NSSM runs any application as a Windows Service and restarts it when it exits unexpectedly — similar to srvany / cygrunsrv, but without the suck. It includes a GUI installer and a full CLI.

This tree continues from upstream NSSM 2.24 (2014-08-31, public domain). The first modernized release is 2.25 (Visual Studio 2026 / MSVC v145, standardized layout).

Maintainer: Tuyn Doan

nssm/
├── README.md            # this file
├── CHANGELOG.md         # history + roadmap (Keep a Changelog)
├── build.cmd            # Release build script (VS 2026 / v145)
├── pack.cmd             # package win32+win64 into dist/nssm-<ver>.zip + SHA256
├── VERSION              # version string (edit to bump; git tag overrides)
├── dist/                # packaged artifacts (git-ignored; publish via Releases)
├── nssm.sln             # VS 2008 solution (reference until 2.26)
├── nssm.vcproj          # VS 2008 project (reference until 2.26)
├── src/                 # C++ sources grouped by responsibility
│   ├── include/         #   umbrella header (nssm.h)
│   ├── cli/             #   entry point & command dispatch (nssm.cpp)
│   ├── service/         #   service host, process, hooks, accounts
│   ├── config/          #   registry & settings mapping
│   ├── io/              #   I/O redirect, rotation, event log
│   ├── gui/             #   install/edit dialog (+ resource.h)
│   ├── platform/        #   imports, utf8, env, console
│   ├── resources/       #   nssm.rc, nssm.ico, messages.mc, version.cmd
│   └── gen/             #   generated by build (git-ignored): messages.*, version.h
├── build/               # build output (git-ignored): build/tmp, build/out
└── docs/
    ├── manual.txt       # full usage manual (upstream)
    ├── roadmap/         # interactive roadmap/backlog (index.html)
    └── release/2.25/    # release notes for 2.25 (index.html)

Requires Visual Studio 2026 Build Tools with the Desktop development with C++ workload (toolset v145, MSVC 14.5x). Older installs (e.g. VS 2022 / v143) also work via vswhere.

:: 32-bit (default)
build.cmd

:: 64-bit
build.cmd x64

Output: build\out\x86\nssm.exe or build\out\x64\nssm.exe.

Quick check:

build\out\x86\nssm.exe version

The version string comes from the VERSION file at the repo root (e.g. 2.25). To change it, just edit that file and rebuild — no git required:

2.26

If git is available and the repo has tags, git describe --tags overrides the file (so CI/tagged builds report the exact tag). Without git/tags, the VERSION file value is used; if the file is missing too, it falls back to 0.0.

build.cmd locates Visual Studio via vswhere, loads the MSVC environment, generates version.h (version.cmd), compiles messages.mc, nssm.rc, all *.cpp, and links the required Windows libraries. Generated files (version.h, messages.h/.rc, *.bin) are not committed (see .gitignore).

Sources are grouped into cli/, service/, config/, io/, gui/, and platform/; the umbrella header lives in include/nssm.h. Build inputs are in resources/; generated files go to src/gen/ (git-ignored). Legacy nssm.sln / nssm.vcproj sit at the repo root (standard Visual Studio layout) and are reference-only until the 2.26 MSBuild migration.

Note: the project is still nssm.vcproj (VS 2008 format) at the repo root, so MSBuild cannot build directly — use build.cmd. Migration to nssm.vcxproj is planned for 2.26 (see roadmap).

To produce a release archive, run:

pack.cmd

This builds both platforms (if needed) and writes dist\nssm-<version>.zip plus a .sha256 checksum. The zip mirrors the upstream layout (nssm-<version>\win32\nssm.exe, win64\nssm.exe, README.txt). dist/ is git-ignored — publish the archive via a GitHub Release rather than committing binaries.

Full syntax is in docs/manual.txt. Quick examples:

nssm install <service> <application> [args]
nssm edit    <service>
nssm start   <service>
nssm stop    <service>
nssm remove  <service> confirm

The docs/ folder is published with GitHub Pages as a single-page hub at https://tuyndoan.github.io/nssm/ — one page, four tabs (no page reloads):

• Overview — intro, quick start, navigation.
• Release — release notes rendered inline from docs/release/<x.y.z>/release-data.js.
• Roadmap — backlog/progress rendered inline from docs/roadmap/roadmap-data.js.
• Download — latest binaries pulled live from the GitHub Releases API (with a direct-link fallback).

Other references:

• Changelog: CHANGELOG.md
• Full manual: docs/manual.txt · online
• Standalone interactive pages remain at docs/release/<x.y.z>/ and docs/roadmap/ (also the source of the inline data).

To enable Pages: repo Settings → Pages → Source: GitHub Actions (the pages workflow deploys docs/ on every push to main).

NSSM is public domain. You may use it and/or its source code for any purpose. Original author: Iain Patterson and contributors (2003–2014).