# Messageguard

> MessageGuard: Outgoing Message Filter Skill

- Skill: `javimosch/messageguard` (Agent Skill)
- Install (CLI): `npx skillmds@latest add javimosch/messageguard`
- Raw SKILL.md: https://api.skillmd.com/api/skills/javimosch/messageguard/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: javimosch (https://skillmd.com/u/javimosch)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/javimosch/messageguard

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### MessageGuard: Outgoing Message Filter Skill

**Purpose**: MessageGuard filters outgoing text to prevent secret leaks and sensitive data exposure by using pattern-based detection and configurable actions (mask, block, or warn).

### Advanced Configuration Options:

- **`mode`**: Determines the global action for matched patterns. Options are:
  - `mask`: Replace sensitive data with the `mask_char`.
  - `block`: Prevent the message from being sent entirely.
  - `warn`: Allow the message but generate warnings.
- **`mask_char`**: The character(s) used to replace sensitive content when `mode` is set to `mask`.
- **`patterns`**: Define or customize regex-based detections. Built-ins exist for API keys, credentials, and more (e.g., AWS keys, JWTs). Add new patterns based on your requirements.
- **`logging`**: Enable detections to be logged as structured JSON for monitoring, debugging, or compliance needs. Configure the `log_path` for the output location.
- **Custom Patterns**: Users can define their custom patterns to override built-ins or extend functionalities. This supports regex and granular action control (mask, block, warn).

**Installation**
1. Clone the repository: `git clone git@github.com:AndrewAndrewsen/MessageGuard.git`.
2. Navigate to the directory. The skill is dependency-free, relying only on the Python standard library.