# Hook Diagnostics

Diagnose Claude Code hook installation, delivery, and ingestion issues.

- Repository: https://github.com/hoangsonww/Claude-Code-Agent-Monitor (1136 stars)
- Category: AI and agents
- License: MIT
- Last updated: 2026-10-31
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill hook-diagnostics -g -a claude-code -y`
Codex: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill hook-diagnostics -g -a codex -y`
Cursor: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill hook-diagnostics -g -a cursor -y`
Gemini CLI: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill hook-diagnostics -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add hoangsonww/Claude-Code-Agent-Monitor`

## Description

Diagnose Claude Code hook installation, delivery, and ingestion issues. Checks hook configuration, connectivity, event flow, and identifies common problems. Use when events are not appearing in the dashboard.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Hook Diagnostics

Diagnose hook integration issues between Claude Code and the Agent Monitor.

## Input

The user provides: **$ARGUMENTS**

This may be:
- "full" or empty (default: run all diagnostics)
- "install" to check hook installation only
- "connectivity" to check dashboard connectivity only
- "events" to check event delivery only

## Procedure

Run diagnostic checks in this order:

### 1. Hook Installation Check
Verify hooks are installed in Claude Code settings:

```bash
# Check if hooks exist in Claude Code settings
cat ~/.claude/settings.json | jq '.hooks // empty'
```

Verify:
- All 7 expected hook types are registered: `PreToolUse`, `PostToolUse`, `Stop`, `SubagentStop`, `Notification`, `SessionStart`, `SessionEnd`
- Hook commands point to the correct handler script path
- Handler script exists and is readable at the configured path

### 2. Dashboard Connectivity
Test that the dashboard API is reachable:

```bash
curl -sf http://localhost:4820/api/health
```

Verify:
- Dashboard responds with 200 OK
- Response includes expected health fields
- WebSocket endpoint is accessible

### 3. Hook Handler Validation
Check the hook handler script:

```bash
# Verify handler exists and is executable
ls -la <handler-path>
# Syntax check
node --check <handler-path>
```

### 4. Event Delivery Test
Send a test event and verify it arrives:

```bash
echo '{"hook_type":"test","session_id":"diag-test","data":{}}' | \
  curl -sf -X POST http://localhost:4820/api/hooks/event \
  -H 'Content-Type: application/json' -d @-
```

### 5. Database Check
Verify the database is writable and events are persisted:

```bash
curl -sf http://localhost:4820/api/stats
curl -sf http://localhost:4820/api/events?limit=5
```

### 6. Recent Event Flow
Check if events are flowing:
- Time since last event received
- Events received in last hour
- Any gaps in event delivery

## Output Format

The rest: https://github.com/hoangsonww/Claude-Code-Agent-Monitor/blob/HEAD/plugins/ccam-devtools/skills/hook-diagnostics/SKILL.md