# itay-grudev/SingleApplication

Replacement of QtSingleApplication for Qt 5 and Qt 6 with support for inter-instance communication.

Repository: https://github.com/itay-grudev/SingleApplication
Canonical: https://ross.abutalabs.com/products/singleapplication
Homepage: https://itay-grudev.github.io/SingleApplication/
Language: C++
License: NOASSERTION
License Family: other
Topics: c-plus-plus, qt, qt5, singleton, application, qtsingleapplication, singleapplication, subsequent-instances, cpp, hacktoberfest, qt6
Last push: 2026-06-16T20:10:35+00:00

## Health v2 (maintenance only)
Score: 82/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 87, release rhythm 65, longevity 100
- inputs: {"age_days": 5002, "days_push": 78, "days_rel": 78, "gap_med": 131.5, "n_releases_24m": 5}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1005, forks 245 (observed 2026-09-03T02:15:12.959704+00:00)

## What it is
A C++ library replacing QtSingleApplication for Qt 5 and Qt 6 that enforces single-instance behavior for Qt applications. It supports inter-instance communication, allowing secondary instances to send data to the primary instance.

## Use cases
- prevent multiple instances of my qt application from running
- send command-line arguments from a second app launch to the running instance
- replace qtsingleapplication in a qt6 project
- single instance desktop app with inter-instance communication
- focus the existing window when user launches the app again

## When to choose
- you are building a Qt 5 or Qt 6 desktop application that must run as a single instance
- you need subsequent launches to forward data or arguments to the primary instance
- you want a drop-in QApplication/QCoreApplication replacement with qmake or CMake integration

## When to avoid
- your application is not built with Qt
- you need single-instance enforcement outside of the Qt application lifecycle
- you require a permissive license - the project uses a custom license

## Facets
- artifact type: library
- maturity: active
- function: concurrency, developer-tools
- domain: desktop-applications, cross-platform, developer-tools
- platform: cpp, cross-platform
- tags: qt, qt5, qt6, single-instance, ipc, singleton, desktop

## Member repositories
- itay-grudev/SingleApplication (main) score 82

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:12.959704+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:14:00.498316+00:00, confidence not recorded.
  - readme: https://github.com/itay-grudev/SingleApplication (fetched 2026-09-03T02:15:12.959704+00:00, sha 6027e01cef41)
  - homepage: https://itay-grudev.github.io/SingleApplication/ (fetched 2026-08-29T13:13:49.277770+00:00, sha d257a6da8317)
- Data as of 2026-08-30T08:39:29.467469+00:00.