Free WP-CLI Tool: Safe Cornerstone HTML Storage Migration for WPML Sites

Hi everyone,

I’m sharing a small WP-CLI MU plugin I built for migrating Cornerstone content storage on WPML multilingual sites.

The reason for it is that HTML storage migration can be risky on multilingual setups if the render process reuses the wrong language context or cached document state. In that case, a translated post may end up with post_content generated from the source-language post, even if the frontend still appears correct because Cornerstone can rebuild from _cornerstone_data.

This plugin adds a safer CLI migration flow that:

  • switches WPML to the correct post language before rendering
  • clears Cornerstone render/cache state per post
  • validates that generated HTML belongs to the same post being saved
  • refuses to save when the HTML marker points to another post
  • includes dry-run, validation, and repair commands

Repository:

This is not an official Theme.co plugin. Use carefully, test on staging first, and always take a database backup before running it in production.