Hooks Validator

Validate hooks configuration in .claude/settings.json and hook scripts against the official Claude Code spec.

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Validation Steps

1. Check settings.json

Verify the hooks section exists and is valid.

2. Validate Hook Event Names

Claude Code defines 30 hook events. Accept any of them; flag unknown names with a typo hint (e.g. PrePromptSubmit -> UserPromptSubmit, PostToolBatchFailure -> PostToolBatch, SubagentStarts -> SubagentStart).

Group	Events
Lifecycle	SessionStart, SessionEnd, Setup
Prompt	UserPromptSubmit, UserPromptExpansion
Tool	PreToolUse, PostToolUse, PostToolUseFailure, PostToolBatch
Permission	PermissionRequest, PermissionDenied
Subagent	SubagentStart, SubagentStop
Stop	Stop, StopFailure
Task	TaskCreated, TaskCompleted
Compaction	PreCompact, PostCompact
Notification	Notification, MessageDisplay
MCP elicitation	Elicitation, ElicitationResult
Environment	ConfigChange, CwdChanged, FileChanged, InstructionsLoaded, WorktreeCreate, WorktreeRemove, TeammateIdle

That is all 30 events. See the official hooks docs for each event's payload.

3. Validate Each Hook Entry

• type is one of: command, prompt, http, mcp_tool, agent (default command)
• If type: command: command path exists and script is executable
• If type: prompt: prompt string is non-empty
• matcher is a string if present (tool events: tool name, regex, or *)
• timeout is a positive integer if present (default: 60s per hook)
• once is boolean if present
• if / statusMessage are strings if present

4. Validate Hook Scripts

• File exists and is executable
• Has an appropriate shebang
• If the script emits structured output on stdout, it is valid JSON. Silent / exit-code-only hooks are valid — no stdout is required (exit 0 = allow/continue, exit 2 = block for PreToolUse).

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Decision Output Schema

When a script does emit JSON, validate it against the event contract:

• PreToolUse: hookSpecificOutput.permissionDecision is allow, deny, or ask. The legacy top-level {"decision": "approve" | "block"} is still accepted.
• Stop / SubagentStop: continuation uses {"decision": "block", "reason": "<next prompt>"} — the key is reason.
• Input JSON always carries the event under hook_event_name (not hook_type).

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Output Format

## Hooks Validation Report

### Configuration Status: VALID / INVALID

### Configured Hooks
| Event | Matcher | Script | Status |
|-------|---------|--------|--------|
| Stop | * | auto-loop-stop.sh | OK |

### Script Validation
| Script | Exists | Executable | Output |
|--------|--------|------------|--------|
| auto-loop-stop.sh | OK | OK | JSON OK / silent |

### Issues Found
1. [Issue and fix]

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Auto-Fix

• Make scripts executable
• Add missing shebang
• Create missing hook scripts
• Correct a misspelled event name to the nearest valid event
• Normalize hook_type -> hook_event_name in emitted JSON