# MCP Server — BigFat AI Labs

Connect BigFat AI Labs to Claude, Cursor, and any Model Context Protocol client. Fifteen tools for transactional email, contacts, segments, and campaigns.

[Get started free](https://email-bulk-app.bigfat.ai/auth/signup) | [Documentation](https://email-bulk-docs.bigfat.ai/guides/mcp-server)

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## Setup

The server is published as `@bigfat/mcp`. You need a secret key (`sk_…`) from Settings → API Keys.

```bash
claude mcp add bigfat --env BIGFAT_API_KEY=sk_your_key -- npx -y @bigfat/mcp
```

For Claude Desktop, Cursor, or any other client, add it to your MCP config:

```json
{
  "mcpServers": {
    "bigfat": {
      "command": "npx",
      "args": ["-y", "@bigfat/mcp"],
      "env": {
        "BIGFAT_API_KEY": "sk_your_key"
      }
    }
  }
}
```

Self-hosting? Set `BIGFAT_API_URL` to your own API domain.

## Tools

**Read-only** — the only tools registered when `BIGFAT_READ_ONLY=true`: `bigfat_list_contacts`, `bigfat_get_contact`, `bigfat_verify_email`, `bigfat_list_templates`, `bigfat_list_campaigns`, `bigfat_list_segments`

**Writing**: `bigfat_create_contact`, `bigfat_update_contact`, `bigfat_delete_contact`, `bigfat_send_email`, `bigfat_track_event`, `bigfat_create_template`, `bigfat_create_campaign`, `bigfat_send_campaign`, `bigfat_create_segment`

## Safety

- **Sends ask you first.** Sending a campaign, or an email to more than one recipient, prompts you and shows the recipient count. The confirmation comes from you through your MCP client, not from the model.
- **Read-only mode is structural.** With `BIGFAT_READ_ONLY=true` the mutating tools are never registered, so they cannot be invoked at all.
- **Account actions are out of reach.** Billing, project deletion, and key rotation require a dashboard session, so no tool can touch them.

[Back to features](/features) | [Pricing](/pricing) | [Documentation](https://email-bulk-docs.bigfat.ai/guides/mcp-server)