I'm a developer looking to understand Composer's versioning and core functionalities. From the download page, what is the SHA256 checksum for Composer version 1.2.1, and where can I find its changelog? After that, navigate to the main documentation and identify the command used to install project dependencies from a `composer.json` file.
Navigate to 'getcomposer.org'. Click on the 'Download' link in the navigation menu. Locate 'Download version 1.2.1' and extract its SHA256 checksum. Click on the 'Changelog for version 1.2.1' link to navigate to its changelog. Confirm the changelog page loads successfully, then navigate back to the main site or home page. Click on the 'Documentation' link in the navigation menu. On the documentation page, find and extract the command used to install project dependencies from a `composer.json` file.
The agent successfully navigates to the 'Download' page. The SHA256 checksum for version 1.2.1 is stated as 'c2e04040b807a8530e5c83de56bdaaf63a0f183f8fd449bbe6e41f660e647427'. The agent successfully navigates to the changelog page for version 1.2.1. The agent successfully navigates to the 'Documentation' page. The command for installing project dependencies from a `composer.json` file is identified as 'composer install'.