The Stax Docs Model Context Protocol (MCP) server lets AI-powered editors like Cursor and Windsurf — plus general-purpose assistants like Claude — search the Stax documentation and execute real Stax API endpoints on your behalf.

Searching the docs works out of the box with no setup. Executing endpoints requires you to add your own Merchant or Partner API key to your MCP client's configuration, which is what most of this page covers.

What is MCP?

Model Context Protocol (MCP) is an open standard that allows AI applications to securely access external data sources and tools. The Stax Docs MCP server gives your AI assistant these tools:

Quick Start (Docs Only)

Stax hosts a remote MCP server at https://docs.staxpayments.com/mcp. The server is public, so this configuration alone gives your assistant full access to search and read the documentation.

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp"
    }
  }
}

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp"
    }
  }
}

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp"
    }
  }
}

claude mcp add --transport http staxapi https://docs.staxpayments.com/mcp

If you try to run an endpoint before adding a key, the execute-request tool refuses the call and returns a Missing Security Schemes error naming the key type that endpoint requires.

Executing Endpoints With Your API Key

Any header you set on the MCP server in your client configuration is forwarded by execute-request to the Stax API on every request. Adding an Authorization header is therefore all it takes to let your assistant enroll merchants, create customers, run transactions, and pull reports directly from your editor.

Step 1: Choose the Right Key

Stax endpoints are secured by one of two key types. Which one you need depends entirely on which endpoints you intend to run.

Step 2: Get Your Key

Step 3: Add the Key to Your Configuration

Add a headers object to your server entry and set Authorization to Bearer followed by your key.

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

{
  "mcpServers": {
    "staxapi": {
      "url": "https://docs.staxpayments.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

claude mcp add --transport http staxapi https://docs.staxpayments.com/mcp --header "Authorization: Bearer YOUR_API_KEY"

Restart your editor or assistant after saving so it reconnects with the new header.

Step 4: Register Both Keys as a Partner

Each MCP server entry forwards exactly one Authorization header. Because partner developers need the Partner API for enrollment and the Merchant API for everything else, register the server twice under different names — one entry per key.

{
  "mcpServers": {
    "stax-partner": {
      "url": "https://docs.staxpayments.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_PARTNER_API_KEY"
      }
    },
    "stax-merchant": {
      "url": "https://docs.staxpayments.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_MERCHANT_API_KEY"
      }
    }
  }
}

Your assistant then picks the entry that matches the endpoint. Name the entries clearly — stax-partner and stax-merchant are far easier for an assistant to route correctly than staxapi and staxapi2.

Step 5: Verify Your Setup

Start a new chat in your AI tool and confirm each layer works:

1. Docs search — "What ACH error codes does Stax return?"
2. Endpoint lookup — "Use get-endpoint to show me the fields required to create a customer."
3. Live execution — "List the customers on my account." A successful call returns real data from your account. A Missing Security Schemes error means the header is not reaching the server.

Once execution is working, you can ask your assistant to chain steps end to end — for example, "Enroll a test merchant, create a customer on it, tokenize a card, and run a $1.00 sale."

Troubleshooting

Next Steps