src/hooks/context.rs

This file holds the payloads your hooks receive, plus the CompactResult steering object a pre-compact hook returns. Read it when you wonder what a hook actually knows at the moment it fires.

Key items

RunStartContext { session_id, model, working_directory } opens your run.

RunEndContext { session_id, reason, total_turns, total_tokens, duration_secs } closes it, and RunEndReason is one of Complete, Cancelled, Error, MaxTurns, or ContextOverflow.

PreToolUseContext { tool_name, input, session_id, turn_number } carries the exact JSON your tool will receive.

PostToolUseContext { tool_name, input, output, is_error, duration_ms, session_id, turn_number } carries what came back.

CompactTrigger { Auto, Manual } maps from From<CompactReason>, where threshold and emergency become Auto and manual stays Manual.

PreCompactContext { trigger, custom_instructions, message_count, tokens_before, context_window, session_id } reaches your hooks in order, so later hooks see earlier hooks’ instructions accumulated.

PostCompactContext { trigger, messages_compacted, tokens_saved, tokens_after, duration_ms, session_id } reports what the pass achieved.

Behavior notes

Your executor chains pre-compact results. The first abort wins and skips the remaining hooks, new_instructions is last-writer-wins, and additional_context accumulates, so the merged guidance genuinely reaches your compactor.

Deep dive: Hooks.