Running Psalm

Once you've set up your config file, you can run Psalm from your project's root directory with


and Psalm will scan all files in the project referenced by <projectFiles>.

If you want to run on specific files, use

./vendor/bin/psalm file1.php [file2.php...]

Command-line options

Run with --help to see a list of options that Psalm supports.

Exit status

Psalm exits with status 0 when it successfully completed and found no issues, 1 when there was a problem running Psalm and 2 when it completed successfully but found some issues. Any exit status apart from those indicate some internal problem.


Psalm currently offers some GitHub integration with public projects.

Add --shepherd to send information about your build to

Currently, Shepherd tracks type coverage (the percentage of types Psalm can infer) on master branches.

Running Psalm faster

Psalm has a couple of command-line options that will result in faster builds:

  • --threads=[n] to run Psalm’s analysis in a number of threads
  • --diff which only checks files you’ve updated since the last run (and their dependents).

In Psalm 4 --diff is turned on by default (you can disable it with --no-diff).

Data from the last run is stored in the cache directory, which may be set in configuration. If you are running Psalm on a build server, you may want to configure the server to ensure that the cache directory is preserved between runs.

Running them together (e.g. --threads=8 --diff) will result in the fastest possible Psalm run.