGELOG.md) for version history and changes.

docs/grafana-dashboard.md

@@ -0,0 +1,219 @@
+# Grafana Dashboard for WC Licensed Product
+
+This dashboard provides comprehensive monitoring for the WC Licensed Product plugin using Prometheus metrics exposed via the [wp-prometheus](https://src.bundespruefstelle.ch/magdev/wp-prometheus) plugin.
+
+## Prerequisites
+
+1. **WP Prometheus Plugin** - Install and configure [wp-prometheus](https://src.bundespruefstelle.ch/magdev/wp-prometheus) on your WordPress site
+2. **Prometheus** - Configure Prometheus to scrape your WordPress metrics endpoint
+3. **Grafana** - Grafana 9.0+ with Prometheus data source configured
+4. **Enable Metrics** - In WordPress admin: WooCommerce > Settings > Licensed Products > Metrics > Enable Prometheus Metrics
+
+## Installation
+
+### Option 1: Via WP Prometheus Settings (Recommended)
+
+When metrics are enabled, the dashboard is automatically registered with wp-prometheus:
+
+1. Go to **Settings > WP Prometheus** in WordPress admin
+2. Navigate to the **Dashboards** tab
+3. Find "WC Licensed Product - License Metrics" in the list
+4. Click **Download JSON** to get the dashboard file
+5. Import the downloaded file into Grafana
+
+### Option 2: Manual Import
+
+1. Open Grafana and navigate to **Dashboards > Import**
+2. Upload the `grafana-dashboard.json` file or paste its contents
+3. Select your Prometheus data source
+4. Click **Import**
+
+### Configure Variables
+
+The dashboard includes two template variables:
+
+- **datasource** - Select your Prometheus data source
+- **instance** - Filter by WordPress instance (useful for multi-site monitoring)
+
+## Dashboard Panels
+
+### License Overview
+
+| Panel | Description |
+| --- | --- |
+| Total Licenses | Total count of all licenses |
+| Active Licenses | Licenses with `status=active` |
+| Lifetime Licenses | Licenses without expiration date |
+| Expiring Soon (30d) | Licenses expiring within 30 days |
+| Expired Licenses | Licenses with `status=expired` |
+| Revoked Licenses | Licenses with `status=revoked` |
+| Licenses by Status | Pie chart showing distribution |
+| License Status Over Time | Time series of license counts |
+
+### Downloads & Versions
+
+| Panel | Description |
+| --- | --- |
+| Total Downloads | Cumulative download count |
+| Active Product Versions | Number of active versions |
+| Downloads Over Time | Download trend graph |
+| Downloads (Selected Range) | Downloads in selected time range |
+
+### API Metrics
+
+| Panel | Description |
+| --- | --- |
+| API Requests (5m intervals) | Stacked bar chart by endpoint/result |
+| Requests by Endpoint | Donut chart of endpoint distribution |
+| Top API Requests | Table of most frequent requests |
+
+### Errors & Rate Limiting
+
+| Panel | Description |
+| --- | --- |
+| Rate Limit Events (Total) | Total HTTP 429 responses |
+| Validation Errors (Total) | Total validation failures |
+| Validation Errors Over Time | Error trend by type |
+| Validation Errors by Type | Pie chart breakdown |
+| Rate Limit Events by Endpoint | Rate limits per endpoint |
+
+## Metrics Reference
+
+### Gauges (current values)
+
+```promql
+# Licenses by status
+wclp_licenses_total{status="active|expired|revoked|inactive"}
+
+# Lifetime licenses (no expiration)
+wclp_licenses_lifetime_total
+
+# Licenses with expiration date
+wclp_licenses_expiring_total
+
+# Licenses expiring within 30 days
+wclp_licenses_expiring_soon
+
+# Total downloads
+wclp_downloads_total
+
+# Active product versions
+wclp_versions_active_total
+```
+
+### Counters (cumulative)
+
+```promql
+# API requests by endpoint and result
+wclp_api_requests_total{endpoint="validate|status|activate|update-check", result="success|error"}
+
+# Rate limit exceeded events
+wclp_rate_limit_exceeded_total{endpoint="validate|status|activate|update-check"}
+
+# Validation errors by type
+wclp_validation_errors_total{error_type="license_not_found|domain_mismatch|license_expired|license_revoked|..."}
+```
+
+## Example Prometheus Queries
+
+### Success Rate
+
+```promql
+sum(rate(wclp_api_requests_total{result="success"}[5m])) /
+sum(rate(wclp_api_requests_total[5m])) * 100
+```
+
+### Error Rate by Endpoint
+
+```promql
+sum by (endpoint) (rate(wclp_api_requests_total{result="error"}[5m]))
+```
+
+### License Churn (new activations)
+
+```promql
+increase(wclp_licenses_total{status="active"}[1d])
+```
+
+### Top Validation Errors
+
+```promql
+topk(5, sum by (error_type) (wclp_validation_errors_total))
+```
+
+## Alerting Examples
+
+Add these alerts to your Prometheus alerting rules:
+
+```yaml
+groups:
+  - name: wc-licensed-product
+    rules:
+      # High rate limit events
+      - alert: HighRateLimitEvents
+        expr: increase(wclp_rate_limit_exceeded_total[5m]) > 10
+        for: 5m
+        labels:
+          severity: warning
+        annotations:
+          summary: "High rate limiting on {{ $labels.endpoint }}"
+
+      # Many expiring licenses
+      - alert: LicensesExpiringSoon
+        expr: wclp_licenses_expiring_soon > 20
+        for: 1h
+        labels:
+          severity: info
+        annotations:
+          summary: "{{ $value }} licenses expiring within 30 days"
+
+      # API error rate
+      - alert: HighAPIErrorRate
+        expr: |
+          sum(rate(wclp_api_requests_total{result="error"}[5m])) /
+          sum(rate(wclp_api_requests_total[5m])) > 0.1
+        for: 10m
+        labels:
+          severity: warning
+        annotations:
+          summary: "API error rate above 10%"
+```
+
+## Prometheus Configuration
+
+Add to your `prometheus.yml`:
+
+```yaml
+scrape_configs:
+  - job_name: 'wordpress'
+    metrics_path: '/metrics'
+    scheme: https
+    bearer_token: 'YOUR_WP_PROMETHEUS_TOKEN'
+    static_configs:
+      - targets: ['your-wordpress-site.com']
+```
+
+## Troubleshooting
+
+### No data showing
+
+1. Verify wp-prometheus is installed and configured
+2. Check that metrics are enabled in WC Licensed Product settings
+3. Confirm Prometheus can reach your WordPress metrics endpoint
+4. Check the data source selection in Grafana
+
+### Missing metrics
+
+Some metrics only appear after relevant actions occur:
+
+- `wclp_api_requests_total` - After API requests
+- `wclp_rate_limit_exceeded_total` - After rate limit events
+- `wclp_validation_errors_total` - After validation errors
+
+### Counter resets
+
+Counters persist in WordPress options and survive restarts. To reset:
+
+```php
+\Jeremias\WcLicensedProduct\Metrics\PrometheusController::resetCounters();
+```

