UserCheck (BYOK)

UserCheck (BYOK) — connector documentation

• MCP endpoint: https://byok-usercheck.connectorbay.com/mcp
• REST API: POST https://byok-usercheck.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-usercheck.connectorbay.com/openapi.json
• Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
• Authentication: your own UserCheck UserCheck API key, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
• Health: https://byok-usercheck.connectorbay.com/health · Tool schemas: https://byok-usercheck.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/byok-usercheck · agent@connectorbay.com

What UserCheck (BYOK) is for

UserCheck (BYOK) lets an AI assistant read your own UserCheck data through the UserCheck API with a key you supply (UserCheck API key). Read-only: 9 tools (check_email, check_domain, get_account_usage, list_blocklist, list_gates, get_gate, list_gate_rules, get_gate_rule, list_gate_decisions). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to api.usercheck.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by UserCheck. UserCheck and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

• "Is octocat@github.com a disposable or role-account email address?"
• "Is mailinator.com a disposable email domain?"
• "How many UserCheck credits do I have left this month?"
• "Which domains are on our UserCheck blocklist?"
• "Which UserCheck gates do we have and what is their default action?"
• "What is the default action of a given UserCheck gate?"

What it does

• check_email: Check an email address for disposable, relay, spam, role-account and public-provider signals, plus mail setup (MX, SPF, DMARC), domain age and a typo suggestion. Uses 1 credit of your monthly quota.
• check_domain: Check a domain for disposable, relay, spam and public-provider signals, plus mail setup (MX, SPF, DMARC), age, authority and a typo suggestion. Uses 1 credit of your monthly quota.
• get_account_usage: Show the plan name, request rate limit and credits used, remaining and when they reset. The account holder's name and email are not returned by this tool.
• list_blocklist: List the domains on your account's custom blocklist for the key's environment, newest first.
• list_gates: List your gates (allow, block or challenge rule sets) with default action and rule count.
• get_gate: Get one gate by ID: name, environment, default action and rule count.
• list_gate_rules: List a gate's rules in evaluation order with name, action, match mode, enabled flag and conditions.
• get_gate_rule: Get one rule of a gate: name, action, match mode, enabled flag and conditions.
• list_gate_decisions: List a gate's recent decisions with action, deciding rule, domain, country and detected anonymity type. Email addresses and IP addresses are not returned by this tool.

BYOK key

You bring your own UserCheck UserCheck API key (https://www.usercheck.com/docs/api/authentication). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to api.usercheck.com over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

• https://www.usercheck.com/docs/api/introduction (the API this connector calls, with a BYOK key)

Live from the UserCheck API (api.usercheck.com) with a BYOK key; documentation: https://www.usercheck.com/docs/api/introduction. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by UserCheck. UserCheck and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your UserCheck account.

Built for: Worldwide. Languages: English.

UserCheck (BYOK) — Privacy Policy

Effective 24 October 2026. Unify Dynamics LLC ("we", "us"), Menlo Park, California.

What UserCheck (BYOK) is. UserCheck (BYOK) is a connector (an MCP server and REST API) that an AI assistant calls on your behalf to read your own UserCheck data: Check email addresses and domains for disposable, spam, relay and role-account signals, and read your UserCheck blocklist, gates and usage with your own API key. You bring your own UserCheck UserCheck API key; the assistant sends it to us with each request.

BYOK key. The key you supply is used to make the one UserCheck call you asked for. Our application does not store it, write it to a log, put it in a cache, or share it. It is sent only to api.usercheck.com, over https, and is removed from any text we return to you or your assistant. We do not follow redirects with your key. If UserCheck rejects it, we say so without repeating it.

What we receive. The arguments of each tool call, the BYOK key (for that call only), the technical headers needed to serve the request (an IP address or a client identifier supplied by the assistant) and standard server logs. What UserCheck receives. The request we make on your behalf, including the key and the arguments, under UserCheck's own terms and privacy policy. UserCheck acts at your direction and is the only recipient of the data of your request besides our hosting provider.

What we return. The answer UserCheck gives for your request, trimmed to the fields the tool documents. We do not keep it: it is returned to your assistant and not stored, cached or used to train anything.

What we do not do. We do not build a profile, sell or share personal information, or keep your UserCheck data. Rate-limit counters (a client identifier and timestamps) are held in memory for at most 24 hours. Hosting access logs (IP addresses, request paths and status codes) are kept for up to 30 days for security and abuse prevention; our application adds no request headers or bodies to them.

Sub-processors. UserCheck (the API you call with a BYOK key, at your direction). Hosting: Vercel (United States regions).

Your rights. Because we store no personal data beyond short-lived logs, requests to access, correct or delete data are usually satisfied automatically; you can still contact agent@connectorbay.com and we will respond within 30 days. Revoke your key at UserCheck at any time to end all access.

Children. UserCheck (BYOK) is a general-audience service operated by the adult using the assistant, under UserCheck's own age rules.

Changes. We will post changes here with a new effective date.

UserCheck (BYOK) — Terms of Service

Effective 24 October 2026. These terms govern use of the UserCheck (BYOK) connector ("the Service") operated by Unify Dynamics LLC ("we", "us").

1. The Service. UserCheck (BYOK) provides: Check email addresses and domains for disposable, spam, relay and role-account signals, and read your UserCheck blocklist, gates and usage with your own API key. It is accessed through an AI assistant or directly over MCP or HTTP, and is read-only.
2. Your own key, your own account. You must use your own UserCheck credentials and only access data you are allowed to access. UserCheck's terms apply to your use of UserCheck; you are responsible for complying with them, including any rate limits and permitted uses. Do not share a key you do not own.
3. Independent. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by UserCheck. UserCheck and its logos are trademarks of their owners and are used only to say which service the connector works with.
4. No advice, no guarantees. Output is the data UserCheck returns, lightly trimmed; it may be incomplete, delayed or changed by UserCheck. Check important facts at the source.
5. Read-only. The Service does not create, change, send or delete anything in your UserCheck account.
6. Acceptable use. Automated use within the published rate limits is welcome. Do not use the Service to access data you are not entitled to, to circumvent UserCheck's controls, or to attack any system.
7. Availability. The Service is provided "as is" without warranty. We may change, limit or discontinue it at any time; UserCheck may change or end its API at any time.
8. Data. Our Privacy Policy describes what we process. In short: the BYOK key is used for the one call and not stored or logged.
9. Pro keys. Optional ConnectorBay Pro API keys are issued at our discretion and are separate from your UserCheck key.
10. Liability. To the fullest extent permitted by law, Unify Dynamics LLC is not liable for any loss arising from use of or reliance on the Service, including any action UserCheck takes on your account. Our total liability is limited to US $100.
11. Governing law. California law; venue in San Mateo County, California.
12. Contact. Unify Dynamics LLC · agent@connectorbay.com · https://connectorbay.com/byok-usercheck

UserCheck (BYOK) support

Email agent@connectorbay.com. We answer within two business days.

• MCP endpoint: https://byok-usercheck.connectorbay.com/mcp
• REST API: https://byok-usercheck.connectorbay.com/openapi.json
• Live status: https://byok-usercheck.connectorbay.com/health

When you report a problem, include the question you asked your agent, roughly when, and which agent you used (for example Claude, ChatGPT or Gemini). Never send us passwords, account numbers or ID numbers. UserCheck (BYOK) never asks for them.