Available when inheriting from ClaudeHooks::UserPromptExpansion:
Runs when a slash command or other prompt-expansion mechanism is triggered. Can block the expansion.
📚 Shared input helpers
| Method | Description |
|---|
expansion_type | Type of expansion (e.g. 'slash_command') |
command_name | The command name (without the /) |
command_args | The arguments passed to the command |
command_source | Where the command was defined ('user', 'project', etc.) |
prompt | The expanded prompt text |
📚 Shared hook state methods
| Method | Description |
|---|
block!(reason) | Block the expansion with a reason |
add_additional_context!(context) | Add additional context visible to Claude |
📚 Shared output helpers
| Method | Description |
|---|
output.blocked? | Check if the expansion was blocked |
output.decision | Get the decision ('block' or nil) |
output.reason | Get the block reason |
| Exit Code | Behavior |
|---|
exit 0 | Expansion proceeds |
exit 2 | Blocks the expansion; STDERR shown to Claude |