# Handling Commands

> Patterns for handling commands, validating input, and filtering messages in XMTP agents. Use when implementing slash commands, validators, or message filters. Triggers on command handling, input validation, or type guards.

- Skill: `kbarbel640-del/handling-commands` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add kbarbel640-del/handling-commands`
- Raw SKILL.md: https://api.skillmd.com/api/skills/kbarbel640-del/handling-commands/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- License: MIT
- Author: kbarbel640-del (https://skillmd.com/u/kbarbel640-del)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/kbarbel640-del/handling-commands

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# XMTP commands and validation

Best practices for handling commands, validating input, and filtering messages.

## When to apply

Reference these guidelines when:
- Implementing slash commands
- Validating hex strings and addresses
- Filtering message types
- Using type guards instead of type assertions

## Rule categories by priority

| Priority | Category | Impact | Prefix |
|----------|----------|--------|--------|
| 1 | Validators | CRITICAL | `validators-` |
| 2 | Filters | HIGH | `filters-` |
| 3 | Type Guards | HIGH | `guards-` |

## Quick reference

### Validators (CRITICAL)
- `validators-hex` - Use validHex() for hex string validation
- `validators-address` - Validate Ethereum addresses

### Filters (HIGH)
- `filters-message-types` - Filter by message type
- `filters-sender` - Filter out self-messages
- `filters-content` - Check for defined content

### Type Guards (HIGH)
- `guards-codec` - Use usesCodec() instead of type assertions
- `guards-content-type` - Use filter helpers for type safety

## How to use

Read individual rule files for detailed explanations:

```
rules/validators-hex.md
rules/filters-message-types.md
rules/guards-codec.md
```