This is the v2.4.0 release of PyFstat, a python package for gravitational-wave data analysis with the F-statistic, dated 19/08/2026. This release supports python 3.10 to 3.13 (python 3.9 support has been dropped since v2.3). From the changelog: Dropped python 3.9 support. Full support for F3 and higher spin-downs through signal_parameters dictionaries in Writer and derived classes. Flexible parameters dictionary suppport also in search classes. Improved error checking on MCMC prior bounds. Fixed numerical overflow problems in plot_spectrogram(). Fixed MCMCGlitchSearch cumulative 2F plot to include F1 glitch steps. Migrated past of the test suite to pytest fixtures. Updated documentation build and other github integrations. For a list of known issues, or to report any problems, please see: https://github.com/PyFstat/PyFstat/issues