# Python testing | |
To define a host-side python test that can be run by `fx`, CI and CQ: | |
* Use the [python_host_test](/build/python/python_host_test.gni) GN template. | |
* Ensure some `group("tests")` depends on the `python_host_test` rule, | |
and specify the `($host_toolchain)` in the dependency. | |
[Here](/sdk/ctf/build/scripts/BUILD.gn) is an example BUILD.gn. |