box-factory-hooks-design

Deterministic hooks run at defined lifecycle points with predictable outcomes. Design them by identifying the lifecycle event, defining a single purpose, validating inputs before tool execution, and ensuring completion within 60 seconds with no user interaction required.

A reliable hook enforces deterministic execution by running at fixed lifecycle points, using explicit workflow selection, validating tool inputs, integrating predictably with the tool chain, and adhering to official specs. This eliminates runtime variability and user interaction.

Use a pre-tool-use hook to validate and transform inputs before tool execution. Other lifecycle hooks serve different purposes: pre-run for initial setup, post-tool-use for output handling, and post-run for cleanup. Match the hook type to your workflow stage.

Validate your hook design using the checklist-driven creation steps: confirm single purpose, verify predictable outcomes at each lifecycle point, ensure sub-60-second runtime, eliminate user interaction, and align with official Claude Code hook specifications.

Yes. Hooks enforce predictable tool integration by validating inputs at defined lifecycle points, using explicit workflow selection, and running deterministically without user interaction. This ensures reliable automation across your tool chain.

Hooks execute at defined lifecycle points: pre-run before execution begins, pre-tool-use before each tool call, post-tool-use after tool completion, and post-run after all execution finishes. Each point enables deterministic decision-making and validation.