Is it possible to modify/install tools on nektos/act runner image?

[pparh602]

I have downloaded the medium size runner image (around 500-1.2 GB). Now, I want to install some tools on that image such as npm, maven and other tools, so my running speed will be reduce, since currently the image will be downloading all the necessary packages from scratch. so the whole process to run git action take around 12-14 minutes out of which only 3 minutes required to run my Git Actions rest of the time goes to downloading various packages and tools.

[KnisterPeter]

You can run act with any image you prepared on your side, so yes you can preinstall all your requirements.
Have a look at our docs here: https://github.com/nektos/act#runners