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security-sandbox

Secure command execution with allowlists and validation hooks. Use when validating bash commands, configuring security policies, implementing pre-tool-use hooks, or sandboxing autonomous agent operations.

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The canonical home for this skill is security-sandbox in fernandezbaptiste/Skrillz

SKILL.md
Quality
Evals
Security

Security Sandbox

Provides defense-in-depth security for autonomous coding operations through command validation, allowlists, and execution hooks.

Quick Start

Validate a Command

from scripts.command_validator import validate_command

result = validate_command("npm install express")
if result.allowed:
    # Safe to execute
    pass
else:
    print(f"Blocked: {result.reason}")

Use Security Hook

from scripts.security_manager import create_bash_security_hook

hook = create_bash_security_hook()

# Hook returns decision for Claude SDK
decision = await hook({
    "tool_input": {"command": "rm -rf /"}
})
# decision = {"decision": "block", "reason": "Command 'rm' requires approval"}

Configure Allowlist

from scripts.allowlist import Allowlist

allowlist = Allowlist()
allowlist.add("docker")
allowlist.add("kubectl")
allowlist.remove("rm")  # Disallow rm

Security Model

┌─────────────────────────────────────────────────────────────┐
│                   DEFENSE IN DEPTH                           │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  LAYER 1: SANDBOX                                           │
│  ├─ OS-level isolation                                      │
│  ├─ Filesystem restrictions                                 │
│  └─ Network limitations                                     │
│                                                              │
│  LAYER 2: PERMISSIONS                                       │
│  ├─ Tool allowlist (Read, Write, Bash...)                  │
│  ├─ Path restrictions (./**)                               │
│  └─ Operation limits                                        │
│                                                              │
│  LAYER 3: COMMAND VALIDATION                                │
│  ├─ Command extraction & parsing                            │
│  ├─ Allowlist checking                                      │
│  └─ Dangerous pattern detection                             │
│                                                              │
│  LAYER 4: HOOKS                                             │
│  ├─ PreToolUse validation                                   │
│  ├─ Real-time blocking                                      │
│  └─ Audit logging                                           │
│                                                              │
└─────────────────────────────────────────────────────────────┘

Default Allowlist

ALLOWED_COMMANDS = {
    # File inspection
    "ls", "cat", "head", "tail", "wc", "grep", "find",
    # File operations
    "cp", "mkdir", "chmod", "touch",
    # Node.js
    "npm", "node", "npx", "yarn", "pnpm",
    # Python
    "python", "python3", "pip", "pip3", "poetry",
    # Version control
    "git",
    # Process management
    "ps", "lsof", "sleep", "pkill", "kill",
    # System info
    "pwd", "whoami", "uname", "which", "env",
    # Network (limited)
    "curl", "wget",
}

Dangerous Patterns

These patterns are always blocked:

PatternRiskExample
rm -rf /System destructionWipes filesystem
> /dev/sdaDisk corruptionOverwrites disk
chmod 777Security holeWorld-writable
curl | bashCode injectionRemote execution
:(){ :|:& };:Fork bombDoS attack
dd if=/dev/zeroDisk fillResource exhaustion

Hook Integration

# For Claude SDK integration
from scripts.security_manager import SecurityManager

manager = SecurityManager()

# Configure SDK with hooks
sdk_options = {
    "hooks": {
        "PreToolUse": [manager.pre_tool_hook]
    }
}

Integration Points

  • autonomous-session-manager: Provides security during sessions
  • coding-agent: Uses hooks for safe command execution
  • autonomous-loop: Ensures safety in continuous operation

References

  • references/ALLOWED-COMMANDS.md - Full allowlist documentation
  • references/SECURITY-MODEL.md - Security architecture
  • references/CUSTOM-RULES.md - Custom rule configuration

Scripts

  • scripts/security_manager.py - Core security manager
  • scripts/command_validator.py - Command validation
  • scripts/allowlist.py - Allowlist management
  • scripts/sandbox_config.py - Sandbox configuration
Repository
fernandezbaptiste/Skrillz
Path

.claude/skills/security-sandbox/SKILL.md

Commit

93ed392

Last updated
First committed

Canonical home

fernandezbaptiste/Skrillz
In sync

since Sep 12, 2026

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