WordPress / API Reference

`theme_set_custom_css`

Tool tool. Set WordPress core Additional CSS — applies site-wide without editing any theme file

This is a read-only tool: it returns theme set custom css for your WordPress account. It changes nothing.

Ask Claude

You do not call this tool yourself. Ask for the outcome and the client picks the tool:

Theme set custom css in my WordPress account for [css].

It takes 1 required and 1 optional parameter.

Parameters

Parameter	Type	Required	Description
`css`	string	Yes	Css
`append`	boolean	No	Append

Related WordPress tools

theme_set_background
theme_set_header
theme_set_mod
theme_set_site_identity

Before you can call it

This tool needs a connected WordPress account. The WordPress connect guide covers how to authorize it and what it unlocks, and the quickstart gets a client talking to the server in about five minutes.

Start free — 30 tool calls a month

No card required. Connect Google Ads, Meta Ads, GA4 or Search Console and ask Claude for the outcome — it picks the tool.