Welcome to the nearcore development guide!

The target audience of this guide are developers of nearcore itself. If you are a user of NEAR (either a contract developer, or validator running a node), please refer to the user docs at

This guide is built with mdBook from sources in the nearcore repository. You can edit it by pressing the "edit" icon in the top right corner, we welcome all contributions. The guide is hosted at

The guide is organized as a collection of loosely coupled chapters -- you don't need to read them in order, feel free to peruse the TOC, and focus on the interesting bits. The chapters are classified into three parts:

  • Architecture talks about how the code works. So, for example, if you are interested in how a transaction flows through the system, look there!
  • Practices describe, broadly, how we write code. For example, if you want to learn about code style, issue tracking, or debugging performance problems, this is the chapter for you.
  • Finally, the Misc part holds various assorted bits and pieces. We are trying to bias ourselves towards writing more docs, so, if you want to document something and it doesn't cleanly map to a category above, just put it in misc!

If you are unsure, start with Architecture Overview and then read Run a Node