ListSignal

What ListSignal MCP server does

ListSignal MCP server exposes business and sales intelligence from ListSignal to MCP-compatible AI clients. The data covers more than 16 million online businesses and includes technology detection, Shopify app detection, company and domain enrichment, estimated revenue and employee counts, hiring signals, SEO scores, traffic rank, and contact information on eligible paid plans.

The server supports two main research patterns. You can search for companies matching criteria such as technology, Shopify app, country, business model, revenue bracket, or hiring status. You can also provide one domain to retrieve the available information for that company. Results from company searches are traffic-ranked and capped at 100 companies per call.

How it works

The hosted endpoint is available at https://listsignal.com/mcp using remote Streamable HTTP, so a local package is not required for clients with native HTTP MCP support. Requests authenticate with a bearer API key in the Authorization header; the API also accepts an X-API-Key header.

ListSignal discovers businesses through Certificate Transparency logs, which helps newly launched companies enter the dataset within hours. It then enriches domains using technology detection covering more than 230 technologies, Shopify app detection covering more than 260 apps, firmographic estimates, job data from more than 14,000 job boards, SEO scoring, and published contact data. Hiring records include posting dates and a hiring breakdown.

Setup and configuration

Create an account and API key through ListSignal Settings, then configure the MCP endpoint in the client. A native HTTP configuration uses the endpoint URL and an Authorization: Bearer ls_YOUR_KEY header. Claude Desktop, Claude Code, and Cursor examples are provided in the project documentation.

For clients without native HTTP support, the documented approach uses the mcp-remote package through npx as a stdio bridge. The bridge forwards requests to the same hosted endpoint and supplies the authorization header. The equivalent Claude Code command uses claude mcp add with HTTP transport.

The free plan allows 1,000 calls per month. Listed paid quotas are 5,000 calls per month for Starter and 25,000 for Pro. Rate limits are 30, 60, or 120 calls per minute depending on the plan, and only successful calls count toward the quota.

Tools and capabilities

ListSignal MCP server provides these tools:

• listsignal_search_companies combines supported filters with AND logic and returns up to 100 traffic-ranked companies. Filters cover technology, Shopify app, country, business model, revenue bracket, and hiring status.
• listsignal_get_company returns available information for a domain, including technologies, Shopify apps, revenue and employee estimates, open jobs, hiring details, SEO score, traffic rank, and contact emails where the plan permits them.
• listsignal_dataset_stats returns live, citable dataset statistics. The dataset statistics are refreshed every 60 seconds.

The same underlying data is also available through ListSignal's REST API, with developer documentation and an OpenAPI 3.1 specification.

Limitations and notes

Contact emails are available on paid plans; free accounts receive contactability information and counts instead. Search results are limited to 100 companies per call, so broader research may require multiple requests while respecting quota and rate limits.

Tool errors are returned in-band with actionable messages, allowing an agent to correct a request and retry once. The available data is based on detection and estimation methods, including estimated revenue and employee figures, so these fields should be treated as dataset estimates rather than verified financial statements.