Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Unione MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.
Table of Contents
Connect Unione without Auth hassles
We manage OAuth, API Key, token refresh, and scopes, you just build.
Try for FreeIntroduction
Also integrate Unione with
Why use Composio?
Apart from a managed and hosted MCP server, you will get:
- CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
- Large tool responses: Handle them to minimise context rot.
- Dynamic just-in-time access to 20,000 tools across 870+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.
How to install Unione MCP in Codex
Run the setup command
Run this command in your terminal to add the Composio MCP server to Codex.
It will initiate the authentication in a browser window, authorize Codex to access your Composio account.
(Optional) Authenticate with OAuth
To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.
Verify the connection
Run codex mcp list to confirm Composio appears as a registered MCP server.
Codex App
Codex App follows the same approach as VS Code.
- Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
- Fill the header and Key fields with
{ "x-consumer-api-key" = "ck_*******" }. - The Key is the Composio API key, that you can find on connect.composio.dev
- Click on Authenticate and authorize Codex to your Composio account and you're all set.
- Restart and verify if it's there in
.codex/config.toml
What is the Unione MCP server, and what's possible with it?
The Unione MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Unione account. It provides structured and secure access to your Unione email delivery service, so your agent can send transactional or marketing emails, manage sending domains, monitor delivery events, check account balance, and automate email operations on your behalf.
- Automated email sending and scheduling: Have your agent send transactional or marketing emails and even schedule deliveries right from your Unione account.
- Domain verification and management: Easily manage sender domains, trigger domain verifications, and handle DNS/DKIM checks to keep your emails deliverable.
- Event monitoring and export: Let your agent fetch specific email events, retrieve delivery metrics, or export comprehensive email event logs for auditing and analytics.
- Account balance and plan checks: Quickly access your current email balance and subscription plan details, ensuring you stay within your sending limits.
- Email job and pricing insights: Retrieve detailed information about specific email jobs and get up-to-date pricing for cost management before sending campaigns.
Supported Tools & Triggers
Conclusion
You've successfully integrated Unione with Codex using Composio's MCP server. Now you can interact with Unione directly from your terminal, VS Code, or the Codex App using natural language commands.
Key benefits of this setup:
- Seamless integration across CLI, VS Code, and standalone app
- Natural language commands for Unione operations
- Managed authentication through Composio
- Access to 20,000+ tools across 870+ apps for cross-app workflows
- CodeAct workbench for complex tool chaining
Next steps:
- Try asking Codex to perform various Unione operations
- Explore cross-app workflows by connecting more toolkits
- Build automation scripts that leverage Codex's AI capabilities










