Prometheus Has a Free API — Monitor Everything with PromQL

TL;DR Prometheus is the industry-standard open-source monitoring system. It collects metrics from your applications via a pull model, stores them in a time-series database, and provides PromQL for powerful querying — all completely free. What Is Prometheus? Prometheus is a CNCF graduated project for monitoring: Pull-based — scrapes metrics from HTTP endpoints Time-series DB — efficient storage with compression PromQL — powerful query language for metrics Alerting — built-in alertmanager for notifications Service discovery — auto-find targets in Kubernetes, Docker, EC2 Free — Apache 2.0, self-hosted Quick Start # prometheus.yml global : scrape_interval : 15s scrape_configs : - job_name : " my-app" static_configs : - targets : [ " localhost:8080" ] - job_name : " node-exporter" static_configs : - targets : [ " localhost:9100" ] # Run with Docker docker run -p 9090:9090 \ -v ./prometheus.yml:/etc/prometheus/prometheus.yml \ prom/prometheus # Access UI at http://localhost:9090 Instrumentin