Millionverifier

What Millionverifier MCP server does

Millionverifier MCP server exposes MillionVerifier’s single-email verification endpoint through MCP. The primary tool, millionverifier_verify, checks one address at a time and returns the provider’s verification result along with fields such as quality, free-provider status, role-address status, and a derived catch_all boolean.

Possible provider results include ok, catch_all, disposable, invalid, and unknown. The source material also documents unverified and error as values surfaced by the provider or verification checks. This integration is intended for agents that need an email verification step inside an enrichment, signup, lead-processing, or contact-cleaning workflow.

How it works

The tool sends a GET request to https://api.millionverifier.com/api/v3/. The email address and API key are passed as query parameters: email contains the address being checked, while api contains the MillionVerifier key supplied through the _apiKey tool argument. A timeout can be provided as an optional tool argument.

The implementation does not rely only on the HTTP status code. MillionVerifier can return HTTP 200 when authentication fails, with a payload containing result: "error" and an error message such as Apikey not found. The integration detects that response shape and raises the call error instead of treating it as an email verdict. For normal responses, it derives catch_all from whether the provider result equals catch_all.

Setup and configuration

Millionverifier MCP server supports a hosted Pipeworx connection and a standalone local process. For the hosted option, configure an MCP client with the streamable HTTP URL https://gateway.pipeworx.io/millionverifier/mcp. The README names Claude Desktop, Cursor, and Windsurf as example clients.

The local option runs with npx -y @pipeworx/mcp-millionverifier and communicates over standard input and output. It does not require a Pipeworx account or gateway round trip. The local process exposes only this package’s tools, while the hosted endpoint also lists shared Pipeworx meta-tools.

Authentication is bring-your-own-key. Obtain the key from the MillionVerifier API page and provide it as _apiKey when calling the verification tool. No platform key is supplied by the integration, and no environment variable is documented as required.

Tools and capabilities

• millionverifier_verify(email, timeout?, _apiKey): verifies one email address.
• Returns the provider result, including statuses such as valid, invalid, disposable, catch-all, or unknown where reported.
• Provides a stable boolean catch_all field derived from the provider result.
• Includes quality, free-provider, and role-address indicators.
• Supports hosted MCP access through Pipeworx or local stdio execution.

Limitations and notes

Millionverifier MCP server is an unofficial integration and is not affiliated with, endorsed by, or published by MillionVerifier. It verifies one address per tool call through the single-verify API; the material does not describe bulk verification capabilities.

The full mapping between MillionVerifier resultcode values and result labels has not been verified. Provider behavior can also include an error result that represents a failed API call rather than a classification of the email address. Hosted pack endpoints include shared gateway tools in addition to the package tool, whereas the standalone process does not include those gateway-wide tools.