diff --git a/CLAUDE.md b/CLAUDE.md
index c027f66..e8fca7c 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -338,7 +338,7 @@ Admin features always work; frontend requires valid license.
 - Implemented license settings page with validation/activation buttons
 - Created admin CSS and JavaScript for license management
 - Created Gitea CI/CD pipeline at `.gitea/workflows/release.yml`
-- Created `PLAN.md` with full implementation roadmap (8 phases)
+- Created `PLAN.md` with full implementation roadmap (9 phases)
 - Created `README.md` with user documentation
 - Created `CHANGELOG.md` following Keep a Changelog format
 - Updated `CLAUDE.md` with architecture details
diff --git a/PLAN.md b/PLAN.md
index 61b3722..da2b0f9 100644
--- a/PLAN.md
+++ b/PLAN.md
@@ -180,6 +180,12 @@ This document outlines the implementation plan for the WP BnB Management plugin.
 - [ ] Guest statistics
 - [ ] Export functionality (CSV, PDF)
 
+## Phase 9: Prometheus Metrics (v0.9.0)
+
+- [ ] Meanigful Metrics for this Plugin, see <https://src.bundespruefstelle.ch/magdev/wp-prometheus/raw/branch/main/README.md> for implementation details
+- [ ] Example Grafana-Dashboard, see <https://src.bundespruefstelle.ch/magdev/wp-prometheus/raw/branch/main/README.md> for implementation details
+- [ ] Update settings page to enable/disable metrics
+
 ## Future Considerations (v1.0.0+)
 
 ### WooCommerce Integration (Optional)
@@ -286,15 +292,16 @@ The plugin will provide extensive hooks for customization:
 
 ## Version Milestones
 
-| Version | Focus           | Target   |
-| ------- | --------------- | -------- |
-| 0.0.1   | Initial setup   | Complete |
-| 0.1.0   | Data structures | Complete |
-| 0.2.0   | Pricing         | Complete |
-| 0.3.0   | Bookings        | Complete |
-| 0.4.0   | Guests          | Complete |
-| 0.5.0   | Services        | Complete |
-| 0.6.0   | Frontend        | Complete |
-| 0.7.0   | CF7 Integration | TBD      |
-| 0.8.0   | Dashboard       | TBD      |
-| 1.0.0   | Stable Release  | TBD      |
+| Version | Focus              | Target   |
+| ------- | ------------------ | -------- |
+| 0.0.1   | Initial setup      | Complete |
+| 0.1.0   | Data structures    | Complete |
+| 0.2.0   | Pricing            | Complete |
+| 0.3.0   | Bookings           | Complete |
+| 0.4.0   | Guests             | Complete |
+| 0.5.0   | Services           | Complete |
+| 0.6.0   | Frontend           | Complete |
+| 0.7.0   | CF7 Integration    | TBD      |
+| 0.8.0   | Dashboard          | TBD      |
+| 0.9.0   | Prometheus Metrics | TBD      |
+| 1.0.0   | Stable Release     | TBD      |