Re-verified all fifteen provider hook contracts against first-party
documentation on 2026-07-21; thirteen match exactly.
Letta: the harness-hook page moved to /reference/deprecated/hooks and
is vendor-deprecated in favor of Mods. The shipped contract remains
live and functional; record the current URL and the documented
PostToolUseFailure event the SDK adapters already register.
Grok: xAI documents the hook stdin payload non-exhaustively with only
hookEventName, sessionId, cwd, workspaceRoot, toolName, and toolInput.
Drop the recorded toolUseId/toolResult field claims, which appear
nowhere in official documentation.
ZacharyZhang-NY
060a072f1f