Building an AI agent with OpenClaw (formerly Moltbot or Clawdbot)? Your users will send all kinds of messages—and some will contain profanity. You need to handle it before it reaches your AI and before it costs you money.
In this OpenClaw profanity filter tutorial, I'll show you how to integrate openclaw-profanity—a free, open-source content moderation plugin built specifically for OpenClaw, Moltbot, and Clawdbot agents. Works with WhatsApp bots, Telegram bots, Discord bots, and Slack bots.
TL;DR: Install with
npm install openclaw-profanity, add one hook, and every message is filtered. No API costs. No latency. Skip to Quick Start
Table of Contents
- The Problem: AI-Based Profanity Checking Is Expensive
- Why openclaw-profanity?
Integration Guide for OpenClaw
- Option 1: Profanity Guard Hook
- Option 2: Custom Skill
- Option 3: Direct Integration
- Platform-Specific Examples
- Advanced: Hybrid AI + Local Filtering
- Configuration Options
- Quick Start
- FAQ
The Problem: AI-Based Profanity Checking Is Expensive
Your agent already uses GPT, Claude, or Gemini. Why not ask the AI to check for profanity?
Here's what that costs:
| Messages/Day | Monthly Cost (AI-only) | With openclaw-profanity |
|---|---|---|
| 500 | $5-15 | $0 |
| 1,000 | $10-30 | $0 |
| 5,000 | $50-150 | $0 |
| 10,000 | $100-300 | $0 |
That's just for profanity checking. Before your agent does anything useful.
The other problems with AI-only moderation:
| Issue | AI-Only | openclaw-profanity |
|---|---|---|
| Latency | 200-500ms per check | < 1ms |
| Rate limits | Traffic spikes fail | No limits |
| Downtime | API outage = bot down | Always available |
| Consistency | Results vary | Deterministic |
| Cost scaling | Linear increase | Zero cost |
Why openclaw-profanity?
We built openclaw-profanity because every other solution either:
- Fails basic evasion tactics (leetspeak, Unicode tricks)
- Requires expensive API calls
- Lacks proper OpenClaw integration
- Only supports English
What makes openclaw-profanity different:
1. Catches What Others Miss
Most profanity filters fail against basic evasion tactics. Users type f*ck or sh1t and walk right through.
| Evasion Method | Example | Other Filters | openclaw-profanity |
|---|---|---|---|
| Leetspeak | f4ck, sh1t, @ss | ❌ | ✅ |
| Unicode substitution | fսck (Cyrillic у) | ❌ | ✅ |
| Character spacing | f u c k | ❌ | ✅ |
| Symbols | f*ck, f@ck, $hit | ❌ | ✅ |
| Mixed case | FuCk, sHiT | ❌ | ✅ |
| Repeated chars | fuuuuck, shiiit | ❌ | ✅ |
2. True Multilingual Support
24 languages built-in: English, Spanish, French, German, Portuguese, Italian, Dutch, Russian, Chinese, Japanese, Korean, Arabic, Hindi, Turkish, Polish, Vietnamese, Thai, Swedish, Norwegian, Danish, Finnish, Czech, Hungarian, Greek
Not just word lists—actual linguistic patterns for each language.
3. Native OpenClaw Integration
Built FOR OpenClaw, not adapted to it. First-class support for:
Hooks - Automatic message filtering
Skills - Callable actions for your agent
Direct API - Full control when you need it
4. Zero Dependencies (Almost)
One dependency: glin-profanity (our core library). No network calls. No external services. Everything runs locally on your server.
Integration Guide for OpenClaw
Option 1: Profanity Guard Hook (Recommended)
The simplest integration. Add one hook and every message is automatically filtered.
import { OpenClawAgent } from "openclaw";
import { profanityGuardHook } from "openclaw-profanity/hooks";
const agent = new OpenClawAgent({
// your config
});
// Add the profanity guard - that's it!
agent.useHook(profanityGuardHook({
action: "censor", // "censor" or "block"
languages: ["en", "es"], // languages to check
replacement: "***", // censorship character
onViolation: (msg, result) => {
console.log(`Filtered: ${result.profaneWords.join(", ")}`);
}
}));
agent.start();
Actions:
action: "censor"- Replaces profanity with***and continues processing
action: "block"- Stops the message entirely, sends warning to user
That's 3 lines of code for complete profanity protection.
