Check disposable email and signup patterns before granting free trials or AI credits. Get an allow, review, or block verdict and enforce the right policy in your backend.
Hits the same endpoint as production. Powered by Gemini for the additional signup context. Known disposable domains can be checked locally.
POST the email (and optional IP, user agent) to /api/v1/verify when a user submits the signup form.
Check format, disposable domains, aliases, relay providers, and role accounts. AI-assisted checks can assess recent signup patterns.
Use our verdict, or roll your own policy with the raw signals. Review recorded checks in your dashboard and tune your rules.
Match email domains against our bundled snapshot of the open disposable-email-domains list. Combine that result with format, alias, relay, and role-account signals.
Use the free checker →AI-assisted checks can use recent registration context, including supplied usernames and IPs, to score suspicious patterns. Treat the score as a reason to investigate, not proof that accounts belong to one person.
Build your trial protection policy →Call the API from your backend, or start with our TypeScript helper. Keep secrets server-side and check eligibility before granting trial benefits.
Read the Next.js integration guide →
curl https://trueuser.dev/api/v1/verify \
-H "Authorization: Bearer tu_live_••••" \
-H "Content-Type: application/json" \
-d '{
"email": "[email protected]",
"ip": "203.0.113.42"
}'{
"verdict": "block",
"signals": {
"format_valid": true,
"disposable": true,
"public_domain": false,
"relay_domain": false,
"alias": false,
"role_account": false,
"spam": false,
"suspicious_pattern": 0.84,
"batch_cluster": 0.91
},
"reasoning": "Disposable provider with batch-shaped local part.",
"latency_ms": 68
}Paste this into Claude Code, Codex, Cursor, or your preferred coding agent in your project. It covers the API contract, server-side secrets, failure handling, and trial-credit safeguards.
Add your real API key to your server environment after reviewing the generated changes.
For prototyping and side projects.
Drag to pick the volume you need. Switch tiers anytime.
How signup checks fit into your product, what the signals mean, and how to protect your trial without turning away real customers.
Yes. Copy the integration prompt on this page into your coding agent inside your project. It asks the agent to inspect your auth and credit flows, call TrueUser from the server, handle failures, and test the eligibility policy. Review the generated changes and configure your server API key before deploying.
Yes. The free disposable email checker looks up a domain in our bundled blocklist without an account or API key. A missing entry does not prove that the address is safe or deliverable. Use the API when you need more signals and configurable verdict rules in your signup flow.
TrueUser evaluates email format, disposable domains, aliases, privacy relays, role accounts, and suspicious signup patterns. Optional AI analysis can assess patterns among recent registrations. Your configured rules turn those signals into an allow, review, or block verdict, with reasoning your application can use.
Check signup risk before granting credits, then use the verdict to offer a normal trial, a smaller allowance, or additional review. TrueUser supplies the assessment; your backend controls access and enforces usage limits. This helps you limit what suspicious accounts can consume while preserving a path for legitimate customers.
TrueUser can assess similarities among recent signups using email patterns and the usernames and IP addresses you supply. Its batch score is a risk estimate, not proof that accounts belong to the same person. Shared networks and similar names can also belong to unrelated users.
No. An email confirmation link checks whether someone can access an inbox. TrueUser assesses signup risk; it does not prove mailbox ownership, deliverability, or identity. Use both when your product needs email confirmation and a separate decision about trial eligibility.
An alias or privacy relay is a signal, not proof of abuse. You control how signals affect your verdict rules and how your application responds. For uncertain signups, consider a limited trial or review step, and give legitimate customers a way to resolve restrictions.
Call POST /api/v1/verify from your backend with an API key and an email address. You can also include a username and client IP. Store the returned verdict, apply your trial policy before granting expensive benefits, and define a timeout and fallback policy for unavailable checks. Keep the API key on your server.