Hooks are the YAML-native way to add cross-cutting behaviour: rate limiting, auto-summarising long tool output, redacting PII, capping cost, audit logging. Each hook declares an event (turn_start, tool_end, error), an optional condition, and an action. Most production patterns are 4-12 lines of YAML. The article linked below walks through seven of them.
Engineering notes from the Digitorn team. No marketing, no launch announcements, no "10 prompts that will change your life". Just the things we write that we'd want to read.