NSClient++¶
A simple, powerful, and secure monitoring agent for Windows and Linux. Works with Nagios, Icinga, Op5, Prometheus, check_mk — and anything that speaks NRPE, NSCA, NRDP, or REST.
Why NSClient++¶
- Cross-platform — Windows and major Linux distros (details)
- Many protocols — NRPE, NSCA, NSCA-NG, NRDP, check_mk, Icinga 2, Op5, Graphite, Syslog, SMTP, REST, Prometheus/OpenMetrics
- Web UI with live dashboards and check explorer
- Scriptable in Python, Lua, or any external script
- Command line client — check_nsclient drives local and remote agents from a single binary
- Secure by default — TLS, client certs, allowed-hosts

Latest news¶
Nagios World Conference 2026 wrapped up in the Twin Cities today, so first of all: thank you. To everyone who came to my two sessions, asked questions, or said hi.
0.20.0 brings back .NET plugins — on Linux as well as Windows this time — and lets the WEB server hold on to passive check results so a monitoring server can collect a host's scheduled checks in a…
0.19.0 gives the interactive console a proper prompt — line editing, history, tab completion and highlighting — and fixes a heap-corruption crash that took the whole agent down whenever a…
All news All releases on GitHub
Get started¶
- Quick Start — 10-minute walkthrough
- Installation guide — MSI options & silent install
- All downloads — agent, command line client, web UI bundle
- Securing the agent — TLS & client certs
- Web Interface
Documentation¶
- Monitoring scenarios — common real-world setups
- Reference — every module & command
- Concepts — how it works under the hood
- check_nsclient — the standalone command line client
- FAQ