# Developer Setup > TLDR: run `npm install` and `npm start` inside the `nix-shell` for this repository. ## Requirements - Having the [nix-shell installed](https://developer.holochain.org/docs/install/#install-the-nix-package-manager). - Note that you don't have to execute `nix-shell https://holochain.love` as we are going to be building on a custom version of holochain. - Enter the nix-shell on this folder with: ```bash nix-shell . ``` This will take a long time the first time you do it. To verify you have `holochain` and `hc` correctly installed: ```bash holochain --version ``` Should give something like: ```bash holochain 0.0.104 ``` ## Install ```bash npm install ``` ## Running ```bash npm start ``` ## Building ```bash npm run build:happ ``` This should create a `workdir/happ/membrane-invitations-test.happ` file. ## Testing ```bash npm test ```