Lumen

What the lumen MCP server does

The lumen MCP server provides an MCP interface for local SEO audits and selected search and performance reports. Its site audit uses a bounded crawler, respects robots.txt, and applies 36 built-in rules. Results include severity scoring and provenance metadata, so reported metrics identify their source and fetch time.

The package is designed for local, agent-driven workflows rather than a hosted subscription dashboard. It can run as a command-line program or as an MCP process that a coding agent starts over stdio. A Cloudflare Worker transport is also included for the documented gateway deployment.

How it works

The lumen MCP server combines several packages: core models and configuration, an audit package for crawling and rule evaluation, provider implementations for external data, and CLI/MCP packages for execution and transport. The CLI can run an audit directly, while the MCP launcher exposes the same general capabilities to an MCP client.

External metrics come from free services. Supported sources listed by the project include PageSpeed Insights, CrUX, Google Suggest, Wikipedia demand, OpenPageRank, Tranco, and DuckDuckGo SERP. Where a provider requires credentials, lumen follows a bring-your-own-key model: keys are read from environment-variable names and are not stored or logged. If no free source is available for a metric, the project does not return that number.

Audit runs use bounded crawling and accept a page limit from the CLI. The command-line interface can also emit JSON and uses exit codes that distinguish a passing run, findings, and usage or aborted runs.

Setup and configuration

Node.js 22.7 or newer is required for the quickstart, with the development section specifying Node 22 or newer. Run an audit without a global installation with npx -y @lumen-seo/cli audit https://example.com, or install the CLI globally using npm install -g @lumen-seo/cli and invoke lumen audit.

To use the MCP interface with Claude Code, register the stdio process with:

claude mcp add --transport stdio lumen -- npx -y @lumen-seo/cli mcp

The documentation also covers Cursor and VS Code onboarding. Provider credentials, when applicable, are supplied through environment variables; the provided material does not list the individual variable names.

Tools and capabilities

The lumen MCP server exposes five tools:

• lumen_audit_site runs a site audit.
• lumen_page_report produces a page-level report.
• lumen_keyword_ideas retrieves keyword ideas from the supported providers.
• lumen_rank_check checks rankings through the available SERP provider.
• lumen_authority reports authority-related data.

The audit package contains 36 built-in rules. The provider set includes performance and demand sources, plus OpenPageRank and Tranco for authority or popularity-related data. Every returned metric carries source and fetch-timestamp information according to the project description.

Limitations and notes

The project is at version 0.2.x and is described as its first public release. It relies on free data services, so provider availability and rate limits can affect which reports are available. API credentials are not bundled; users must provide their own keys where a provider requires them.

The crawler is bounded rather than unrestricted, and the CLI documents a --max-pages option. MCP use requires a compatible client and either the stdio launcher or the documented remote gateway. The README identifies the CLI, five MCP tools, and documentation as available, but does not claim support for additional SEO data sources beyond those listed.