OpenZeppelin is a library for writing secure Smart Contracts on Ethereum.

With OpenZeppelin, you can build distributed applications, protocols and organizations:

• using common contract security patterns (See Onward with Ethereum Smart Contract Security)
• in the Solidity language.

NOTE: New to smart contract development? Check our introductory guide.

OpenZeppelin integrates with Truffle, an Ethereum development environment. Please install Truffle and initialize your project with truffle init.

npm install -g truffle
mkdir myproject && cd myproject
truffle init

To install the OpenZeppelin library, run the following in your Solidity project root directory:

npm init -y
npm install -E openzeppelin-solidity

Note that OpenZeppelin does not currently follow semantic versioning. You may encounter breaking changes upon a minor version bump. We recommend pinning the version of OpenZeppelin you use, as done by the -E (--save-exact) option.

After that, you'll get all the library's contracts in the node_modules/openzeppelin-solidity/contracts folder. You can use the contracts in the library like so:

import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';

contract MyContract is Ownable {
  ...
}

OpenZeppelin is meant to provide secure, tested and community-audited code, but please use common sense when doing anything that deals with real money! We take no responsibility for your implementation decisions and any security problem you might experience.

If you find a security issue, please email [email protected].

Building a distributed application, protocol or organization with OpenZeppelin?

• Read documentation: https://openzeppelin.org/api/docs/open-zeppelin.html

• Ask for help and follow progress at: https://slack.openzeppelin.org/

Interested in contributing to OpenZeppelin?

• Framework proposal and roadmap: https://medium.com/zeppelin-blog/zeppelin-framework-proposal-and-development-roadmap-fdfa9a3a32ab#.iain47pak
• Issue tracker: https://github.com/OpenZeppelin/openzeppelin-solidity/issues
• Contribution guidelines: https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md
• Wiki: https://github.com/OpenZeppelin/openzeppelin-solidity/wiki

Code released under the MIT License.