Five monitoring systems should not mean five places to look when something breaks at 3 a.m. Alerta is an open-source alert management server that consolidates alerts from many sources into a single stream, de-duplicates repeats, correlates severity changes, and shows only the current state of each problem in a web console built for fast scanning. Prometheus, Zabbix, Nagios, InfluxDB Kapacitor, cloud watch alarms, and your own scripts all post into the same HTTP API, which accepts a flexible alert format carrying environment, resource, event, severity, and custom attributes, so no tool has to contort itself into someone else's schema first. Repeats of a known fault raise a duplicate count instead of generating another page, and a severity change updates the existing alert rather than birthing a twin. Operators acknowledge problems, assign them, silence expected fire during blackout periods set for maintenance windows, and partition visibility by customer for teams that monitor other people's infrastructure. A command-line client, query language, webhooks, and plugin hooks carry alerts onward into tickets, chat, and paging workflows, and everything persists in MongoDB or PostgreSQL with API keys and OAuth protecting access. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.