Build custom Gutenberg blocks with your AI agent

WP MCP already lets your AI agent use any registered Gutenberg block. Now it can also create new block types from a description, safely: a block is a data spec, never generated PHP.

What you need

• WP MCP installed and connected to your AI client, with its Pro tier active.
• The block editor (Gutenberg), which every modern WordPress site has.

How a custom block is defined

A block is a spec with three parts:

• Attributes, the editable fields (string, rich text, URL, image, number, boolean, color). Ask list-block-control-types for the full list.
• A template, HTML with {{attribute_name}} placeholders.
• Metadata, a title and category.

› Make a "callout" block with a heading, a rich-text body, and a link.

create-custom-block validates the spec, stores it, and registers it under the wpmcp/ namespace with register_block_type, so it appears in the inserter. validate-block-spec checks a spec first without storing it.

Safe by design: no code generation, no eval

A custom block is interpreted data, not generated code. A single render callback renders every block by substituting your attribute values into the template, escaping each by its type: plain text is escaped, rich text is filtered with wp_kses_post, and URLs go through esc_url. There is no eval anywhere, so a stored block can never execute arbitrary code.

Manage your blocks

› List my custom blocks.
› Update the callout block's default heading.
› Disable the seasonal-banner block after the sale.

list-custom-blocks, update-custom-block, set-block-status, and delete-custom-block manage the set. Blocks are stored as ordinary posts, so disabling or deleting one is reversible.