- Add prom-client ^15.1.3 as production dependency
- Migrate Counter class to use prom-client internally
- Migrate Gauge class to use prom-client internally
- Migrate Histogram class to use prom-client internally
- Update getMetricsOutput() to use prom-client's native metrics()
- Update contentType() to use prom-client's contentType
- Enable collectDefaultMetrics() for Node.js system metrics
- Maintain backward compatibility with existing API
Benefits:
- Native OpenMetrics format export
- Proper histogram bucket handling
- Default Node.js metrics (memory, CPU, event loop, GC)
- Better integration with Grafana/Prometheus ecosystem
Claude