How To: Connect OpenCode to WordPress with MCP (100% Free)

I wanted to see how far you can go with WordPress and an AI agent without spending a single cent. The answer: all the way 😊 OpenCode is free and open source, it comes with free AI models, and the MCP server in AI Engine is free too. Put them together and an agent in your terminal writes posts, sorts categories and looks after your site. No account, no API key, no credit card.

I tested every step below on a real site running the free version of AI Engine, with nothing paid anywhere. If you prefer Claude Code, I have a guide for that too. New to MCP? Our WordPress MCP FAQ covers the basics.

The bill

• OpenCode: $0Open source, runs in your terminal, no sign-up.
• The AI model: $0OpenCode ships free models, like Big Pickle.
• AI Engine: $0The free plugin includes the MCP server and 45 tools.

1. Turn on MCP in AI Engine

Install AI Engine from Plugins → Add New. On a fresh install, MCP is already on. If you’ve had AI Engine for a while, open Meow Apps → AI Engine → Modules and tick MCP in the MCP & Agents block. Your server address appears right under it.

Copy that address. It always looks like this, with your own domain:

https://yoursite.com/wp-json/mcp/v1/http

2. Install OpenCode

One line in your terminal, on macOS or Linux:

curl -fsSL https://opencode.ai/install | bash

Already have Node.js? npm install -g opencode-ai works too, on Windows as well.

3. Tell OpenCode about your site

Create a file called opencode.json in the folder where you’ll work (or in ~/.config/opencode/opencode.json to have your site everywhere), with your own address in it:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "wordpress": {
      "type": "remote",
      "url": "https://yoursite.com/wp-json/mcp/v1/http"
    }
  }
}

Notice what’s missing: no token, no password. That’s on purpose, you’ll sign in the friendly way in the next step.

4. Sign in with your WordPress account

Make sure you’re logged in to your WordPress admin in your browser, then run this in the same folder:

opencode mcp auth wordpress

Your browser opens on your own site and asks if OpenCode may connect. Pick Full access to let it write, or Read-only to let it look around first, then click Approve.

That’s it, you’re connected. To check, opencode mcp list now shows ✓ wordpress connected.

5. Pick a free model and have fun

Start OpenCode with opencode, type /models and pick Big Pickle, or any model marked as free. Then just talk to it. For my test, I asked for something a bit silly:

It noticed that the Cats category didn’t exist, created it, wrote the post, saved it as a draft and filed it. Four tools, about fifty seconds, zero dollars. And here’s the post, waiting for me in WordPress:

It even invented a cat named Mochi. I like her already 😺

Things to try

• List my 10 latest posts and tell me which ones have no featured image.
• Find the posts without a category and suggest one for each.
• Show me the comments waiting for moderation, and draft a friendly reply to each.
• Write a draft about our spring menu, with three short sections and a few tags.
• Read my About page and tell me what’s unclear for a first-time visitor.

The free version of AI Engine gives OpenCode 45 tools: posts, pages, media, comments, users, categories and tags, settings and more. With Pro, it’s more than 130, with plugins, themes, WooCommerce, Polylang and the SEO Engine analytics. All the details are in the MCP facts.

Good to know

• Free models have a catch. They’re free for a limited time, and OpenCode says the data they collect during that time may be used to improve the model. Perfect for a blog post, not for anything secret. OpenCode also works with every big AI provider, and if AI Engine Pro already holds your keys, OpenCode can use the models from your WordPress.
• Full access means full access. The agent can edit and delete anything your account can. Start with Read-only, or on a test site, and ask for drafts. You can cut the connection any time in AI Engine’s MCP tab.
• Your site needs real HTTPS. A local site with a self-signed certificate won’t connect out of the box. If OpenCode can’t reach your site, this troubleshooting guide covers the usual suspects.

Questions

Curious what this looks like day to day? Here is how I run my own travel site with an agent over MCP.

Have fun, and tell me what you build with it 🙂