LookupLab

What the LookupLab MCP server does

The LookupLab MCP server exposes four account-backed lookup tools over MCP. phone_lookup returns carrier and line-type information, with optional caller-name data. email_verify checks syntax, MX records, and domain indicators. ip_lookup provides approximate location and network information. dns_check queries mail and authentication records, including MX, SPF, DMARC, or DKIM.

These checks are intended for validating or investigating contact and network data. Results do not prove a person’s identity, ownership of a resource, consent to contact, guaranteed email delivery, or precise physical location. Privacy-related flags may also be unavailable.

How it works

The LookupLab MCP server uses Streamable HTTP at https://lookuplab.io/api/mcp. Responses are JSON-based, and the service does not use an SSE stream. Clients can authenticate with a bearer token or an X-API-Key header containing a LookupLab API key.

Each successful lookup deducts credits from the connected account. A phone lookup costs one credit for landline, VoIP, or toll-free numbers, and three credits for mobile or unknown numbers; requesting caller-name information adds two credits. Email, IP, and DNS checks cost one credit each. The account must have enough balance for the maximum possible charge before a request begins. Failed or invalid results are not charged.

Because tools debit credits, they are treated as operations with side effects. Retried requests can charge again unless the client sends a stable Idempotency-Key header. Submit only information you are authorized to check.

Setup and configuration

For clients that support remote MCP connections, add https://lookuplab.io/api/mcp and provide authentication in the client’s secure connection settings. The service accepts either Authorization: Bearer YOUR_API_KEY or X-API-Key: YOUR_API_KEY.

Claude web and Desktop can add LookupLab as a custom connector, then complete the LookupLab consent flow with a key from the LookupLab dashboard. Claude Team and Enterprise deployments require an owner to add the connector before members connect their own accounts.

Claude Code can use the HTTP configuration in the repository’s claude-code.mcp.json. Set LOOKUPLAB_API_KEY in the environment, merge the configuration into the project’s .mcp.json, and approve the server when Claude Code prompts you. Keep the variable reference rather than placing a real key in a shared file.

Gemini CLI installs the extension from the repository URL and stores the API key in its sensitive setting. The repository also contains a portable plugin package for ChatGPT and Codex, but its OAuth connection requires an exact callback registered by LookupLab.

Tools and capabilities

• phone_lookup: Checks carrier and line type; optionally requests caller name.
• email_verify: Checks email syntax, MX records, and domain indicators.
• ip_lookup: Returns approximate location and network details.
• dns_check: Checks MX, SPF, DMARC, or DKIM records.

The LookupLab MCP server is a fit for agent workflows that need account-metered checks against phone, email-domain, IP-network, or DNS data. It is less suitable when a workflow requires identity proof, guaranteed deliverability, exact geolocation, or zero-cost retries.