UserPromptExpansion

A Claude Code hook event, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.

What it is

Presence across releases

The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.

Changelog entries naming it

1. v2.1.248New hook events and compiled-in plugin admission defaults

   Three new hook event names appear, and unverified plugins are still allowed to load.

   named in this entry

2. v2.1.238Prompt-expansion hooks can hide the original prompt from a block message

   Prompt-expansion hooks can keep your original prompt text out of the block message.

   named in this entry

Documentation pages

• Hooks reference reference table Claude Code CLI
• Intercept and control agent behavior with hooks reference table Claude Code CLI
• Agent SDK reference - TypeScript mentions it Claude Code CLI
• Automate actions with hooks mentions it Claude Code CLI
• Plugins reference mentions it Claude Code CLI

A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.

Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the hook event does. All hook events.