SessionStart API

Available when inheriting from ClaudeHooks::SessionStart:

Input Helpers

Input helpers to access the data provided by Claude Code through STDIN.

📚 Shared input helpers

Method	Description
source	Get the session start source: 'startup', 'resume', 'clear', or 'compact'

Hook State Helpers

Hook state methods are helpers to modify the hook's internal state (output_data) before yielding back to Claude Code.

📚 Shared hook state methods

Method	Description
add_additional_context!(context)	Add contextual information for Claude's session
add_context!(context)	Alias for add_additional_context!
empty_additional_context!	Clear additional context

Output Helpers

Output helpers provide access to the hook's output data and helper methods for working with the output state.

📚 Shared output helpers

Method	Description
output.additional_context	Get the additional context that was added

Hook Exit Codes

Exit Code	Behavior
exit 0	Operation continues STDOUT added as context to Claude
exit 1	Non-blocking error STDERR shown to user
exit 2	N/A STDERR shown to user only