When documentation is silent, measure
Lesson 6 of six in Claude Code Field Notes: Running AI Coding Agents in Production, drawn from operating more than twenty live software surfaces with Claude Code.
Documentation for agent tooling ages faster than it is written. Rather than guessing at a payload shape, capture one. A hook that dumps its input to disk answers the question in a minute, for the exact version you are running:
#!/bin/bash
payload=$(cat)
printf '%s\n' "$payload" >> /tmp/probe/events.jsonl
exit 0Point every event you care about at that script, run one throwaway session, and read the log. Doing this surfaced a documented event whose handler-type table omitted it, even though a handler on that event demonstrably fires. The installed binary is the source of truth. Documentation is a secondary source, and version-gated features make it a moving one.