Synta MCP Codex Plugin

April 3, 2026 ยท View on GitHub

This plugin bundles the Synta MCP for Codex, which enables Codex to build, validate, & debug n8n workflows with deep knowledge of the platform's complete node library, allowing smart workflow-creation real-time error checking & expert troubleshooting assistance.

What This Plugin Includes

  • SKILL.MD: reusable instructions for building and repairing n8n workflows with Synta MCP
  • .mcp.json: MCP server definition for https://mcp.synta.io/mcp
  • .codex-plugin/plugin.json: Codex plugin manifest

Install In Codex

Codex plugins are installed from the plugin directory in the app or CLI. In the CLI, open the plugin list with:

codex
/plugins

For this local plugin, use the local plugin layout described by the Codex plugin manifest and marketplace conventions.

Option 1: Home-Local Install

Recommended when you want this plugin available across projects on your machine.

  1. Create the local plugins folders if they do not exist:
mkdir -p ~/.agents/plugins ~/.codex/plugins
  1. Copy this plugin into your local plugins directory:
cp -R /path/to/codex/plugin/n8n-mcp-codex-plugin-synta ~/.codex/plugins/n8n-mcp-codex-plugin-synta
  1. Create or update ~/.agents/plugins/marketplace.json with an entry for this plugin:
{
  "name": "local-plugins",
  "interface": {
    "displayName": "Local Plugins"
  },
  "plugins": [
    {
      "name": "n8n-mcp-synta-codex",
      "source": {
        "source": "local",
        "path": "./plugins/n8n-mcp-codex-plugin-synta"
      },
      "policy": {
        "installation": "AVAILABLE",
        "authentication": "ON_INSTALL"
      },
      "category": "Productivity"
    }
  ]
}

  1. Restart Codex.

  2. Open the plugin directory with /plugins, find Synta MCP, and install it.

Option 2: Repo-Local Install

Useful if you want to keep the plugin alongside a specific repo instead of your home directory.

  1. Place the plugin at:
<repo-root>/plugins/n8n-mcp-codex-plugin-synta
  1. Create or update:
<repo-root>/.agents/plugins/marketplace.json
  1. Add the same plugin entry as above, keeping the source path as:
"path": "./plugins/n8n-mcp-codex-plugin-synta"
  1. Restart Codex, then install it from /plugins.

Use The Plugin

After installation, start a new Codex thread and either:

  • Describe the outcome you want, for example: Build an n8n workflow that syncs Typeform submissions to HubSpot
  • Invoke the plugin or skill explicitly with @

Example prompts:

  • Use Synta MCP to create an n8n workflow that watches Gmail and posts new support emails to Slack
  • @synta-n8n-assistant fix the expression errors in this n8n workflow

Disable Or Uninstall

To disable the plugin without uninstalling it, set it to disabled in ~/.codex/config.toml and restart Codex:

[plugins."n8n-mcp-synta-codex"]
enabled = false

To remove it completely, uninstall it from the Codex plugin browser.