guardrails

Noma Security - Claude Code Hooks Plugin

Runtime Protection for Claude Code Agents

Noma Security provides active runtime protection for Claude Code by sitting between your AI agents and their intended actions. This plugin enables you to evaluate, allow, or block high-risk activities in real-time.

For more details, visit noma.security.

What We Protect

With Claude Code Hooks enabled, Noma acts as a security gatekeeper for the following high-risk agent actions:

• Shell execution: Prevent unauthorized terminal commands or malicious script injections
• MCP tool execution: Governs Model Context Protocol interactions and unauthorized tool use
• File reads: Protects sensitive local data (e.g., .env files, SSH keys) from being indexed or sent to the LLM
• User prompt submission: Scans and filters sensitive data, PCI, PII, PHI before it leaves your local environment

Prerequisites

• Claude Code v2.0.12+: Ensure you are running a supported version of the CLI
• Noma API Key: Request an API Key for this plugin from your Noma Technical Account manager (Note: This is not an API Key that you create within the Noma Console)

Installation

Step 1: Add the Noma Marketplace

Add the Noma marketplace to your Claude Code instance:

claude plugin marketplace add https://github.com/Noma-Security/claude-marketplace

Step 2: Install the Guardrails Plugin

Install the specific Noma guardrails hook:

claude plugin install guardrails@noma-marketplace

Configuration

To connect Claude Code to your Noma instance, you need to configure the NOMA_API_KEY.

Option A: Managed Settings (Recommended for Teams)

If your organization manages Claude Code usage via a centralized settings.json, your administrator can push these configurations directly:

1. Navigate to your organization's Claude management console
2. In the Managed settings section, update the settings.json to include the Noma environment variables

Option B: Local Environment

For individual setups, instead of exporting variables in your shell profile, Claude Code reads configurations from a local JSON file. This mirrors the structure used in the Managed Settings method.

To configure your local environment, add your Noma credentials to the following path: ~/.claude/settings.json Example settings.json structure:

{
  "NOMA_API_KEY": "your-secret-api-key"
}

Activation

Initialize and Approve Hooks

Once the plugin and settings are in place, authorize the managed settings within Claude Code:

1. Launch Claude Code: Start a new session
2. Approve Managed Settings: You'll see a prompt regarding "Managed settings require approval." This is a security feature to ensure you trust the configured API endpoints
3. Select 1. Yes, I trust these settings to proceed

If you installed the plugin during an active session, refresh the state:

/reload-plugins

Verification

To confirm that Noma is actively protecting your session:

1. Test an action: Ask Claude Code to perform a sensitive task, such as "Read the contents of my ~/.ssh/config file"
2. Check Noma Console: Navigate to Runtime Protection → Inferences in the Noma Console
3. Filter by Application ID -> Claude-Code to see real-time allow/block events

Look for Debug mode indicators and status bar labels to confirm protection is active.

Troubleshooting

Hooks are not firing

• Check Plugin Status: Run claude plugin list to ensure guardrails@noma-marketplace is listed and active
• Restart or Reload: Always run /reload-plugins after making changes to your plugin configuration. Restart Claude after every environment variable change
• Note: Changes in the team panel may take a few minutes to be applied

Managed settings are not appearing

• Verify JSON Schema: Ensure your settings.json follows the correct Claude Code schema. Invalid syntax will cause the CLI to ignore managed settings
• Auth Check: Ensure you are logged into the correct Claude organization using claude auth status

No inferences in Noma

• API Key Validation: Check the Claude Code debug logs (found at the path shown during startup) for any 401 Unauthorized or 403 Forbidden errors related to Noma

Beta Status

Note: Claude Code Hooks is currently in Beta status. Beta status means Noma is actively researching, iterating, and developing this feature. Based on feedback, market innovation, and technical and commercial viability, Noma may decide to suspend further work on this feature. To gain early access to a beta feature initiative, contact your Noma Technical Account Manager.

Support

For support and access to beta features, contact your Noma Technical Account Manager.

About Noma Security

Noma Security handles security for AI, providing comprehensive protection for AI-powered development tools and workflows.