Option 2: Custom Skill
Create a reusable skill your agent can call programmatically.
import { defineSkill } from "openclaw";
import { checkProfanity, censorText } from "openclaw-profanity/skills";
export const moderationSkill = defineSkill({
name: "content-moderation",
description: "Check and filter profanity from user messages",
actions: {
check: {
description: "Check text for profanity",
parameters: {
text: { type: "string", required: true }
},
handler: async ({ text }) => {
const result = checkProfanity(text);
return {
containsProfanity: result.containsProfanity,
profaneWords: result.profaneWords,
confidence: result.confidence
};
}
},
censor: {
description: "Censor profanity in text",
parameters: {
text: { type: "string", required: true }
},
handler: async ({ text }) => {
const result = censorText(text);
return {
original: result.originalText,
censored: result.processedText,
wordsCensored: result.censoredWords
};
}
}
}
});
Register it:
import { moderationSkill } from "./skills/moderation";
agent.useSkill(moderationSkill);
Option 3: Direct Integration
For full control, use the library directly in your message handler.
import { checkProfanity, censorText } from "openclaw-profanity";
async function handleIncomingMessage(message, context) {
// Step 1: Check for profanity (< 1ms)
const check = checkProfanity(message.text, {
languages: ["en", "es", "fr"],
detectLeetspeak: true,
detectUnicode: true
});
// Step 2: Handle based on result
if (check.containsProfanity) {
if (check.confidence > 0.9) {
// High confidence - block immediately
return context.reply(
"Please keep the conversation respectful."
);
}
// Medium confidence - censor and continue
const censored = censorText(message.text);
message.text = censored.processedText;
}
// Step 3: Continue to AI processing
return context.next(message);
}
Platform-Specific Examples
WhatsApp Bot (with OpenClaw)
import { WhatsAppAdapter } from "openclaw/adapters/whatsapp";
import { profanityGuardHook } from "openclaw-profanity/hooks";
const agent = new OpenClawAgent({
adapter: new WhatsAppAdapter({
// WhatsApp config
})
});
agent.useHook(profanityGuardHook({
action: "censor",
languages: ["en", "es", "pt"], // English, Spanish, Portuguese
onViolation: (msg, result) => {
// Log for moderation dashboard
logViolation(msg.from, result);
}
}));
Telegram Bot
import { TelegramAdapter } from "openclaw/adapters/telegram";
import { profanityGuardHook } from "openclaw-profanity/hooks";
const agent = new OpenClawAgent({
adapter: new TelegramAdapter({
token: process.env.TELEGRAM_BOT_TOKEN
})
});
agent.useHook(profanityGuardHook({
action: "block",
warningMessage: "Please keep the chat friendly!"
}));
Discord Bot
import { DiscordAdapter } from "openclaw/adapters/discord";
import { profanityGuardHook } from "openclaw-profanity/hooks";
const agent = new OpenClawAgent({
adapter: new DiscordAdapter({
token: process.env.DISCORD_BOT_TOKEN
})
});
agent.useHook(profanityGuardHook({
action: "censor",
// Discord-specific: delete original and repost censored
onViolation: async (msg, result, context) => {
await msg.delete();
await context.reply(`${msg.author}: ${result.censoredText}`);
}
}));
Slack Bot
import { SlackAdapter } from "openclaw/adapters/slack";
import { profanityGuardHook } from "openclaw-profanity/hooks";
const agent = new OpenClawAgent({
adapter: new SlackAdapter({
token: process.env.SLACK_BOT_TOKEN
})
});
agent.useHook(profanityGuardHook({
action: "censor",
onViolation: async (msg, result) => {
// Notify workspace admins
await notifyAdmins(msg.channel, result);
}
}));
Advanced: Hybrid AI + Local Filtering
The smart approach: Use local filtering for speed, escalate edge cases to AI.
