Hooks Examples

Block Dangerous Commands

Block shell commands that could be destructive:Hook Script (/etc/augment/hooks/security-block-dangerous.sh):

#!/usr/bin/env bash

EVENT_DATA=$(cat)
COMMAND=$(echo "$EVENT_DATA" | jq -r '.tool_input.command // ""')

# Check for dangerous patterns
if echo "$COMMAND" | grep -qE "rm -rf|sudo|chmod 777"; then
  echo "Blocked dangerous command: $COMMAND" >&2
  exit 2
fi

exit 0

#!/usr/bin/env python3
import sys
import json
import re

event_data = json.load(sys.stdin)
command = event_data.get('tool_input', {}).get('command', '')

# Check for dangerous patterns
if re.search(r'rm -rf|sudo|chmod 777', command):
    print(f"Blocked dangerous command: {command}", file=sys.stderr)
    sys.exit(2)

sys.exit(0)

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "launch-process",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/security-block-dangerous.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

Auto-Format Code Before Editing

Automatically format code files using language-specific formatters (Biome, Ruff, gofmt, rustfmt) before the agent edits them.Hook Script (/etc/augment/hooks/auto-format.sh):

#!/usr/bin/env bash

EVENT_DATA=$(cat)
TOOL_NAME=$(echo "$EVENT_DATA" | jq -r '.tool_name')

# Only run for file editing tools
[[ "$TOOL_NAME" != "str-replace-editor" ]] && exit 0

FILE_PATH=$(echo "$EVENT_DATA" | jq -r '.tool_input.path // ""')
[[ -z "$FILE_PATH" || ! -f "$FILE_PATH" ]] && exit 0

EXT="${FILE_PATH##*.}"

case "$EXT" in
  ts|tsx|js|jsx) command -v biome &>/dev/null && biome format --write "$FILE_PATH" ;;
  py) command -v ruff &>/dev/null && ruff format "$FILE_PATH" ;;
  go) command -v gofmt &>/dev/null && gofmt -w "$FILE_PATH" ;;
  rs) command -v rustfmt &>/dev/null && rustfmt "$FILE_PATH" ;;
esac

exit 0

#!/usr/bin/env python3
import sys, json, subprocess, shutil
from pathlib import Path

event_data = json.load(sys.stdin)
if event_data.get('tool_name') != 'str-replace-editor':
    sys.exit(0)

file_path = event_data.get('tool_input', {}).get('path', '')
if not file_path or not Path(file_path).exists():
    sys.exit(0)

ext = Path(file_path).suffix.lstrip('.')
formatters = {
    'ts': ['biome', 'format', '--write'],
    'tsx': ['biome', 'format', '--write'],
    'js': ['biome', 'format', '--write'],
    'py': ['ruff', 'format'],
    'go': ['gofmt', '-w'],
    'rs': ['rustfmt'],
}

if ext in formatters and shutil.which(formatters[ext][0]):
    subprocess.run(formatters[ext] + [file_path], timeout=30)

sys.exit(0)

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "str-replace-editor",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/auto-format.sh",
            "timeout": 30000
          }
        ]
      }
    ]
  }
}

Supported Formatters:

Language	Formatter	Command
TypeScript/JavaScript	Biome	`biome format --write`
Python	Ruff	`ruff format`
Go	gofmt	`gofmt -w`
Rust	rustfmt	`rustfmt`

Audit Sensitive File Access

Monitor when the agent accesses sensitive files:Hook Script (/etc/augment/hooks/audit.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)
FILE_PATH=$(echo "$EVENT_DATA" | jq -r '.tool_input.path // ""')

if echo "$FILE_PATH" | grep -qE "\.env|secrets|credentials"; then
  echo "[AUDIT] Sensitive file access: $FILE_PATH" >&2
fi

exit 0  # Audit only, don't block

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "view|str-replace-editor",
        "hooks": [
          { "type": "command", "command": "/etc/augment/hooks/audit.sh" }
        ]
      }
    ]
  }
}

Block Sudo Commands

A simple hook to block sudo commands:Hook Script (/etc/augment/hooks/validate-tool.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)
COMMAND=$(echo "$EVENT_DATA" | jq -r '.tool_input.command // ""')

if echo "$COMMAND" | grep -q "sudo"; then
  echo "Blocked: sudo not allowed" >&2
  exit 2  # Block execution
fi

exit 0

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "launch-process",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/validate-tool.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

Load Context at Session Start

Inject development context when a session starts:Hook Script (/etc/augment/hooks/load-context.sh):

#!/usr/bin/env bash

# Load recent git commits
echo "Recent commits:"
git log --oneline -5

# Load current branch info
echo ""
echo "Current branch: $(git branch --show-current)"

# Load open issues (example)
echo ""
echo "Open issues:"
# curl -s https://api.example.com/issues | jq -r '.[] | "- \(.title)"'

exit 0

#!/usr/bin/env python3
import sys
import subprocess

# Load recent git commits
print("Recent commits:")
result = subprocess.run(['git', 'log', '--oneline', '-5'],
                       capture_output=True, text=True)
print(result.stdout)

