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Quackr

Official registry Security

Virtual phone numbers for SMS verification, OTP receipt, and number management.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http quackr 'https://mcp.quackr.io/' --header 'Authorization: <Bearer token in the form '\''Bearer <your Quackr API key>'\'', from your profile page at quackr.io>'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "quackr": {
            "type": "http",
            "url": "https://mcp.quackr.io/",
            "headers": {
                "Authorization": "<Bearer token in the form 'Bearer <your Quackr API key>', from your profile page at quackr.io>"
            }
        }
    }
}
NPM package quackr-mcp
Claude Code 
claude mcp add quackr -e 'QUACKR_API_KEY=<your quackr_api_key>' -- npx -y quackr-mcp@1.0.1
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "quackr": {
            "command": "npx",
            "args": [
                "-y",
                "quackr-mcp@1.0.1"
            ],
            "env": {
                "QUACKR_API_KEY": "<your quackr_api_key>"
            }
        }
    }
}

Environment variables

  • QUACKR_API_KEY required secret Your Quackr API key, from your profile page at quackr.io

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Quackr MCP Server
  2. Tools
  3. Getting an API Key
  4. Install via npm
  5. Claude Code Setup
  6. Claude Desktop Setup
  7. Other MCP Clients
  8. REST API
  9. Support
  10. License

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

ToolDescription
get-balanceGet the current account balance in USD
get-pricingGet phone number rental pricing for a specific country
get-inventoryCheck available phone number inventory for a country
purchase-numberPurchase a temporary number for receiving SMS (deducts from balance)
check-smsCheck SMS messages received on a rented number
list-active-numbersList 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.

Frequently asked questions

What is Quackr?

Virtual phone numbers for SMS verification, OTP receipt, and number management.

How do I install Quackr?

It runs as a remote server. In Claude Code: claude mcp add --transport http quackr 'https://mcp.quackr.io/' --header 'Authorization: <Bearer token in the form '\''Bearer <your Quackr API key>'\'', from your profile page at quackr.io>'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Quackr need an API key?

Yes. It expects QUACKR_API_KEY, Authorization, which you set in its configuration.

Is Quackr open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Quackr?

It is published by quackr-mcp. AI.tn lists it but does not maintain or endorse it.

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