Ethereum Cookbook

How to do it…

1. Openzeppelin is distributed through npm. Install it using the npm install command:

npm install -E openzeppelin-solidity

npm does an automatic semantic version update for improved security and bug fixes while installing. This is not suggested for openzeppelin, since minor changes in a contract can make it work differently. To avoid semantic version updates, use --save-exact or the -E attribute while installing.

2. The files will be downloaded to the node_modules folder. Reference them directly by specifying the contract's file path:

import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';contract NewContract is Ownable {  // ...}

3. Since solidity allows references from GitHub, you can also import the library directly from ...