# Load current branch info
print("")
print("Current branch:", end=" ")
result = subprocess.run(['git', 'branch', '--show-current'],
                       capture_output=True, text=True)
print(result.stdout.strip())

sys.exit(0)

Configuration:

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/load-context.sh",
            "timeout": 10000
          }
        ]
      }
    ]
  }
}

Session Cleanup

Run cleanup when a session ends:Hook Script (/etc/augment/hooks/cleanup.sh):

#!/usr/bin/env bash
echo "[$(date)] Session ended" >&2
exit 0

Configuration:

{
  "hooks": {
    "SessionEnd": [
      {
        "hooks": [
          { "type": "command", "command": "/etc/augment/hooks/cleanup.sh" }
        ]
      }
    ]
  }
}

Block Production Database Access

Prevent agents from accessing production systems or sensitive data:Hook Script (/etc/augment/hooks/block-prod.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)
TOOL_INPUT=$(echo "$EVENT_DATA" | jq -r '.tool_input | tostring')

if echo "$TOOL_INPUT" | grep -qE "prod-db|production\.database"; then
  echo "Access to production databases is not allowed" >&2
  exit 2
fi

exit 0

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/block-prod.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

Compliance Auditing

Log all tool executions for compliance:Hook Script (/etc/augment/hooks/audit-log.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)
TOOL=$(echo "$EVENT_DATA" | jq -r '.tool_name')
echo "[$(date -u +%FT%TZ)] Tool: $TOOL" >&2
exit 0

Configuration:

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/audit-log.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

Rate Limiting MCP Tools

Block excessive API calls to MCP servers:Hook Script (/etc/augment/hooks/rate-limit.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)
SERVER=$(echo "$EVENT_DATA" | jq -r '.mcp_metadata.mcpExecutedToolServerName // ""')
RATE_FILE="/tmp/rate-$SERVER"
COUNT=$(cat "$RATE_FILE" 2>/dev/null || echo "0")

if [ "$COUNT" -gt 10 ]; then
  echo "Rate limit exceeded" >&2
  exit 2
fi

echo $((COUNT + 1)) > "$RATE_FILE"
exit 0

Configuration:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "mcp:*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/rate-limit.sh",
            "timeout": 5000
          }
        ],
        "metadata": {
          "includeMCPMetadata": true
        }
      }
    ]
  }
}

Require Tests Before Finishing

Block the agent from stopping until tests are modified:Hook Script (/etc/augment/hooks/require-tests.sh):

#!/usr/bin/env bash
EVENT_DATA=$(cat)

# Extract code changes
CODE_RESPONSE=$(echo "$EVENT_DATA" | jq -r '.conversation.agentCodeResponse // []')

# Check if any test files were modified
TEST_FILES=$(echo "$CODE_RESPONSE" | jq -r '.[] | select(.path | test("test|spec")) | .path')

if [[ -z "$TEST_FILES" ]]; then
  # No test files modified - block stop
  cat << EOF
{
  "hookSpecificOutput": {
    "hookEventName": "Stop",
    "decision": "block",
    "reason": "Please add or update tests before finishing"
  }
}
EOF
  exit 0
fi

exit 0

#!/usr/bin/env python3
import sys
import json
import re

event_data = json.load(sys.stdin)
conversation = event_data.get('conversation', {})
code_response = conversation.get('agentCodeResponse', [])

# Check if any test files were modified
test_files = [
    change['path'] for change in code_response
    if re.search(r'test|spec', change.get('path', ''))
]

if not test_files:
    output = {
        "hookSpecificOutput": {
            "hookEventName": "Stop",
            "decision": "block",
            "reason": "Please add or update tests before finishing"
        }
    }
    print(json.dumps(output))
    sys.exit(0)

sys.exit(0)

Configuration:

{
  "hooks": {
    "Stop": [
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/require-tests.sh",
            "timeout": 5000
          }
        ],
        "metadata": {
          "includeConversationData": true
        }
      }
    ]
  }
}

Multiple Hooks on Same Event

Execute multiple hooks in order for the same event:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "launch-process",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/log-command.sh",
            "timeout": 5000
          },
          {
            "type": "command",
            "command": "/etc/augment/hooks/security-check.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

If any hook returns exit code 2, execution is blocked and subsequent hooks are not run.

Combining Matchers

Use multiple matcher configurations for different tools:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "mcp:*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/log-mcp.sh",
            "timeout": 5000
          }
        ]
      },
      {
        "matcher": "launch-process",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/security-bash.sh",
            "timeout": 5000
          }
        ]
      },
      {
        "matcher": ".*",
        "hooks": [
          {
            "type": "command",
            "command": "/etc/augment/hooks/audit-all.sh",
            "timeout": 5000
          }
        ]
      }
    ]
  }
}

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See Also

​Example Hooks

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Example Hooks

Advanced Configuration Patterns

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