Eliminate Fake Signups
with AI Precision
Merlin is a lightning-fast, AI-powered disposable email detector. Protect your deliverability and keep your user base clean with our simple API.
No credit card or phone number required to get started
Try Merlin Now
Enter a domain or a full email address to see Merlin in action.
No credit card or phone number required.
Why Merlin?
Standard blocklists aren't enough. Merlin combines traditional data with AI logic to stay ahead of disposable email providers.
Global Blocklist
AI Forensic Analysis
Infrastructure Validation
Ultra-Low Latency
Smart Allowlist
High Deliverability
How to Get Started
Follow these simple steps to start using Merlin AI in your production environment.
Create an Account
Sign up for SpendInBox to get your own expense inbox and a free Merlin API key.
Sign up now →Get Your API Key
Once logged in, your API key will automatically appear below.
••••••••••••••••Start Validating
Integrate our endpoint into your signup flow. Flexible free tier available for developers.
curl -H "X-API-Key: YOUR_API_KEY" \
"https://merlin.spendinbox.com/api/check/tempmail.com"{
"is_disposable": true,
"domain": "tempmail.com",
"is_valid_domain": true
}Ready to Take Control of Your Expenses?
Create your free account now and start tracking your expenses automatically.