Integration · Developer tools

Connect Claude & ChatGPT to UserCheck

Ask your AI whether an email address or domain looks disposable, is a relay or shows spam signals. It checks addresses and domains with UserCheck, including MX records and domain age, keeps your custom blocklist up to date, and reads the gates, rules and allow or block decisions behind your sign-up checks.

Connect UserCheck free

Free plan, no credit card. Takes about a minute.

Try asking

“Is [email protected] a real address or a throwaway?”
The AI checks the email in UserCheck and reports the disposable, relay and spam signals, MX records and domain age.
“Check these five sign-up domains and tell me which look suspicious.”
It checks each domain for disposable, relay and spam signals and MX records, and sums up which ones stand out.
“Block the domain fastmail-drop.net for future sign-ups.”
It adds the domain to your custom blocklist, so later checks flag it as blocked.

What your AI can do

Email and domain checks

Check an email address or domain for disposable, relay, spam and deliverability signals, with MX records and domain age.

Custom blocklist

List the domains on your blocklist, check a single domain, add new ones and remove ones you no longer want blocked.

Gates and decisions

Read your gates, the rules on each gate and the allow or block decisions they have made.

“Is acme-test.com on our blocklist?”
It looks the domain up on your custom blocklist and tells you whether it is there.
“Why was a sign-up blocked by our main gate yesterday?”
It lists the gate's recent allow and block decisions and opens the one you ask about.
“Which rules are set on our sign-up gate?”
It lists your gates, then reads the rules configured on the one you pick.

11 tools for UserCheck

These tools are switched on when you connect. You can switch any of them off, or require your approval before it runs.

add_blocklist_domainChanges dataAdd a domain to your custom blocklist so it is flagged as blocked in future checks. Required: domain.
check_domainCheck one domain (e.g. acme.com) for disposable, relay and spam signals and MX records. Pass the same domain in both `domain` and `domain_2`.
check_emailCheck one email address for disposable, relay, spam and deliverability signals (MX records, domain age and more). Pass the same address in both `email` and `email_2`; set include_mx=false to skip the MX lookup.
get_blocklist_domainCheck whether one domain is on your custom blocklist, by `domain`.
get_gateGet one gate and its settings by `gate_id`.
get_gate_decisionGet one decision a gate made, by `gate_id` and `decision_id`.
list_blocklistList the domains on your custom blocklist, with page and limit for paging.
list_gate_decisionsList the recent allow/block decisions a gate has made, by `gate_id`.
list_gate_rulesList the rules configured on a gate, by `gate_id`.
list_gatesList your gates (the sign-up rule sets that decide whether an email is allowed).
remove_blocklist_domainDeletesRemove a domain from your custom blocklist, by `domain`.

Set up in three steps

1
Pick the app
Create a free PipMCP account and choose UserCheck from the app list.
2
Paste your key
Paste your UserCheck API key. Log in to app.usercheck.com and open API Keys, then generate a new key or copy an existing one. Each key belongs to one environment (production, staging or development), so pick the key for the environment you want the AI to use.
3
Add the link to your AI
You get a personal MCP link. Add it to Claude, ChatGPT or Cursor:
1. Click your name, then Settings › Connectors › Add custom connector.
2. Paste your link as the Remote MCP server URL.
3. Switch it on from the + menu in a chat.

Questions

What can the AI do in UserCheck?

The AI can check email addresses and domains for disposable, relay, spam and deliverability signals. It can list, check, add and remove domains on your custom blocklist, and read your gates, their rules and the decisions they have made.

Does the AI see my UserCheck API key?

No. Your UserCheck credentials are encrypted at rest and never shown to the AI. After you save them, they are not shown again, not even to you. The AI only sees the results of the tools it calls.

Can I control what the AI is allowed to do?

Yes. You choose which tools are switched on, so you can start with checks only. Removing a domain from the blocklist can require your approval before it runs. Every tool call is logged.

Does it work with ChatGPT?

Yes. In ChatGPT go to Settings › Apps & Connectors › Advanced and turn on Developer mode, then add your PipMCP link. Developer mode needs a paid ChatGPT plan: Plus, Pro, Business or Enterprise. The same link also works in Claude (Settings › Connectors › Add custom connector), Cursor and other MCP clients.

What does it cost?

PipMCP has a free plan with no credit card required. Paid plans bill per completed task. You also need your own UserCheck account.

What is a gate in UserCheck?

A gate is a set of sign-up rules that decides whether an email is allowed. Through PipMCP the AI can read your gates, the rules on each gate and the allow or block decisions it has made. It cannot change gates or rules.