LayerCall

Score an IP, email, phone, domain or device for fraud in one call, with the signals behind it.

CommunityOnlineAPI key requiredGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    An API key from the service settings is required

    Score an IP, email, phone, domain or device for fraud in one call, with the signals behind it.

    How to connect

    How to connect LayerCall to Claude

    The server address to paste into Claude settings:

    https://www.layercall.com/api/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect LayerCall to ChatGPT

    The server address to paste into ChatGPT settings:

    https://www.layercall.com/api/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect LayerCall to Cursor

    The server address to paste into Cursor settings:

    https://www.layercall.com/api/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (7)

    Raw names from tools/list. Only developers need these.

    score_ipRisk-score an IPv4 or IPv6 address. Detects commercial VPNs (naming the provider where its own published list confirms it), proxies, Tor exit nodes and datacenter hosting, and returns geolocation, ASN and a 0-100 risk score with an allow/review/block verdict.
    verify_emailCheck an email for syntax, MX records, disposable/throwaway providers, role accounts (info@, admin@), homograph lookalikes and domain age. Returns a 0-100 risk score and an allow/review/block verdict.
    lookup_phoneValidate a phone number worldwide against its national numbering plan. Returns E.164, country, line type (mobile/fixed/VoIP/toll-free/premium) and a risk score. Works globally, not US-only.
    score_domainProfile a domain: registration date from RDAP, registrar, MX/SPF/DMARC configuration, disposable-mail and risky-TLD detection. newly_registered is null when the age genuinely could not be determined — treat that as unknown, not as 'established'.
    score_deviceJudge a browser fingerprint from /fp.js: headless detection, automation frameworks (Selenium, Puppeteer, Playwright), timezone-versus-IP mismatch and repeat-device history. Note the ceiling honestly — the declared signals it relies on are the first thing stealth tooling patches, so a clean result is weaker evidence than a dirty one.
    verify_agentCryptographically verify a Web Bot Auth signature (RFC 9421) — proof of WHICH agent is calling, not a guess from the user-agent. Returns verified true/false plus the agent's identity and declared purpose. This is the only check here that proves rather than infers, so it carries no score and no verdict: a verified assistant acting for a real user is usually welcome, a verified scraper usually is not, and that policy is the caller's. Pass the request the agent made to YOU — the signature covers its method, authority and path.
    score_userScore an entire signup in one call — any combination of IP, email, phone and domain — returning a single weighted risk score, a verdict, and the top contributing signals. A hard block on any component is never averaged away. This is the tool to use when judging a person rather than a value. Costs one lookup PER COMPONENT supplied, not one per call, so four identifiers cost four; the response reports the exact figure as billable_lookups, and cached components are refunded.