From a326d21ede3a7a0ba3a5049ec43860950fd2b042 Mon Sep 17 00:00:00 2001
From: Pablo LION <dev@pablolion.com>
Date: Wed, 25 Feb 2026 10:32:21 +0100
Subject: [PATCH] fix(claude_code): wrap hook output in hookSpecificOutput
 envelope
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Claude Code's PreToolUse hook protocol requires responses wrapped in
{"hookSpecificOutput": {"hookEventName": "PreToolUse", "permissionDecision": ...}}.
The previous implementation output permissionDecision at the top level, which
Claude Code silently ignores — making all gait verdicts (allow, deny, ask)
unenforceable regardless of policy.

Fix wraps both emit_response() and the inline emit() function in the required
envelope. Verified against Claude Code v2.1.47–v2.1.49 with all three verdict
paths (allow, require_approval, block) in live interactive sessions.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
---
 CHANGELOG.md                                   |  7 +++++++
 examples/integrations/claude_code/gait-gate.sh | 14 ++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75ee695a..d6293557 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 - _No unreleased entries yet._
 
+### Fixed
+
+- Fixed Claude Code hook integration (`gait-gate.sh`) to wrap hook responses in
+  the `hookSpecificOutput` envelope required by Claude Code's PreToolUse
+  protocol. Without this wrapper, Claude Code silently ignores hook responses,
+  making all gait verdicts (allow, deny, ask) unenforceable.
+
 ### Changed
 
 - Gate intent normalization now treats omitted target `discovery_method` as `unknown` instead of empty so policies can deterministically match unknown/dynamic discovery paths.
diff --git a/examples/integrations/claude_code/gait-gate.sh b/examples/integrations/claude_code/gait-gate.sh
index 795bd7b9..b5f73d64 100755
--- a/examples/integrations/claude_code/gait-gate.sh
+++ b/examples/integrations/claude_code/gait-gate.sh
@@ -16,14 +16,15 @@ emit_response() {
 import json
 import os
 
-payload = {
+inner = {
+    "hookEventName": "PreToolUse",
     "permissionDecision": os.environ["DECISION"],
     "permissionDecisionReason": os.environ["REASON"],
 }
 trace_path = os.environ.get("TRACE_PATH", "").strip()
 if trace_path:
-    payload["tracePath"] = trace_path
-print(json.dumps(payload))
+    inner["tracePath"] = trace_path
+print(json.dumps({"hookSpecificOutput": inner}))
 PY
 }
 
@@ -60,13 +61,14 @@ strict_mode = os.environ.get("STRICT_MODE", "0").strip().lower() in {"1", "true"
 trace_path = os.environ.get("TRACE_PATH", "").strip()
 
 def emit(decision: str, reason: str) -> None:
-    payload = {
+    inner = {
+        "hookEventName": "PreToolUse",
         "permissionDecision": decision,
         "permissionDecisionReason": reason,
     }
     if trace_path:
-        payload["tracePath"] = trace_path
-    print(json.dumps(payload))
+        inner["tracePath"] = trace_path
+    print(json.dumps({"hookSpecificOutput": inner}))
 
 try:
     decoded = json.loads(proxy_output) if proxy_output.strip() else {}