LEAN Engine Versions


The latest master branch on the LEAN GitHub repository is the default engine branch that runs the backtesting, research, and live trading nodes in QuantConnect Cloud. The latest version of LEAN is generally the safest as it includes all bug fixes.

Trading Firm or Institution tier users concerned for stability can elect to use older or custom versions of LEAN in the IDE. These are powered by the QuantConnect/LEAN Github Branches. We use a continuous deployment process to ship custom branches to production for trading. To create a custom version of LEAN, make a pull request to LEAN which will be reviewed by our team.

Change Branches

Follow these steps to change the LEAN engine branch that runs your backtests and live trading algorithms:

  1. Open a project.
  2. In the Project panel, click the LEAN Engine field and then click a branch from the drop-down menu.
  3. (Optional) Click About Version to display the branch description.
  4. If you want to always use the master branch, select the Always use Master Branch check box.
  5. Click Select.

Changing the Lean engine branch only affects the current project. If you create a new project, the new project will use the master branch by default.

Request New Branches

Before starting a pull-request to create a new branch, contact us to discuss the goals of the project.

You can also see our Videos. You can also get in touch with us via Discord.

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