mcp-protocol

name	mcp-protocol
description	MCP JSON-RPC 2.0 protocol reference for WordPress tools
user-invocable	false

MCP Protocol Reference — WordPress

Overview

MCP (Model Context Protocol) uses JSON-RPC 2.0 over HTTP.

• Endpoint: POST /mcp
• Content-Type: application/json
• Auth: Via headers (multi-tenant) or env (single-tenant)

Authentication Headers

For multi-tenant mode, send credentials per request:

x-wordpress-url: https://wp.example.com
x-wordpress-username: admin
x-wordpress-password: ApplicationPasswordNoSpaces

Standard Methods

tools/list

{
  "jsonrpc": "2.0",
  "method": "tools/list",
  "id": 1
}

Response:

{
  "jsonrpc": "2.0",
  "result": {
    "tools": [
      {
        "name": "wp_get_posts",
        "description": "List WordPress posts",
        "inputSchema": { ... }
      }
    ]
  },
  "id": 1
}

tools/call

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "wp_get_posts",
    "arguments": { "per_page": 10 }
  },
  "id": 2
}

Response:

{
  "jsonrpc": "2.0",
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"count\": 10, \"posts\": [...]}"
      }
    ]
  },
  "id": 2
}

Error Codes

Standard JSON-RPC

Code	Meaning
-32700	Parse error
-32600	Invalid request
-32601	Method not found
-32602	Invalid params
-32603	Internal error

Custom MCP Errors

Code	Meaning
-32001	No credentials provided
-32002	Invalid credentials
-32003	WordPress API error
-32004	Tool not found
-32005	Validation error

Tool Schema Pattern

{
  name: "wp_create_post",
  description: "Create a new WordPress post",
  inputSchema: {
    type: "object",
    properties: {
      title: { type: "string", description: "Post title" },
      content: { type: "string", description: "Post content (HTML)" },
      status: {
        type: "string",
        enum: ["draft", "publish", "pending", "private"],
        description: "Post status (default: draft)"
      }
    },
    required: ["title", "content"]
  }
}

Content Types

type Content =
  | { type: 'text'; text: string }
  | { type: 'image'; data: string; mimeType: string }
  | { type: 'resource'; resource: { uri: string; text: string } };