src/Metrics/PrometheusController.php

@@ -43,6 +43,29 @@ final class PrometheusController
         }
 
         add_action('wp_prometheus_collect_metrics', [$this, 'collectMetrics']);
+        add_action('wp_prometheus_register_dashboards', [$this, 'registerDashboard']);
+    }
+
+    /**
+     * Register Grafana dashboard with wp-prometheus
+     *
+     * @param object $provider The dashboard provider object
+     */
+    public function registerDashboard(object $provider): void
+    {
+        $dashboardFile = WC_LICENSED_PRODUCT_PLUGIN_DIR . 'docs/grafana-dashboard.json';
+
+        if (!file_exists($dashboardFile)) {
+            return;
+        }
+
+        $provider->register_dashboard('wc-licensed-product', [
+            'title'       => __('WC Licensed Product - License Metrics', 'wc-licensed-product'),
+            'description' => __('Monitor license status, downloads, API usage, and validation errors.', 'wc-licensed-product'),
+            'icon'        => 'dashicons-admin-network',
+            'file'        => $dashboardFile,
+            'plugin'      => 'WC Licensed Product',
+        ]);
     }
 
     /**

wc-licensed-product.php

@@ -3,7 +3,7 @@
  * Plugin Name: WooCommerce Licensed Product
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-licensed-product
  * Description: WooCommerce plugin to sell software products using license keys with domain-based validation.
- * Version: 0.7.4
+ * Version: 0.7.5
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * License: GPL-2.0-or-later
@@ -28,7 +28,7 @@ if (!defined('ABSPATH')) {
 }
 
 // Plugin constants
-define('WC_LICENSED_PRODUCT_VERSION', '0.7.4');
+define('WC_LICENSED_PRODUCT_VERSION', '0.7.5');
 define('WC_LICENSED_PRODUCT_PLUGIN_FILE', __FILE__);
 define('WC_LICENSED_PRODUCT_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('WC_LICENSED_PRODUCT_PLUGIN_URL', plugin_dir_url(__FILE__));