Quackr MCP Server

Official MCP server for Quackr — virtual phone numbers for SMS verification and OTP receipt. Use Claude (or any MCP-compatible client) to check pricing and inventory, purchase temporary numbers, and read incoming SMS programmatically.

• npm: quackr-mcp — npx -y quackr-mcp
• Hosted endpoint: https://mcp.quackr.io/
• Transport: Streamable HTTP
• Auth: Authorization: Bearer YOUR_API_KEY header

Tools

Tool	Description
get-balance	Get the current account balance in USD
get-pricing	Get phone number rental pricing for a specific country
get-inventory	Check available phone number inventory for a country
purchase-number	Purchase a temporary number for receiving SMS (deducts from balance)
check-sms	Check SMS messages received on a rented number
list-active-numbers	List all currently active (rented) numbers on the account

Getting an API Key

1. Sign in at quackr.io
2. Open your profile page
3. Copy the API key from the API section

Install via npm

The quackr-mcp package is a thin stdio launcher that bridges any stdio MCP client to the hosted Quackr endpoint. It needs Node.js 18+ — no separate install required, npx fetches it on first run.

{
  "mcpServers": {
    "quackr": {
      "command": "npx",
      "args": ["-y", "quackr-mcp"],
      "env": {
        "QUACKR_API_KEY": "YOUR_API_KEY_HERE"
      }
    }
  }
}

You can also pass the key as a flag instead of an env var: npx -y quackr-mcp --api-key YOUR_API_KEY_HERE.

Claude Code Setup

Remote (recommended) — connect directly to the hosted endpoint. Add to your ~/.claude.json (or a project .mcp.json):

{
  "mcpServers": {
    "quackr": {
      "type": "http",
      "url": "https://mcp.quackr.io/",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY_HERE"
      }
    }
  }
}

Or via the CLI:

claude mcp add --transport http quackr https://mcp.quackr.io/ --header "Authorization: Bearer YOUR_API_KEY_HERE"

Claude Desktop Setup

Claude Desktop's JSON config only supports local (stdio) servers. Use the npm launcher (see Install via npm) by adding the npx quackr-mcp config above to claude_desktop_config.json, then restart Claude Desktop.

Alternatively, add Quackr as a remote connector: Settings → Connectors → Add custom connector, enter https://mcp.quackr.io/, and add an Authorization header with the value Bearer YOUR_API_KEY.

Other MCP Clients

Any client supporting remote Streamable HTTP MCP servers with custom headers works. Point it at https://mcp.quackr.io/ and pass your key via the Authorization: Bearer YOUR_API_KEY header.

REST API

Quackr also exposes a full REST API at https://api.quackr.io/ — see api.quackr.io/swagger.json for the full spec. Same x-api-key auth.

Support

• Website: quackr.io
• Issues: file in this repo
• Email: support@quackr.io

License

MIT — see LICENSE.