Adding BLT to an existing project


Acquia will end support for BLT on December 31, 2024. For more information on how to replace your BLT implementation with updated functionality, see You don’t need BLT on Acquia Cloud.


  • You can add BLT versions 12 and later to third-party Drupal distributions and existing applications. Older versions of BLT are no longer supported and must not be used.


  • The Drupal root must be in a top-level docroot directory.

  • You must already use Composer to manage website dependencies. If you don’t, see Using Composer to manage Drupal website dependencies and change your project accordingly.

  • Be sure your dependencies are up-to-date by executing the command: composer update, and the dependencies don’t break your project.


To add BLT to a pre-existing Drupal project:

  1. At the command prompt, change to your existing project directory with the cd command.

  2. To configure Composer’s minimum-stability and prefer-stable values, run:

    composer config minimum-stability dev
    composer config prefer-stable true
  3. To install BLT by using Composer, run:

    composer require acquia/blt:^13


    There might be conflicting Composer dependencies. You must review any Composer warnings or errors prior to continuing.

  4. Review all new and modified files and commit them to Git. BLT places new files in your project directory.

  5. Run BLT commands by using vendor/bin/blt. To run BLT commands without specifying the full binary path, install the BLT Launcher.

  6. Run blt doctor to diagnose any potential remaining issues requiring manual intervention.

For information about common instructions and how to begin using BLT, see Next steps with BLT.