[jothimani-rajendran]

What this changes

hook_config() for antigravity now writes Stop's handler bare ({"type": "command", "command": ...}) instead of inside a {"hooks": [...]} group, and gives every PreToolUse/PostToolUse group a matcher ("*" when the caller passes none). A maintainer's Antigravity IDE log (2026-10-17) rejected the old file with invalid hook "agentseam": command hook must specify 'command', so none of its hooks loaded.

Before:

{"agentseam": {"PreToolUse": [{"hooks": [{"type": "command", "command": "guard"}]}],
               "Stop":       [{"hooks": [{"type": "command", "command": "guard"}]}]}}

After:

{"agentseam": {"PreToolUse": [{"matcher": "*", "hooks": [{"type": "command", "command": "guard"}]}],
               "Stop":       [{"type": "command", "command": "guard"}]}}

Claim check

• No capability claim is widened without a mechanism behind it. Block, rewrite and fail-mode claims are unchanged. Basis stays vendor-docs, and nothing is marked witnessed.
• Any changed MATRIX row carries a verified record. Only the antigravity row's notes change: they record the corrected shape, the observed rejection, and that the corrected file has not been run.
• Primary source: https://antigravity.google/docs/hooks (read 2026-10-17), "Schema and file format":
  • "The hooks.json file maps hook names to their event configurations". The example gives PreToolUse/PostToolUse {matcher, hooks} groups. It gives PreInvocation and SessionStart bare {"type": "command", "command": ...} items.
  • The Supported events table marks Stop as "N/A (matcher ignored)", the same as PreInvocation/SessionStart. The docs give no explicit Stop example, so treating Stop as bare is inferred from that class, and the observed log error supports it.
  • Matcher: "\"\" or \"*\": Match all tools."
  • Hook handler configuration: "command | string | Required."

Checks

• pytest -q passes (2617 passed, 6 skipped, local)
• ruff check . and ruff format --check . pass
• Runtime path is still stdlib-only
• Commits are signed off (git commit -s)

Notes for the reviewer

• New hook_entry.flat_events field (schema + recount derive it from the golden fixture). default_match now also applies to the hooks_map wrapper; only antigravity sets either field, and the other vendors' golden fixtures are byte-identical.
• The "*" default matcher is a deviation beyond the minimum fix. Every grouped example in the docs carries a matcher. If Antigravity tells grouped entries from bare ones by the matcher key, a group without one would hit the same error. "*" is documented to match all tools.
• Not run against Antigravity. AGY-2 (chock) re-emits and the owner re-runs the witness.

---

Generated by Claude Code