PreToolUse hook reports error but doesn't block Bash tool execution
Description
PreToolUse hooks for the Bash tool report errors but don't actually prevent the tool from executing. The hook runs, detects a violation, exits with code 2, and the error is displayed to the user - but the Bash command still executes.
Steps to Reproduce
- Configure a PreToolUse hook for Bash in
~/.claude/settings.json:
{
"PreToolUse": [
{
"matcher": "Bash",
"hooks": [
{
"type": "command",
"command": "if echo \"$INPUT\" | jq -e '.tool_input.command | test(\"git push\")' > /dev/null; then echo '❌ BLOCKED: git push commands are forbidden.' >&2; exit 2; fi"
}
]
}
]
}
- Run a Bash tool with
git push
- Observe: "PreToolUse:Bash hook error" is displayed
- Bug: The git push command still executes successfully
Expected Behavior
When a PreToolUse hook exits with a non-zero code (especially exit 2), the tool execution should be blocked/cancelled.
Actual Behavior
The hook error is reported but the Bash command executes anyway:
⏺ Bash(git push)
⎿ PreToolUse:Bash hook error
⎿ To https://github.com/...
abc123..def456 main -> main
Impact
PreToolUse hooks cannot actually prevent dangerous operations like:
- Pushing to remote repositories without review
- Running destructive commands
- Bypassing safety checks
Environment
- Claude Code CLI
- Hook type: PreToolUse with Bash matcher
- Hook exit code: 2
PreToolUse hook reports error but doesn't block Bash tool execution
Description
PreToolUse hooks for the Bash tool report errors but don't actually prevent the tool from executing. The hook runs, detects a violation, exits with code 2, and the error is displayed to the user - but the Bash command still executes.
Steps to Reproduce
~/.claude/settings.json:{ "PreToolUse": [ { "matcher": "Bash", "hooks": [ { "type": "command", "command": "if echo \"$INPUT\" | jq -e '.tool_input.command | test(\"git push\")' > /dev/null; then echo '❌ BLOCKED: git push commands are forbidden.' >&2; exit 2; fi" } ] } ] }git pushExpected Behavior
When a PreToolUse hook exits with a non-zero code (especially exit 2), the tool execution should be blocked/cancelled.
Actual Behavior
The hook error is reported but the Bash command executes anyway:
Impact
PreToolUse hooks cannot actually prevent dangerous operations like:
Environment