API Versions

This document lists the changes made between the different API versions.

Version 3 (>= WordPress 6.3)

• WordPress 6.3 introduced the iframed post editor when all registered blocks use Block API version 3 or higher and no traditional meta boxes are present.
• WordPress 7.0 evaluates the blocks in the post content instead of all registered blocks when deciding whether to use the iframe.
• Gutenberg 23.6 and WordPress 7.1 always use the iframe for the post editor, regardless of the apiVersion of the blocks in the post content.

Adding version 3 support means that a block should work inside an iframe. Refer to the iframe editor migration guide for testing and migration guidance.

Version 2 (>= WordPress 5.6)

• To render the block element wrapper for the block’s edit implementation, the block author must use the useBlockProps() hook.
• The generated class names and styles are no longer added automatically to the saved markup for static blocks when save is processed. To include them, the block author must explicitly use useBlockProps.save() and add to their block wrapper.

Version 1

Initial version.