MCP Authentication & Endpoint Reference

For ability details see the ability reference docs and for step-by-step walkthroughs see the tutorials.

Endpoint

POST https://example.com/wp-json/mcp/mcp-adapter-default-server

Replace example.com with your site domain. The path is fixed by the WordPress MCP Adapter plugin.

Authentication

All requests use HTTP Basic auth with a WordPress Application Password:

Authorization: Basic base64(username:application-password)

Generate an Application Password in Users → Profile → Application Passwords in the WordPress admin.

# Convenience: pass credentials with -u; curl handles the base64 encoding.
curl -u "username:xxxx xxxx xxxx xxxx xxxx xxxx" ...

Required Permissions

Capability	Needed for
upload_files	Listing folders, adding/removing media, read-only abilities
manage_categories	Creating, updating, or deleting folders; archiving media
manage_options	Rules, media cleanup actions, AI Organizer scan

Administrators have all three. You can create a dedicated lower-privilege user with only upload_files + manage_categories for read/write folder operations without site-wide admin access.

Request Format

Every call uses JSON-RPC 2.0 over HTTP POST:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "mcp-adapter-execute-ability",
    "arguments": {
      "ability_name": "<ability-name>",
      "parameters": { }
    }
  }
}

Content-Type: application/json

Response Format

Successful response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": { "content": [ { "type": "text", "text": "..." } ] }
}

The ability result is JSON-encoded inside result.content[0].text.

Error response (ability returned WP_Error, or JSON-RPC error):

{
  "jsonrpc": "2.0",
  "id": 1,
  "error": { "code": -32000, "message": "Ability execution failed: ..." }
}

Discovering Available Abilities

To list all registered abilities on a site:

curl -s -X POST "https://example.com/wp-json/mcp/mcp-adapter-default-server" \
  -u "username:xxxx xxxx xxxx xxxx xxxx xxxx" \
  -H "Content-Type: application/json" \
  -d '{ "jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {} }'

Only abilities with meta.mcp.public = true are exposed. All abilities registered by VMFA AI Ability include this flag.

Client Configuration

Claude Desktop

{
  "mcpServers": {
    "vmfo": {
      "type": "http",
      "url": "https://example.com/wp-json/mcp/mcp-adapter-default-server",
      "headers": {
        "Authorization": "Basic <base64(username:application-password)>"
      }
    }
  }
}

GitHub Copilot in VS Code

1. Open Command Palette.
2. Run MCP: Add Server.
3. Choose HTTP server.
4. Use endpoint https://example.com/wp-json/mcp/mcp-adapter-default-server.
5. Add Basic auth header for your Application Password user.

Cursor

{
  "mcpServers": {
    "vmfo": {
      "url": "https://example.com/wp-json/mcp/mcp-adapter-default-server",
      "headers": {
        "Authorization": "Basic <base64(username:application-password)>"
      }
    }
  }
}

Troubleshooting

Symptom	Likely cause
401 or 403	Wrong Application Password or user lacks required capability
Tool not found	mcp-adapter-execute-ability not listed in tools/list — check adapter plugin is active
Folder mismatch	Resolve folders by path, not just name
Upload OK but assignment failed	Confirm the media ID is an attachment post and folder ID exists

Smoke Test

MCP_BASE_URL="https://example.com/wp-json/mcp/mcp-adapter-default-server" \
MCP_USER="per" \
MCP_APP_PASS="xxxx xxxx xxxx xxxx xxxx xxxx" \
./scripts/mcp-adapter-smoke-test.sh

Add VMFO_RUN_MUTATING_TESTS=1 to enable write-operation tests (creates and deletes a test folder).

Skill: Auto-Place Photos By Image Content

A reusable agent skill is available at .github/skills/add-photo-to-folder/SKILL.md. It implements the full upload → suggest → create → assign flow described in Tutorial 101.