Claude MCP: how to connect Claude to live B2B data

Ask Claude who runs sales at one of your target accounts and it answers from memory: the org chart as it was when its training data ends, and no work email at all. An MCP server changes that. Add one URL to Claude, sign in, and Claude can look up live companies, people, verified work emails and job postings while you chat.

This guide shows how, step by step, with the BlitzAPI MCP server. MCP is one of the ways AI agents use BlitzAPI, next to the API and Agent Skills; the agentic commerce guide covers the newest one, agents that buy the data on their own.

Why can’t Claude look up live B2B data on its own?

Because a model answers from what it learned in training, and org charts change every week. People change jobs, get promoted and leave: the VP of Sales a model remembers may be gone. And a verified work email is not something a model can recall. It has to be checked against the company’s mail server, today.

A web search can turn up a name. It can’t give you a work email that has been proven to work, and it won’t build a list of 200 accounts for you. For that, the assistant needs a live data source it can call.

What is an MCP server?

An MCP server is the plug between an AI assistant and a live system. It tells the assistant which tools it offers and what each one does; the assistant calls them when a question needs them, and the answer comes back into the conversation.

Definition MCP server also called Model Context Protocol server

A connector that gives an AI assistant tools it can use: it tells the assistant what each tool does, and the assistant calls them during a conversation to read data or take an action.

PreciselyAn MCP server exposes tools, resources and prompts to AI applications over the Model Context Protocol, an open standard introduced by Anthropic in November 2024 and donated in December 2025 to the Agentic AI Foundation, a directed fund of the Linux Foundation. A remote MCP server is reached by URL and usually signs the user in with OAuth.

MCP stands for Model Context Protocol. It is an open standard, so one server works in several AI tools: Claude, Claude Code, Cursor and VS Code all take the same address. In the BlitzAPI MCP server, each tool runs one BlitzAPI endpoint, with the same parameters and the same answer as the API.

What is a Claude connector?

A connector is how Claude plugs into an outside service. Some come from Anthropic’s directory; a custom connector is one you add yourself, by pasting the URL of a remote MCP server.

Definition Claude connector also called custom connector

An outside tool or data source plugged into Claude, so Claude can read from it or act in it while you chat. A custom connector is one you add yourself by pasting the URL of a remote MCP server.

PreciselyIn Claude, connectors link the assistant to external services: some come from Anthropic's directory, and custom connectors are remote MCP servers added by URL. Custom connectors are available on the Free plan (one at a time), Pro, Max, Team and Enterprise; on Team and Enterprise, an owner adds them for the organization first.

Custom connectors work on every Claude plan: Free (one at a time), Pro, Max, Team and Enterprise. On Team and Enterprise, an owner adds the connector for the organization first, then each person connects it with their own account. Claude reaches the server from Anthropic’s cloud, so the server has to be public, which the BlitzAPI one is.

How do you set up Claude MCP for B2B data?

In three steps: get a BlitzAPI account, add the server as a custom connector, then switch it on in a chat.

1. Get a BlitzAPI account. Every account starts with 1,000 free records, no card.
2. Add the connector. In Claude, open Customize, then Connectors. Click Add, choose Add custom connector, name it BlitzAPI, paste https://api.blitz-api.ai/mcp and click Continue. Keep the detected sign-in settings, choose Sign in now, click Add, and log in with your BlitzAPI account in the window that opens. There is no API key to copy.
3. Switch it on and ask. In a chat, click the + button, open Connectors and turn BlitzAPI on. Then ask in plain words.

Claude Code, Cursor, VS Code and Claude Desktop take the same URL; their setup is in the builders section at the end of this guide.

What can you ask Claude once it has live B2B data?

Anything a prospect list or an account brief needs, in plain words. A few questions to start with, and the BlitzAPI endpoints each one runs:

• “Find 25 VPs of Marketing at B2B SaaS companies in the US with 50 to 200 employees. Show name, title, company and profile URL in a table.” Claude runs a People Search.
• “Using BlitzAPI, find the Head of Sales at acme.com and get their work email.” Claude chains Domain to LinkedIn, Waterfall ICP and Email Enrichment.
• “Which companies headquartered in Texas are hiring SDRs right now?” Claude turns job postings into an account list with TAM by Jobs.
• “How many records do I have left on my BlitzAPI plan?” Claude checks your account, which uses no records.

What happens when Claude calls the MCP server?

Claude splits your question into tool calls, each one a call to the API, then writes the answer from what comes back. We ran the second question on October 16, 2026, with the BlitzAPI MCP server, on a real company instead of acme.com. The company and the person found are withheld.

The first call found the company page from the domain. The second searched that company with a cascade of sales titles (Head of Sales or Chief Revenue Officer first, then VP of Sales, then Sales Director) and found a Chief Revenue Officer at the first level: the method the decision makers guide explains. The third looked for a work email it could prove, found none, and said so.

How many records does a question use?

As many as the items it returns. A record is one company, one person, one email address, one phone number or one job posting, and a call that finds nothing counts nothing. The run above used two: one company and one person.

Each tool result reports the records it used, and tool calls run on your BlitzAPI plan exactly like API calls. Checking your plan or reading the changelog uses no records. For a pull of thousands of rows, ask Claude for a script that calls the API rather than one giant tool call: the rows land in a file instead of filling the chat. Plans are on the BlitzAPI pricing page.

Can ChatGPT, Cursor and VS Code use the same MCP server?

Cursor and VS Code, yes: they take the same URL and open the same sign-in. ChatGPT accepts custom MCP servers in Business, Enterprise and Edu workspaces, on the web: an admin or owner adds the server from Plugins, with Add custom MCP server, then people in the workspace select it with @ in a chat. The BlitzAPI setup guide covers Claude, Claude Code, Cursor, VS Code and Claude Desktop.

Is it safe to connect Claude to a data MCP server?

Yes, with the care any connection to your accounts deserves. Sign-in goes through OAuth: you log in on BlitzAPI’s page, and Claude never sees your password. Anthropic doesn’t review custom connectors, so connect only servers you trust; the official BlitzAPI server lives at api.blitz-api.ai/mcp, run by BlitzAPI. If you use an API key instead, treat it like a password and keep it out of any file you share or commit.

claude mcp add --transport http blitz-api https://api.blitz-api.ai/mcp

claude mcp add --transport http blitz-api https://api.blitz-api.ai/mcp \
  --header "x-api-key: YOUR_API_KEY"

{
  "mcpServers": {
    "blitz-api": {
      "url": "https://api.blitz-api.ai/mcp"
    }
  }
}

{
  "servers": {
    "blitz-api": {
      "type": "http",
      "url": "https://api.blitz-api.ai/mcp"
    }
  }
}

{
  "company_linkedin_url": "https://www.linkedin.com/company/<company>",
  "cascade": [
    {
      "include_title": ["Head of Sales", "[Chief Revenue Officer]",
                        "[CRO]"],
      "exclude_title": ["assistant", "intern"]
    },
    {
      "include_title": ["VP Sales", "Vice President Sales",
                        "Vice President of Sales"],
      "exclude_title": ["assistant", "intern"]
    },
    {
      "include_title": ["Sales Director", "Director of Sales"],
      "exclude_title": ["assistant", "intern"]
    }
  ],
  "max_results": 1
}