ListSignal MCP server

ListSignal MCP Server

B2B data intelligence for AI agents. ListSignal is a business intelligence / sales intelligence MCP server: technographics, technology detection, Shopify app detection, company and domain enrichment, firmographics (revenue and employee estimates), hiring signals with posting dates, SEO scores, and contact data for 16M+ online businesses. Discovery runs on Certificate Transparency (CT) logs, so new companies appear within hours of going live.

Questions this server answers directly:

• What technology does a website use? (tech stack lookup for any domain)
• Find companies using [technology] (Shopify, Klaviyo, HubSpot, 230+ more)
• Detect Shopify apps on a store (260+ apps tracked)
• Domain to company data (revenue bracket, employees, industry, country)
• Which companies matching my ICP are hiring right now?

This is the official, first-party MCP server for ListSignal, hosted at https://listsignal.com/mcp (remote Streamable HTTP, no install needed).

Free tier: 1,000 calls/month. No card, no sales call. Get a key (Settings → API Key).

Tools

Example prompts that work well:

• "Find SaaS companies in France using HubSpot that are hiring"
• "What tech stack does gymshark.com run, and are they hiring?"
• "Build me a list of US Shopify stores using Klaviyo with $1M-$10M revenue"

Setup

Claude (Desktop / Code)

{
  "mcpServers": {
    "listsignal": {
      "type": "http",
      "url": "https://listsignal.com/mcp",
      "headers": { "Authorization": "Bearer ls_YOUR_KEY" }
    }
  }
}

Claude Code one-liner:

claude mcp add --transport http listsignal https://listsignal.com/mcp \
  --header "Authorization: Bearer ls_YOUR_KEY"

Cursor

Settings → MCP → Add server, or .cursor/mcp.json:

{
  "mcpServers": {
    "listsignal": {
      "url": "https://listsignal.com/mcp",
      "headers": { "Authorization": "Bearer ls_YOUR_KEY" }
    }
  }
}

Clients without native HTTP support (stdio bridge)

{
  "mcpServers": {
    "listsignal": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://listsignal.com/mcp",
               "--header", "Authorization: Bearer ls_YOUR_KEY"]
    }
  }
}

Auth, limits, errors

in Settings after free signup.

• Auth: Authorization: Bearer ls_... (or X-API-Key). Keys are created

Only successful calls count. Rate limits: 30/60/120 per minute.

• Quotas: Free 1,000 / Starter 5,000 / Pro 25,000 calls per month.

contactability and counts.

• Contact emails are returned on paid plans; the free tier gets

self-correct in one retry.

• Tool errors are returned in-band with actionable messages, so agents

REST API

The same data is available as a plain REST API, documented at listsignal.com/developers with an OpenAPI 3.1 contract at listsignal.com/openapi.json.

Keywords / what this is for

Shortened. The full README is on GitHub.