# Developing MainNet library
Download and install dependencies.
git clone https://github.com/mainnet-cash/mainnet-js.git
cd mainnet-js
yarn install
yarn build # build the mainnet library
yarn api:serve:install # install the library on the express server
Run the server in single threaded mode:
yarn api:serve
or in cluster mode:
PORT=3000 WORKERS=5 yarn api:serve:cluster
On MacOS if you get gyp: No Xcode or CLT version detected!
you might want to follow
this article (opens new window).