import { checkProfanity } from "openclaw-profanity";
async function smartModeration(message, agent) {
// Fast local check (< 1ms)
const localCheck = checkProfanity(message.text);
if (!localCheck.containsProfanity) {
// Clean - proceed immediately
return { action: "allow" };
}
if (localCheck.confidence > 0.95) {
// Definitely profane - block without AI call
return { action: "block" };
}
// Uncertain - ask AI for context analysis (rare)
const aiAnalysis = await agent.analyze({
prompt: `Is this message inappropriate? Consider context and intent: "${message.text}"`,
format: "json"
});
return aiAnalysis.inappropriate
? { action: "block" }
: { action: "allow" };
}
Result:
95% of messages handled instantly (free, <1ms)
5% escalated to AI (only when genuinely ambiguous)
90%+ cost reduction vs AI-only approach
This is how production systems should work—fast local decisions, AI only when necessary.
Configuration Options
import { Filter } from "openclaw-profanity";
const filter = new Filter({
// Languages to check (default: all 24)
languages: ["en", "es", "fr"],
// Detection options
detectLeetspeak: true, // f4ck, sh1t
detectUnicode: true, // Cyrillic/Greek substitutions
detectSpacing: true, // f u c k
// Censorship options
replaceWith: "*", // Replacement character
preserveLength: true, // **** vs ***
// Whitelist (words to ignore)
whitelist: ["assistant", "class"],
// Custom words to add
customWords: ["badword1", "badword2"]
});
Quick Start
1. Install:
npm install openclaw-profanity
2. Add hook to your agent:
import { profanityGuardHook } from "openclaw-profanity/hooks";
agent.useHook(profanityGuardHook({
action: "censor"
}));
3. Done. Every message is now filtered.
Total setup time: Under 2 minutes.
FAQ
Does this replace my AI moderation completely?
It can, but we recommend the hybrid approach. Use openclaw-profanity for the 95% of cases that are clear-cut, and let your AI handle the ambiguous 5% that need context understanding.
Will it slow down my bot?
No. Response time is under 1 millisecond. That's 200-500x faster than an API call.
What about false positives?
The library includes smart word boundaries and context detection. "Scunthorpe" won't be flagged. You can also add whitelists for domain-specific terms.
Can I add custom words?
Yes. Add any custom words to your filter configuration. They'll inherit all the evasion detection (leetspeak, Unicode, etc.) automatically.
Does it work with Moltbot/Clawdbot?
Yes! OpenClaw is the current name for the framework formerly known as Moltbot and Clawdbot. The integration works the same way.
Is it production-ready?
Yes. The core library (glin-profanity) is battle-tested and handles edge cases like Unicode normalization, boundary detection, and performance optimization.
Why Developers Choose openclaw-profanity
Zero cost - No API fees, runs entirely local
Sub-millisecond - Faster than any cloud solution
24 languages - True multilingual support
Evasion-proof - Catches leetspeak, Unicode tricks, and more
Native OpenClaw - Built for your stack
MIT licensed - Use it anywhere, modify as needed
Links & Resources
npm: openclaw-profanity
GitHub: GLINCKER/glin-profanity
Documentation: Integration Guide
Live Demo: glincker.com/tools/glin-profanity
Part of the glin-profanity Ecosystem
openclaw-profanity is built on glin-profanity, which also powers:
glin-profanity-mcp - MCP server for Claude Desktop, Cursor, Windsurf
glin-profanity (Python) - Python version for Flask/Django
Same core engine. Same detection quality. Different integrations for different needs.
Get Started Now
npm install openclaw-profanity
Your bot deserves better than paying $100+/month for profanity checking. Add one line of code and solve it forever.
Questions? Drop a comment below or open an issue on GitHub.
What messaging platform are you building for? I'd love to hear about your use case!
Summary
openclaw-profanity is a free, open-source profanity filter plugin for OpenClaw, Moltbot, and Clawdbot AI agents. Key features:
Zero cost - No API calls, runs locally
Sub-millisecond performance - 200-500x faster than AI moderation
24 languages - Full multilingual support
Evasion detection - Catches leetspeak, Unicode tricks, character spacing
Easy integration - Hooks, Skills, or Direct API
Platform support - WhatsApp, Telegram, Discord, Slack
Install now: npm install openclaw-profanity
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