How I Protected My Telegram Bot's AI Quota From Spam Users

Rooter — Sun, 20 Sep 2026 16:52:48 +0000

I run a Telegram bot that uses Google's Gemini API for free-tier AI features. The free tier gives 1,500 requests per day.

Last week, one user sent 1,400 messages in 3 hours.

The result? 999+ users got "quota exceeded" errors. My entire AI feature was dead for the day.

Here's how I fixed it.

The Problem

Free AI APIs have hard daily limits. One aggressive user can consume the entire quota. There's no native protection unless you build it.

I needed:

Per-user rate limiting
Global daily cap
Response caching for common questions

The Fix — 3 Layers

Layer 1: Per-User Rate Limit

def check_rate_limit(user_id):
now = time.time()
hour_ago = now - 3600
uid = str(user_id)
user_requests.setdefault(uid, [])
user_requests[uid] = [t for t in user_requests[uid] if t > hour_ago]
if len(user_requests[uid]) >= 20:
return False
user_requests[uid].append(now)
return True
20 messages per hour per user. 99% users never hit this.

Layer 2: Global Daily Cap

global_counter = {"date": "...", "count": 0}

def check_global_limit():
today = datetime.utcnow().strftime("%Y-%m-%d")
if global_counter["date"] != today:
global_counter["date"] = today
global_counter["count"] = 0
if global_counter["count"] >= 1400:
return False
global_counter["count"] += 1
return True
Cap at 1,400 — 100 buffer below the 1,500 limit.

Layer 3: Response Cache

answer_cache = {}

cached = answer_cache.get(question.lower().strip())
if cached:
return cached

answer_cache[question.lower().strip()] = answer
Common questions like "What is Bitcoin?" get cached. Repeat users hit cache, not API.

The Results
Spam blocked: 20 msg/hour limit

99% users unaffected

Quota saved: 50-70% via caching

Zero extra cost: All in-memory, no database

What I Learned
Free tiers are fragile. Build protection before you scale. Rate limiting + caching is the cheapest fix — no infrastructure needed.

Want the full script?
I packaged this as a production-tested template. Includes:

Complete quota_protection.py

Bot integration example

Setup guide

Multi-provider fallback ready

I'm building an automated Telegram empire in public. Follow along for real code, real numbers, no hype.

DEV Community: Rooter

How I Protected My Telegram Bot's AI Quota From Spam Users

The Problem

The Fix — 3 Layers

Layer 1: Per-User Rate Limit